diff --git a/bgworker_test.go b/bgworker_test.go
new file mode 100644
index 0000000000..63b74f6919
--- /dev/null
+++ b/bgworker_test.go
@@ -0,0 +1,697 @@
+package frankenphp_test
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/dunglas/frankenphp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// requireFileEventually asserts that `path` appears on disk before the
+// deadline. Wraps require.Eventually so call sites stay short.
+func requireFileEventually(t testing.TB, path string, msgAndArgs ...any) {
+	t.Helper()
+	require.Eventually(t, func() bool {
+		_, err := os.Stat(path)
+		return err == nil
+	}, 5*time.Second, 25*time.Millisecond, msgAndArgs...)
+}
+
+// requireFileContentEventually waits for `path` to appear with content and
+// returns it
+func requireFileContentEventually(t *testing.T, path string) string {
+	t.Helper()
+	require.Eventually(t, func() bool {
+		b, err := os.ReadFile(path)
+		return err == nil && len(b) > 0
+	}, 5*time.Second, 25*time.Millisecond, "file %q did not appear", path)
+	b, err := os.ReadFile(path)
+	require.NoError(t, err)
+
+	return string(b)
+}
+
+// TestBackgroundWorkerLifecycle boots a background worker that touches a
+// sentinel file then parks on its handle. It proves the bg worker runs
+// (sentinel appears) and that Shutdown returns within a reasonable time.
+// The test asserts on Shutdown timing, so it manages Shutdown itself
+// instead of using initServers' t.Cleanup hook.
+func TestBackgroundWorkerLifecycle(t *testing.T) {
+	tmp := t.TempDir()
+	sentinel := filepath.Join(tmp, "bg-lifecycle.sentinel")
+
+	require.NoError(t, frankenphp.Init(
+		frankenphp.WithWorkers("bg-lifecycle", "testdata/bgworker/basic.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	))
+
+	requireFileEventually(t, sentinel, "background worker did not touch sentinel")
+
+	done := make(chan struct{})
+	go func() {
+		frankenphp.Shutdown()
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+		t.Fatalf("Shutdown did not return within 10s")
+	}
+}
+
+// TestBackgroundWorkerCrashRestarts boots a worker that exit(1)s on its
+// first run and touches a "restarted" sentinel on its second run. The
+// sentinel proves the crash-restart loop fired.
+func TestBackgroundWorkerCrashRestarts(t *testing.T) {
+	tmp := t.TempDir()
+	crashMarker := filepath.Join(tmp, "bg-crash.marker")
+	restarted := filepath.Join(tmp, "bg-crash.restarted")
+
+	initServers(t,
+		frankenphp.WithWorkers("bg-crash", "testdata/bgworker/crash.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{
+				"BG_CRASH_MARKER":       crashMarker,
+				"BG_RESTARTED_SENTINEL": restarted,
+			}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+
+	requireFileEventually(t, restarted, "background worker did not restart after crash")
+}
+
+// TestBackgroundWorkerOnServer scopes a background worker to a Server. It
+// proves that the worker inherits the server env (the sentinel directory is
+// declared on the server, not on the worker), that FRANKENPHP_WORKER_BACKGROUND
+// holds the worker name, and that the worker does not intercept HTTP requests
+// served by the same server.
+func TestBackgroundWorkerOnServer(t *testing.T) {
+	tmp := t.TempDir()
+
+	server, err := frankenphp.NewServer(
+		testDataDir,
+		frankenphp.WithServerName("sidekick-server"),
+		frankenphp.WithServerEnv(map[string]string{"BG_SENTINEL_DIR": tmp}),
+	)
+	require.NoError(t, err)
+
+	globalSentinel := filepath.Join(tmp, "global.sentinel")
+	initServers(t,
+		frankenphp.WithServer(server),
+		frankenphp.WithWorkers("jobs", "testdata/bgworker/named.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerServerScope(server),
+		),
+		// a global worker may reuse the name: names are scoped to their server
+		frankenphp.WithWorkers("jobs", "testdata/bgworker/basic.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": globalSentinel}),
+		),
+		frankenphp.WithNumThreads(3),
+	)
+
+	// named.php touches "<BG_SENTINEL_DIR>/<FRANKENPHP_WORKER_BACKGROUND>": the script sees
+	// the declared name, not the server-qualified one used by metrics and logs
+	requireFileEventually(t, filepath.Join(tmp, "jobs"), "background worker did not touch its per-name sentinel")
+	requireFileEventually(t, globalSentinel, "the global worker sharing the name did not start")
+
+	body := serverGet(t, server, "http://example.com/index.php")
+	assert.Contains(t, body, "I am by birth a Genevese", "the server must still serve regular requests")
+}
+
+// TestBackgroundWorkerValidation covers the declaration-time errors.
+func TestBackgroundWorkerValidation(t *testing.T) {
+	t.Cleanup(frankenphp.Shutdown)
+
+	t.Run("name is required", func(t *testing.T) {
+		err := frankenphp.Init(
+			frankenphp.WithWorkers("", "testdata/bgworker/basic.php", 1, frankenphp.WithWorkerBackground()),
+			frankenphp.WithNumThreads(2),
+		)
+		require.ErrorContains(t, err, "must have an explicit name")
+	})
+
+	t.Run("names are unique within a server", func(t *testing.T) {
+		// a global and a server-scoped worker may share a name (see
+		// TestBackgroundWorkerOnServer), two workers of one server may not
+		server, err := frankenphp.NewServer(testDataDir)
+		require.NoError(t, err)
+		err = frankenphp.Init(
+			frankenphp.WithServer(server),
+			frankenphp.WithWorkers("bg-shared", "testdata/bgworker/basic.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerServerScope(server),
+			),
+			frankenphp.WithWorkers("bg-shared", "testdata/bgworker/named.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerServerScope(server),
+			),
+			frankenphp.WithNumThreads(3),
+		)
+		require.ErrorContains(t, err, "two workers in a server cannot have the same name")
+	})
+
+	t.Run("early return without the handle fails startup", func(t *testing.T) {
+		err := frankenphp.Init(
+			frankenphp.WithWorkers("bg-early", "testdata/bgworker/early-return.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerMaxFailures(2),
+			),
+			frankenphp.WithNumThreads(2),
+		)
+		require.ErrorContains(t, err, "without calling frankenphp_worker_tick()")
+	})
+
+	t.Run("fetching the handle without ticking fails startup", func(t *testing.T) {
+		err := frankenphp.Init(
+			frankenphp.WithWorkers("bg-no-tick", "testdata/bgworker/fetch-no-tick.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerMaxFailures(2),
+			),
+			frankenphp.WithNumThreads(2),
+		)
+		require.ErrorContains(t, err, "without calling frankenphp_worker_tick()")
+	})
+
+	t.Run("max_threads is rejected", func(t *testing.T) {
+		err := frankenphp.Init(
+			frankenphp.WithWorkers("bg-scaled", "testdata/bgworker/basic.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerMaxThreads(2),
+			),
+			frankenphp.WithNumThreads(2),
+		)
+		require.ErrorContains(t, err, "cannot set max_threads")
+	})
+
+	t.Run("two workers cannot report under the same name", func(t *testing.T) {
+		// scoping keeps names apart, except for a global name shaped like
+		// the "<server>:<name>" of a scoped one
+		server, err := frankenphp.NewServer(testDataDir, frankenphp.WithServerName("api"))
+		require.NoError(t, err)
+		err = frankenphp.Init(
+			frankenphp.WithServer(server),
+			frankenphp.WithWorkers("jobs", "testdata/bgworker/basic.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerServerScope(server),
+			),
+			frankenphp.WithWorkers("api:jobs", "testdata/bgworker/named.php", 1,
+				frankenphp.WithWorkerBackground(),
+			),
+			frankenphp.WithNumThreads(3),
+		)
+		require.ErrorContains(t, err, `two workers cannot report under the same name: "api:jobs"`)
+	})
+
+	t.Run("an unregistered server scope is rejected", func(t *testing.T) {
+		unregistered, err := frankenphp.NewServer(testDataDir)
+		require.NoError(t, err)
+		err = frankenphp.Init(
+			frankenphp.WithWorkers("bg-orphan", "testdata/bgworker/basic.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerServerScope(unregistered),
+			),
+			frankenphp.WithNumThreads(2),
+		)
+		require.ErrorContains(t, err, "not passed to WithServer()")
+	})
+
+	t.Run("request matchers are rejected", func(t *testing.T) {
+		err := frankenphp.Init(
+			frankenphp.WithWorkers("bg-matched", "testdata/bgworker/basic.php", 1,
+				frankenphp.WithWorkerBackground(),
+				frankenphp.WithWorkerMatcher(func(*http.Request) bool { return true }),
+			),
+			frankenphp.WithNumThreads(2),
+		)
+		require.ErrorContains(t, err, "cannot match requests")
+	})
+}
+
+// TestBackgroundWorkerCannotHandleRequests checks that a request targeting a
+// background worker by name is refused rather than dispatched to it.
+func TestBackgroundWorkerCannotHandleRequests(t *testing.T) {
+	server, err := frankenphp.NewServer(testDataDir)
+	require.NoError(t, err)
+	initServers(t,
+		frankenphp.WithServer(server),
+		frankenphp.WithWorkers("jobs", "testdata/bgworker/basic.php", 1, frankenphp.WithWorkerBackground(), frankenphp.WithWorkerServerScope(server)),
+		frankenphp.WithNumThreads(2),
+	)
+
+	err = server.ServeHTTP(httptest.NewRecorder(), httptest.NewRequest(http.MethodGet, "http://example.com/index.php", nil), frankenphp.WithWorkerName("jobs"))
+	require.ErrorContains(t, err, `background worker "jobs" cannot handle requests`)
+}
+
+// TestBackgroundWorkerParksOnRead checks that a blocking read on the handle
+// is a wait too: Init() returns only once the worker is ready, and the EOF
+// of the drain unblocks the read so Shutdown() returns promptly.
+func TestBackgroundWorkerParksOnRead(t *testing.T) {
+	tmp := t.TempDir()
+	sentinel := filepath.Join(tmp, "bg-read.sentinel")
+
+	require.NoError(t, frankenphp.Init(
+		frankenphp.WithWorkers("bg-read", "testdata/bgworker/read.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	))
+	requireFileEventually(t, sentinel, "background worker parked on a read did not start")
+
+	done := make(chan struct{})
+	go func() {
+		frankenphp.Shutdown()
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+		t.Fatal("Shutdown did not return within 10s: the read did not observe EOF")
+	}
+}
+
+// TestBackgroundWorkerParksOnReceive checks that a blocking receive counts
+// as a wait as well: it reaches the stream through the transport API rather
+// than the read op, so Init() would hang if only reads reported readiness.
+func TestBackgroundWorkerParksOnReceive(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "bg-recv.sentinel")
+
+	require.NoError(t, frankenphp.Init(
+		frankenphp.WithWorkers("bg-recv", "testdata/bgworker/recv.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	))
+	requireFileEventually(t, sentinel, "background worker parked on a receive did not start")
+
+	done := make(chan struct{})
+	go func() {
+		frankenphp.Shutdown()
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+		t.Fatal("Shutdown did not return within 10s: the receive did not observe EOF")
+	}
+}
+
+// TestBackgroundWorkerRestartDrainsParkedScript checks that RestartWorkers()
+// wakes a parked background script through the drain and re-runs it.
+func TestBackgroundWorkerRestartDrainsParkedScript(t *testing.T) {
+	tmp := t.TempDir()
+	countFile := filepath.Join(tmp, "bg-count.log")
+
+	initServers(t,
+		frankenphp.WithWorkers("bg-count", "testdata/bgworker/count.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_COUNT_FILE": countFile}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+	runs := func() int {
+		b, _ := os.ReadFile(countFile)
+		return bytes.Count(b, []byte("\n"))
+	}
+	require.Eventually(t, func() bool { return runs() == 1 }, 5*time.Second, 25*time.Millisecond, "background worker did not start")
+
+	frankenphp.RestartWorkers()
+
+	require.Eventually(t, func() bool { return runs() == 2 }, 5*time.Second, 25*time.Millisecond, "background worker was not re-run after the restart")
+}
+
+// TestGetWorkerHandleOutsideBackgroundWorker checks the function throws on a
+// regular request thread instead of handing out a stream.
+func TestGetWorkerHandleOutsideBackgroundWorker(t *testing.T) {
+	server, err := frankenphp.NewServer(testDataDir)
+	require.NoError(t, err)
+	initServers(t, frankenphp.WithServer(server), frankenphp.WithNumThreads(1))
+
+	body := serverGet(t, server, "http://example.com/handle-outside.php")
+
+	assert.Contains(t, body, "frankenphp_get_worker_handle() can only be called from a background worker")
+	assert.Contains(t, body, "frankenphp_worker_tick() can only be called from a background worker")
+}
+
+// TestBackgroundWorkerLoopTicksOnItsOwn checks the wake-up sent at start: a
+// script that only ticks when its handle is readable, the shape of a script
+// driven by an event loop, becomes ready without an explicit first call.
+// Without the wake-up, Init() would wait for that call until the drain.
+func TestBackgroundWorkerLoopTicksOnItsOwn(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "loop.sentinel")
+	initServers(t,
+		frankenphp.WithWorkers("bg-loop", "testdata/bgworker/loop.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+	requireFileEventually(t, sentinel, "background worker did not start")
+}
+
+// TestBackgroundWorkerTickLeavesTheHandleQuiet checks that the tick
+// consumes the wake-ups: the handle is readable at start, and not anymore
+// once a tick returned, so a loop selecting on it blocks instead of
+// spinning.
+func TestBackgroundWorkerTickLeavesTheHandleQuiet(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "readable.txt")
+	initServers(t,
+		frankenphp.WithWorkers("bg-readable", "testdata/bgworker/readable.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+
+	assert.Equal(t, "start:readable after tick:quiet after second tick:quiet", requireFileContentEventually(t, sentinel))
+}
+
+// TestBackgroundWorkerTick checks the contract of frankenphp_worker_tick():
+// true while the worker runs, false once it is drained, and still false on
+// the next call
+func TestBackgroundWorkerTick(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "ticks.txt")
+
+	require.NoError(t, frankenphp.Init(
+		frankenphp.WithWorkers("bg-tick", "testdata/bgworker/tick.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	))
+	assert.Equal(t, "true true", requireFileContentEventually(t, sentinel))
+
+	// Shutdown() waits for the script to leave, so the file is final after it
+	frankenphp.Shutdown()
+	b, err := os.ReadFile(sentinel)
+	require.NoError(t, err)
+	assert.Equal(t, "true true false false", string(b))
+}
+
+// TestWorkerNameInServerVars checks that an HTTP worker sees FRANKENPHP_WORKER
+// as it always did, and that a background worker sees its declared name in
+// FRANKENPHP_WORKER_BACKGROUND and no FRANKENPHP_WORKER.
+func TestWorkerNameInServerVars(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "flag.txt")
+	server, err := frankenphp.NewServer(testDataDir)
+	require.NoError(t, err)
+	initServers(t,
+		frankenphp.WithServer(server),
+		frankenphp.WithWorkers("web", testDataDir+"worker-name.php", 1, frankenphp.WithWorkerServerScope(server)),
+		frankenphp.WithWorkers("jobs", "testdata/bgworker/flag.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerServerScope(server),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(3),
+	)
+
+	assert.Equal(t, "1 http", serverGet(t, server, "http://example.com/worker-name.php"))
+
+	flag := requireFileContentEventually(t, sentinel)
+	assert.Contains(t, flag, "'worker' => 'unset'")
+	assert.Contains(t, flag, "'background' => 'jobs'")
+}
+
+// TestBackgroundWorkerPool checks that num > 1 threads share the name, each
+// parks on its own handle, and one drain wakes them all.
+func TestBackgroundWorkerPool(t *testing.T) {
+	dir := t.TempDir()
+	initServers(t,
+		frankenphp.WithWorkers("pool", "testdata/bgworker/pool.php", 3,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL_DIR": dir}),
+		),
+		frankenphp.WithNumThreads(4),
+	)
+
+	require.Eventually(t, func() bool {
+		entries, _ := os.ReadDir(dir)
+		return len(entries) == 3
+	}, 5*time.Second, 25*time.Millisecond, "the three pool threads did not all start")
+
+	done := make(chan struct{})
+	go func() {
+		frankenphp.Shutdown()
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+		t.Fatal("Shutdown did not drain the whole pool within 10s")
+	}
+}
+
+// TestBackgroundWorkerMultiEntrypoint checks that two named background
+// workers of one server may share a script, since they are not matched by path.
+func TestBackgroundWorkerMultiEntrypoint(t *testing.T) {
+	tmp := t.TempDir()
+	first, second := filepath.Join(tmp, "first"), filepath.Join(tmp, "second")
+	server, err := frankenphp.NewServer(testDataDir)
+	require.NoError(t, err)
+	initServers(t,
+		frankenphp.WithServer(server),
+		frankenphp.WithWorkers("first", "testdata/bgworker/basic.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerServerScope(server),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": first}),
+		),
+		frankenphp.WithWorkers("second", "testdata/bgworker/basic.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerServerScope(server),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": second}),
+		),
+		frankenphp.WithNumThreads(3),
+	)
+
+	requireFileEventually(t, first, "the first worker on the shared script did not start")
+	requireFileEventually(t, second, "the second worker on the shared script did not start")
+}
+
+// TestBackgroundWorkerThreadsComeOnTop checks that background threads are
+// reserved on top of num_threads: one HTTP thread plus one background worker
+// starts with num_threads 1.
+func TestBackgroundWorkerThreadsComeOnTop(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "bg-only.sentinel")
+	initServers(t,
+		frankenphp.WithWorkers("bg-only", "testdata/bgworker/basic.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(1),
+	)
+
+	requireFileEventually(t, sentinel, "background worker did not start with num_threads 1")
+}
+
+// TestBackgroundWorkerDefaultsToOneThread checks that num is optional: a
+// background worker serves no requests, so it gets one thread unless a
+// pool is asked for, rather than the CPU count of an HTTP worker.
+func TestBackgroundWorkerDefaultsToOneThread(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "bg-default.sentinel")
+	initServers(t,
+		frankenphp.WithWorkers("bg-default", "testdata/bgworker/basic.php", 0,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(1),
+	)
+	requireFileEventually(t, sentinel, "background worker did not start without an explicit num")
+
+	background := 0
+	for _, thread := range frankenphp.DebugState().ThreadDebugStates {
+		if strings.Contains(thread.Name, "Background Worker") {
+			background++
+		}
+	}
+	assert.Equal(t, 1, background)
+}
+
+// TestBackgroundWorkerThreadsComeOnTopOfAutoMaxThreads checks that the
+// automatic limit is an HTTP one too: the reservation is added to what it
+// resolves, instead of eating into it
+func TestBackgroundWorkerThreadsComeOnTopOfAutoMaxThreads(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "bg-auto.sentinel")
+	initServers(t,
+		frankenphp.WithWorkers("bg-auto", "testdata/bgworker/basic.php", 2,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+		frankenphp.WithMaxThreads(-1),
+		frankenphp.WithPhpIni(map[string]string{"memory_limit": "-1"}),
+	)
+	requireFileEventually(t, sentinel, "background worker did not start")
+
+	// an unlimited memory_limit falls back to twice the HTTP threads, so
+	// 2*2 HTTP plus the 2 reserved, not (2+2)*2
+	state := frankenphp.DebugState()
+	assert.Equal(t, 6, len(state.ThreadDebugStates)+state.ReservedThreadCount)
+}
+
+// TestBackgroundWorkerBootstrapIsBounded checks that max_execution_time
+// applies until the first frankenphp_worker_tick(): a setup that outlives
+// it is ended as a boot failure, which fails Init() past the cap. The limit
+// itself is PHP's, so the test only runs where its timers are known to
+// fire under FrankenPHP, the max execution timers of ZTS builds on Linux.
+func TestBackgroundWorkerBootstrapIsBounded(t *testing.T) {
+	if !frankenphp.Config().ZendMaxExecutionTimers {
+		t.Skip("max_execution_time is only reliable with Zend max execution timers")
+	}
+
+	countFile := filepath.Join(t.TempDir(), "boots")
+	err := frankenphp.Init(
+		frankenphp.WithWorkers("bg-slow", "testdata/bgworker/slow-boot.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerMaxFailures(0),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_COUNT_FILE": countFile}),
+		),
+		frankenphp.WithNumThreads(2),
+		frankenphp.WithPhpIni(map[string]string{"max_execution_time": "1"}),
+	)
+	if err == nil {
+		frankenphp.Shutdown()
+	}
+	require.ErrorContains(t, err, "keeps crashing")
+
+	b, _ := os.ReadFile(countFile)
+	assert.Equal(t, 1, bytes.Count(b, []byte("\n")), "the limit should have ended the one and only boot")
+}
+
+// TestBackgroundWorkerParkingIsNotInterrupted checks that a script parked
+// on its handle, past its first tick, is not cut short by the two limits it
+// never disables itself: max_execution_time, which the first tick disarms
+// after php_execute_script() re-armed it from the ini, and
+// default_socket_timeout, which the handle overrides with an infinite read
+// timeout.
+func TestBackgroundWorkerParkingIsNotInterrupted(t *testing.T) {
+	countFile := filepath.Join(t.TempDir(), "runs")
+	initServers(t,
+		frankenphp.WithWorkers("bg-timeout", "testdata/bgworker/no-time-limit.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_COUNT_FILE": countFile}),
+		),
+		frankenphp.WithNumThreads(2),
+		frankenphp.WithPhpIni(map[string]string{"max_execution_time": "1", "max_input_time": "1", "default_socket_timeout": "1"}),
+	)
+
+	runs := func() int {
+		b, _ := os.ReadFile(countFile)
+
+		return bytes.Count(b, []byte("\n"))
+	}
+	require.Eventually(t, func() bool { return runs() == 1 }, 5*time.Second, 25*time.Millisecond, "background worker did not start")
+	// well past both limits
+	time.Sleep(2500 * time.Millisecond)
+	assert.Equal(t, 1, runs(), "the worker was restarted, so a limit interrupted its park")
+}
+
+// TestBackgroundWorkerHandleClosedAndFetchedAgain checks the handle cache:
+// a run gets one stream, closing it yields a fresh one on the next fetch,
+// and the drain still reaches the script through it.
+func TestBackgroundWorkerHandleClosedAndFetchedAgain(t *testing.T) {
+	sentinel := filepath.Join(t.TempDir(), "refetch.txt")
+
+	require.NoError(t, frankenphp.Init(
+		frankenphp.WithWorkers("bg-refetch", "testdata/bgworker/refetch.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	))
+	assert.Equal(t, "same then fresh", requireFileContentEventually(t, sentinel))
+
+	done := make(chan struct{})
+	go func() {
+		frankenphp.Shutdown()
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(10 * time.Second):
+		t.Fatal("Shutdown did not return within 10s: the re-fetched handle missed the drain")
+	}
+}
+
+// TestBackgroundWorkerBootFailuresThenSucceeds checks that boot failures below
+// max_consecutive_failures are retried with the backoff and Init() still
+// succeeds once a run reaches its ready point.
+func TestBackgroundWorkerBootFailuresThenSucceeds(t *testing.T) {
+	tmp := t.TempDir()
+	countFile, sentinel := filepath.Join(tmp, "boots"), filepath.Join(tmp, "ready")
+	initServers(t,
+		frankenphp.WithWorkers("bg-flaky", "testdata/bgworker/fail-then-succeed.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_COUNT_FILE": countFile, "BG_SENTINEL": sentinel, "BG_FAIL_UNTIL": "2"}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+
+	requireFileEventually(t, sentinel, "background worker did not recover from its boot failures")
+	boots, err := os.ReadFile(countFile)
+	require.NoError(t, err)
+	assert.Equal(t, "3", string(boots), "two boot failures then a success")
+}
+
+// TestBackgroundWorkerCrashAfterReadyRestarts checks that a crash after the
+// ready point restarts right away without counting toward
+// max_consecutive_failures, and that a zero-timeout stream_select() counts
+// as the wait.
+func TestBackgroundWorkerCrashAfterReadyRestarts(t *testing.T) {
+	countFile := filepath.Join(t.TempDir(), "runs")
+	initServers(t,
+		frankenphp.WithWorkers("bg-crashy", "testdata/bgworker/crash-after-ready.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerMaxFailures(2),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_COUNT_FILE": countFile}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+
+	require.Eventually(t, func() bool {
+		b, _ := os.ReadFile(countFile)
+		return bytes.Count(b, []byte("\n")) >= 4
+	}, 5*time.Second, 25*time.Millisecond, "the worker was not restarted after crashing past its ready point")
+}
+
+// TestBackgroundWorkerRebootForceKillsStuckScript checks that a script
+// ignoring its handle does not stall RestartWorkers() past the reboot grace
+// period: the force-kill ends it and the next run parks normally.
+func TestBackgroundWorkerRebootForceKillsStuckScript(t *testing.T) {
+	if runtime.GOOS != "linux" && runtime.GOOS != "freebsd" {
+		t.Skipf("force-kill cannot interrupt a blocking syscall on %s", runtime.GOOS)
+	}
+
+	tmp := t.TempDir()
+	once, sentinel := filepath.Join(tmp, "once"), filepath.Join(tmp, "parked")
+	initServers(t,
+		frankenphp.WithWorkers("bg-stuck", "testdata/bgworker/stuck.php", 1,
+			frankenphp.WithWorkerBackground(),
+			frankenphp.WithWorkerEnv(map[string]string{"BG_ONCE": once, "BG_SENTINEL": sentinel}),
+		),
+		frankenphp.WithNumThreads(2),
+	)
+	requireFileEventually(t, once, "background worker never entered its sleep")
+
+	start := time.Now()
+	frankenphp.RestartWorkers()
+	assert.WithinDuration(t, start, time.Now(), 10*time.Second, "the reboot must force-kill the stuck script within its grace period")
+
+	requireFileEventually(t, sentinel, "the re-run script did not park")
+}
diff --git a/caddy/app.go b/caddy/app.go
index fcee129180..88636401c4 100644
--- a/caddy/app.go
+++ b/caddy/app.go
@@ -17,7 +17,6 @@ import (
 	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
 	"github.com/dunglas/frankenphp"
-	"github.com/dunglas/frankenphp/internal/fastabs"
 )
 
 var (
@@ -60,15 +59,14 @@ type FrankenPHPApp struct {
 	// EXPERIMENTAL: MaxRequests sets the maximum number of requests a PHP thread handles before restarting (0 = unlimited)
 	MaxRequests int `json:"max_requests,omitempty"`
 
-	opts            []frankenphp.Option
-	metrics         frankenphp.Metrics
-	ctx             context.Context
-	logger          *slog.Logger
-	modules         []*FrankenPHPModule
-	usedWorkerNames map[string]bool
-	httpApp         *caddyhttp.App
-	hasStarted      atomic.Bool
-	started         chan any
+	opts       []frankenphp.Option
+	metrics    frankenphp.Metrics
+	ctx        context.Context
+	logger     *slog.Logger
+	modules    []*FrankenPHPModule
+	httpApp    *caddyhttp.App
+	hasStarted atomic.Bool
+	started    chan any
 }
 
 var errIni = errors.New(`"php_ini" must be in the format: php_ini "<key>" "<value>"`)
@@ -133,7 +131,6 @@ func (f *FrankenPHPApp) Start() error {
 	// register global workers
 	for _, w := range f.Workers {
 		w.FileName = repl.ReplaceKnown(w.FileName, "")
-		w.Name = f.createUniqueWorkerName(w, "")
 		opts, err := w.toWorkerOptions()
 		if err != nil {
 			return err
@@ -224,7 +221,6 @@ func (f *FrankenPHPApp) registerModule(repl *caddy.Replacer, module *FrankenPHPM
 
 	for _, w := range module.Workers {
 		w.FileName = repl.ReplaceKnown(w.FileName, "")
-		w.Name = f.createUniqueWorkerName(w, serverName)
 		workerOptions, err := w.toWorkerOptions()
 		if err != nil {
 			return err
@@ -236,37 +232,6 @@ func (f *FrankenPHPApp) registerModule(repl *caddy.Replacer, module *FrankenPHPM
 	return nil
 }
 
-// avoid name collisions for workers
-// on collision, a name is first qualified with the server name
-// ("<serverName>:<name>") before falling back to a numeric postfix
-func (f *FrankenPHPApp) createUniqueWorkerName(wc workerConfig, serverName string) string {
-	if f.usedWorkerNames == nil {
-		f.usedWorkerNames = make(map[string]bool)
-	}
-
-	if wc.Name == "" {
-		wc.Name, _ = fastabs.FastAbs(wc.FileName)
-	}
-
-	name := wc.Name
-	suffix := 0
-	for {
-		if _, ok := f.usedWorkerNames[name]; !ok {
-			f.usedWorkerNames[name] = true
-			break
-		}
-		if serverName != "" {
-			name = serverName + ":" + wc.Name
-			serverName = ""
-			continue
-		}
-		suffix++
-		name = fmt.Sprintf("%s_%d", wc.Name, suffix)
-	}
-
-	return name
-}
-
 // UnmarshalCaddyfile implements caddyfile.Unmarshaler.
 func (f *FrankenPHPApp) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 	for d.Next() {
@@ -381,10 +346,13 @@ func (f *FrankenPHPApp) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				if len(wc.MatchPath) != 0 {
 					return d.Errf(`"match" can only be used in a php_server worker block, not in a global one: %q`, wc.FileName)
 				}
-				// check for duplicate workers
-				for _, existingWorker := range f.Workers {
-					if existingWorker.FileName == wc.FileName {
-						return d.Errf("global workers must not have duplicate filenames: %q", wc.FileName)
+				// check for duplicate workers; background workers are keyed
+				// by name, several may share a script
+				if !wc.Background {
+					for _, existingWorker := range f.Workers {
+						if !existingWorker.Background && existingWorker.FileName == wc.FileName {
+							return d.Errf("global workers must not have duplicate filenames: %q", wc.FileName)
+						}
 					}
 				}
 
diff --git a/caddy/caddy_test.go b/caddy/caddy_test.go
index b7d6c231eb..43ac10513e 100644
--- a/caddy/caddy_test.go
+++ b/caddy/caddy_test.go
@@ -757,6 +757,45 @@ func TestMetrics(t *testing.T) {
 	require.NoError(t, testutil.GatherAndCompare(ctx.GetMetricsRegistry(), strings.NewReader(expectedMetrics), "frankenphp_total_threads", "frankenphp_busy_threads"))
 }
 
+// TestBackgroundWorkerFromCaddyfile starts a background worker from a
+// Caddyfile and checks it runs: the sentinel its script touches appears
+func TestBackgroundWorkerFromCaddyfile(t *testing.T) {
+	sentinel := filepath.ToSlash(filepath.Join(t.TempDir(), "bg.sentinel"))
+	tester := caddytest.NewTester(t)
+	initServer(t, tester, `
+	{
+		skip_install_trust
+		admin localhost:2999
+		http_port `+testPort+`
+		https_port 9443
+
+		frankenphp {
+			worker {
+				file ../testdata/bgworker/basic.php
+				num 1
+				name bg-caddy
+				background
+				env BG_SENTINEL `+sentinel+`
+			}
+		}
+	}
+
+	localhost:`+testPort+` {
+		route {
+			php {
+				root ../testdata
+			}
+		}
+	}
+	`, "caddyfile")
+
+	require.Eventually(t, func() bool {
+		_, err := os.Stat(sentinel)
+
+		return err == nil
+	}, 5*time.Second, 25*time.Millisecond, "the background worker declared in the Caddyfile did not run")
+}
+
 func TestWorkerMetrics(t *testing.T) {
 	var wg sync.WaitGroup
 	tester := caddytest.NewTester(t)
@@ -839,7 +878,7 @@ func TestWorkerMetrics(t *testing.T) {
 	# TYPE frankenphp_worker_request_count counter
 	frankenphp_worker_request_count{worker="` + workerName + `"} 10
 
-	# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+	# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 	# TYPE frankenphp_ready_workers gauge
 	frankenphp_ready_workers{worker="` + workerName + `"} 2
 	`
@@ -996,7 +1035,7 @@ func TestNamedWorkerMetrics(t *testing.T) {
 	# TYPE frankenphp_worker_request_count counter
 	frankenphp_worker_request_count{worker="my_app"} 10
 
-	# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+	# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 	# TYPE frankenphp_ready_workers gauge
 	frankenphp_ready_workers{worker="my_app"} 2
 	`
@@ -1092,7 +1131,7 @@ func TestAutoWorkerConfig(t *testing.T) {
 	# TYPE frankenphp_worker_request_count counter
 	frankenphp_worker_request_count{worker="` + workerName + `"} 10
 
-	# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+	# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 	# TYPE frankenphp_ready_workers gauge
 	frankenphp_ready_workers{worker="` + workerName + `"} ` + workers + `
 	`
@@ -1460,7 +1499,7 @@ func TestMultiWorkersMetrics(t *testing.T) {
 	# TYPE frankenphp_worker_request_count counter
 	frankenphp_worker_request_count{worker="service1"} 10
 
-	# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+	# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 	# TYPE frankenphp_ready_workers gauge
 	frankenphp_ready_workers{worker="service1"} 2
 	frankenphp_ready_workers{worker="service2"} 3
@@ -1614,7 +1653,7 @@ func TestWorkerRestart(t *testing.T) {
 
 	// Check metrics
 	expectedMetrics := `
-	# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+	# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 	# TYPE frankenphp_ready_workers gauge
 	frankenphp_ready_workers{worker="service"} 1
 	# HELP frankenphp_total_workers Total number of PHP workers for this worker
@@ -1642,7 +1681,7 @@ func TestWorkerRestart(t *testing.T) {
 
 	// frankenphp_ready_workers should be back to 1 even after worker restarts
 	expectedMetrics = `
-	# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+	# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 	# TYPE frankenphp_ready_workers gauge
 	frankenphp_ready_workers{worker="service"} 1
 	# HELP frankenphp_total_workers Total number of PHP workers for this worker
@@ -2113,7 +2152,7 @@ func TestSymlinkWorkerBehavior(t *testing.T) {
 
 		// Accessing the worker script without worker configuration MUST fail
 		// The script checks $_SERVER['FRANKENPHP_WORKER'] and dies if not set
-		tester.AssertGetResponse("http://localhost:"+testPort+"/index.php", http.StatusOK, "Error: This script must be run in worker mode (FRANKENPHP_WORKER not set to '1')\n")
+		tester.AssertGetResponse("http://localhost:"+testPort+"/index.php", http.StatusOK, "Error: This script must be run in worker mode (FRANKENPHP_WORKER not set)\n")
 	})
 
 	t.Run("MultipleRequests", func(t *testing.T) {
diff --git a/caddy/config_test.go b/caddy/config_test.go
index 607051cbd8..933769fd78 100644
--- a/caddy/config_test.go
+++ b/caddy/config_test.go
@@ -1,7 +1,6 @@
 package caddy
 
 import (
-	"path/filepath"
 	"testing"
 	"time"
 
@@ -81,6 +80,45 @@ func TestModuleWorkerDuplicateFilenamesFail(t *testing.T) {
 	require.Contains(t, err.Error(), "must not have duplicate filenames", "Error message should mention duplicate filenames")
 }
 
+// two global background workers may share a script, like their php_server
+// counterparts and the Go API: they are keyed by name
+func TestGlobalBackgroundWorkersShareAFilename(t *testing.T) {
+	d := caddyfile.NewTestDispenser(`
+	{
+		frankenphp {
+			worker {
+				name first
+				file ../testdata/worker-with-env.php
+				num 1
+				background
+			}
+			worker {
+				name second
+				file ../testdata/worker-with-env.php
+				num 1
+				background
+			}
+		}
+	}`)
+	app := &FrankenPHPApp{}
+
+	require.NoError(t, app.UnmarshalCaddyfile(d))
+	require.Len(t, app.Workers, 2)
+}
+
+func TestGlobalWorkerDuplicateFilenamesFail(t *testing.T) {
+	d := caddyfile.NewTestDispenser(`
+	{
+		frankenphp {
+			worker ../testdata/worker-with-env.php
+			worker ../testdata/worker-with-env.php
+		}
+	}`)
+	app := &FrankenPHPApp{}
+
+	require.ErrorContains(t, app.UnmarshalCaddyfile(d), "must not have duplicate filenames")
+}
+
 func TestModuleWorkersWithDifferentFilenames(t *testing.T) {
 	// Create a test configuration with different worker filenames
 	configWithDifferentFilenames := `
@@ -249,38 +287,73 @@ func TestModuleWorkerWithCustomName(t *testing.T) {
 	require.Equal(t, "../testdata/worker-with-env.php", module.Workers[0].FileName, "Worker should have the correct filename")
 }
 
-func TestCreateUniqueWorkerNames(t *testing.T) {
-	app := &FrankenPHPApp{}
-	filename := "../testdata/worker-with-env.php"
-	absFileName, _ := filepath.Abs(filename)
-	names := make([]string, 6)
-	for i := range 3 {
-		names[i] = app.createUniqueWorkerName(workerConfig{
-			FileName: filename,
-			Name:     "custom-worker-name",
-		}, "")
-		names[i+3] = app.createUniqueWorkerName(workerConfig{
-			FileName: filename,
-		}, "")
-	}
-
-	require.Equal(t, "custom-worker-name", names[0])
-	require.Equal(t, "custom-worker-name_1", names[1])
-	require.Equal(t, "custom-worker-name_2", names[2])
-	require.Equal(t, absFileName, names[3])
-	require.Equal(t, absFileName+"_1", names[4])
-	require.Equal(t, absFileName+"_2", names[5])
+func TestWorkerBackgroundConfig(t *testing.T) {
+	d := caddyfile.NewTestDispenser(`
+	{
+		php_server {
+			worker {
+				name jobs
+				file ../testdata/worker-with-env.php
+				num 2
+				background
+			}
+		}
+	}`)
+	module := &FrankenPHPModule{}
+
+	require.NoError(t, module.UnmarshalCaddyfile(d))
+	require.Len(t, module.Workers, 1)
+	require.True(t, module.Workers[0].Background)
+	require.Equal(t, "jobs", module.Workers[0].Name)
 }
 
-func TestCreateUniqueWorkerNamesQualifiedByServer(t *testing.T) {
-	app := &FrankenPHPApp{}
-	wc := workerConfig{FileName: "../testdata/worker-with-env.php", Name: "queue"}
-
-	require.Equal(t, "queue", app.createUniqueWorkerName(wc, "one.example.com"))
-	// on collision, the name is qualified with the server name
-	require.Equal(t, "two.example.com:queue", app.createUniqueWorkerName(wc, "two.example.com"))
-	// when the qualified name is also taken, fall back to the numeric postfix
-	require.Equal(t, "queue_1", app.createUniqueWorkerName(wc, "two.example.com"))
-	// workers without a server keep the numeric postfix behavior
-	require.Equal(t, "queue_2", app.createUniqueWorkerName(wc, ""))
+func TestWorkerBackgroundRequiresName(t *testing.T) {
+	d := caddyfile.NewTestDispenser(`
+	{
+		php_server {
+			worker {
+				file ../testdata/worker-with-env.php
+				background
+			}
+		}
+	}`)
+	module := &FrankenPHPModule{}
+
+	err := module.UnmarshalCaddyfile(d)
+	require.ErrorContains(t, err, `background workers must have an explicit "name"`)
+}
+
+func TestWorkerBackgroundWithoutNumParses(t *testing.T) {
+	d := caddyfile.NewTestDispenser(`
+	{
+		php_server {
+			worker {
+				name jobs
+				file ../testdata/worker-with-env.php
+				background
+			}
+		}
+	}`)
+	module := &FrankenPHPModule{}
+
+	// num is optional, it defaults to one thread when the workers start
+	require.NoError(t, module.UnmarshalCaddyfile(d))
+}
+
+func TestWorkerBackgroundRejectsMatch(t *testing.T) {
+	d := caddyfile.NewTestDispenser(`
+	{
+		php_server {
+			worker {
+				name jobs
+				file ../testdata/worker-with-env.php
+				match /jobs/*
+				background
+			}
+		}
+	}`)
+	module := &FrankenPHPModule{}
+
+	err := module.UnmarshalCaddyfile(d)
+	require.ErrorContains(t, err, `"match" is not supported for background workers`)
 }
diff --git a/caddy/module.go b/caddy/module.go
index 20dcec9ee2..ff6e2db5ff 100644
--- a/caddy/module.go
+++ b/caddy/module.go
@@ -315,6 +315,10 @@ func (f *FrankenPHPModule) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 	// Check if a worker with this filename already exists in this module
 	fileNames := make(map[string]struct{}, len(f.Workers))
 	for _, w := range f.Workers {
+		// background workers are keyed by name, several may share a script
+		if w.Background {
+			continue
+		}
 		if _, ok := fileNames[w.FileName]; ok {
 			return fmt.Errorf(`workers in a single "php" or "php_server" block must not have duplicate filenames: %q`, w.FileName)
 		}
diff --git a/caddy/workerconfig.go b/caddy/workerconfig.go
index b39eb731e0..326b99a045 100644
--- a/caddy/workerconfig.go
+++ b/caddy/workerconfig.go
@@ -22,7 +22,7 @@ import (
 type workerConfig struct {
 	mercureContext
 
-	// Name for the worker. Default: the absolute path of the worker file, postfixed with a number if the name is already used.
+	// Name for the worker, unique within its php_server (or among global workers). Default: the absolute path of the worker file.
 	Name string `json:"name,omitempty"`
 	// FileName sets the path to the worker script.
 	FileName string `json:"file_name,omitempty"`
@@ -38,6 +38,8 @@ type workerConfig struct {
 	MatchPath []string `json:"match_path,omitempty"`
 	// MaxConsecutiveFailures sets the maximum number of consecutive failures before panicking (defaults to 6, set to -1 to never panick)
 	MaxConsecutiveFailures int `json:"max_consecutive_failures,omitempty"`
+	// Background marks this worker as a background (non-HTTP) worker.
+	Background bool `json:"background,omitempty"`
 
 	options []frankenphp.WorkerOption
 }
@@ -139,8 +141,10 @@ func unmarshalWorker(d *caddyfile.Dispenser) (workerConfig, error) {
 			}
 
 			wc.MaxConsecutiveFailures = v
+		case "background":
+			wc.Background = true
 		default:
-			return wc, wrongSubDirectiveError("worker", "name, file, num, env, watch, match, max_consecutive_failures, max_threads", v)
+			return wc, wrongSubDirectiveError("worker", "name, file, num, env, watch, match, max_consecutive_failures, max_threads, background", v)
 		}
 	}
 
@@ -148,6 +152,15 @@ func unmarshalWorker(d *caddyfile.Dispenser) (workerConfig, error) {
 		return wc, d.Err(`the "file" argument must be specified`)
 	}
 
+	if wc.Background {
+		if wc.Name == "" {
+			return wc, d.Err(`background workers must have an explicit "name"`)
+		}
+		if len(wc.MatchPath) != 0 {
+			return wc, d.Err(`"match" is not supported for background workers`)
+		}
+	}
+
 	if frankenphp.EmbeddedAppPath != "" && filepath.IsLocal(wc.FileName) {
 		wc.FileName = filepath.Join(frankenphp.EmbeddedAppPath, wc.FileName)
 	}
@@ -166,6 +179,10 @@ func (wc *workerConfig) toWorkerOptions() ([]frankenphp.WorkerOption, error) {
 	// options collected while provisioning the module, e.g. the Mercure hub
 	opts = append(opts, wc.options...)
 
+	if wc.Background {
+		opts = append(opts, frankenphp.WithWorkerBackground())
+	}
+
 	// copy the caddy match logic and create a unique matcher function for this worker
 	// inject the matcher into frankenphp
 	if len(wc.MatchPath) > 0 {
diff --git a/cgi.go b/cgi.go
index 85b6a4469a..25a7b87e44 100644
--- a/cgi.go
+++ b/cgi.go
@@ -225,7 +225,7 @@ func splitCgiPath(fc *frankenPHPContext) {
 	// see if a php_server worker or global worker matches the request path
 	// aka: root + request path == worker.filename
 	if fc.worker = fc.server.workersByPath[fc.scriptFilename]; fc.worker == nil {
-		fc.worker = globalWorkersByPath[fc.scriptFilename]
+		fc.worker = fallbackServer.workersByPath[fc.scriptFilename]
 	}
 }
 
diff --git a/context.go b/context.go
index d184965fea..b0fbcd52a4 100644
--- a/context.go
+++ b/context.go
@@ -130,20 +130,14 @@ func newWorkerDummyContext(w *worker) (*frankenPHPContext, error) {
 		return nil, err
 	}
 
-	server := w.server
-	if server == nil {
-		// global worker, not associated with a server
-		server = fallbackServer
-	}
-
 	fc := &frankenPHPContext{
 		done:      make(chan any),
 		ctx:       r.Context(),
-		server:    server,
+		server:    w.server,
 		request:   r,
 		startedAt: time.Now(),
 		// startup output of a scoped worker belongs to its server's logger
-		logger: server.logger,
+		logger: w.server.logger,
 		worker: w,
 	}
 
@@ -160,11 +154,6 @@ func newWorkerDummyContext(w *worker) (*frankenPHPContext, error) {
 
 // newContextFromMessage creates a context from a message (external workers)
 func newContextFromMessage(message any, rw http.ResponseWriter, ctx context.Context, w *worker) *frankenPHPContext {
-	server := w.server
-	if server == nil {
-		server = fallbackServer
-	}
-
 	if ctx == nil {
 		ctx = globalCtx
 	}
@@ -172,9 +161,9 @@ func newContextFromMessage(message any, rw http.ResponseWriter, ctx context.Cont
 	return &frankenPHPContext{
 		done:              make(chan any),
 		startedAt:         time.Now(),
-		server:            server,
+		server:            w.server,
 		worker:            w,
-		logger:            server.logger,
+		logger:            w.server.logger,
 		responseWriter:    rw,
 		handlerParameters: message,
 		ctx:               ctx,
diff --git a/docs/config.md b/docs/config.md
index 281f05dc75..eccca79694 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -106,11 +106,12 @@ You can also explicitly configure FrankenPHP using the [global option](https://c
 		php_ini <key> <value> # Set a php.ini directive. Can be used several times to set multiple directives.
 		worker {
 			file <path> # Sets the path to the worker script.
-			num <num> # Sets the number of PHP threads to start, defaults to 2x the number of available CPUs.
+			num <num> # Sets the number of PHP threads to start, defaults to 2x the number of available CPUs, 1 for background workers.
 			env <key> <value> # Sets an extra environment variable to the given value. Can be specified more than once for multiple environment variables.
 			watch <path> # Sets the path to watch for file changes. Can be specified more than once for multiple paths.
-			name <name> # Sets the name of the worker, used in logs and metrics. Default: absolute path of worker file
+			name <name> # Sets the name of the worker, used in logs and metrics. Must be unique among global workers. Default: absolute path of the worker file.
 			max_consecutive_failures <num> # Sets the maximum number of consecutive failures before the worker is considered unhealthy, -1 means the worker will always restart. Default: 6.
+			background # EXPERIMENTAL: marks this worker as a background (non-HTTP) worker, requiring "name" and a script calling frankenphp_worker_tick() at least once
 		}
 	}
 }
@@ -187,17 +188,18 @@ php_server [<matcher>] {
 	root <directory> # Sets the root folder to the site. Default: `root` directive.
 	split_path <delim...> # Sets the substrings for splitting the URI into two parts. The first matching substring will be used to split the "path info" from the path. The first piece is suffixed with the matching substring and will be assumed as the actual resource (CGI script) name. The second piece will be set to PATH_INFO for the script to use. Default: `.php`
 	resolve_root_symlink false # Disables resolving the `root` directory to its actual value by evaluating a symbolic link, if one exists (enabled by default).
-	name <name> # Sets the name for this server, used to attribute workers, metrics and logs. Default: the first host matcher of the enclosing route, or the first listener address.
+	name <name> # Sets the name for this server, used to attribute workers, metrics and logs. Default: the first host matcher of the enclosing route, or the first listener address. Suffixed with a number if another php_server resolves to the same name.
 	env <key> <value> # Sets an extra environment variable to the given value. Can be specified more than once for multiple environment variables.
 	file_server off # Disables the built-in file_server directive.
 	request_body_timeout <duration> # Sets an idle timeout on request body reads: a stalled (slow POST) client is cut off while a steady upload of any size succeeds. Default: 60s. Set to 0 to disable.
 	worker { # Creates a worker specific to this server. Can be specified more than once for multiple workers.
 		file <path> # Sets the path to the worker script, can be relative to the php_server root
-		num <num> # Sets the number of PHP threads to start, defaults to 2x the number of available
-		name <name> # Sets the name for the worker, used in logs and metrics. Default: absolute path of worker file. Postfixed with a number if name is already in use.
+		num <num> # Sets the number of PHP threads to start, defaults to 2x the number of available CPUs, 1 for background workers.
+		name <name> # Sets the name for the worker, used in logs and metrics. Must be unique within this php_server. In logs and metrics, the worker is reported as "<server name>:<name>". Default: absolute path of the worker file.
 		watch <path> # Sets the path to watch for file changes. Can be specified more than once for multiple paths.
 		env <key> <value> # Sets an extra environment variable to the given value. Can be specified more than once for multiple environment variables. Environment variables for this worker are also inherited from the php_server parent, but can be overwritten here.
 		match <path> # match the worker to a path pattern. Overrides try_files and can only be used in the php_server directive.
+		background # EXPERIMENTAL: marks this worker as a background (non-HTTP) worker, requiring "name" and a script calling frankenphp_worker_tick() at least once
 	}
 	worker <other_file> <num> # Can also use the short form like in the global frankenphp block.
 }
diff --git a/docs/library.md b/docs/library.md
index 7782f03182..03f0ef5898 100644
--- a/docs/library.md
+++ b/docs/library.md
@@ -60,6 +60,10 @@ err := frankenphp.Init(
 
 Workers declared without a server scope are global: they match by file path on any server. Since a global worker has no set of requests to match against, combining `WithWorkerMatcher()` with a global worker is a configuration error and `Init()` rejects it.
 
+Worker names are unique within their server (or among global workers), so two servers may each declare a worker named `queue`. The script sees the declared name, while metrics and logs report a server-scoped worker as `<server name>:<worker name>`; server names are made unique with a numeric suffix when needed. `WithWorkerName()` resolves a name within the request's server first, then among global workers.
+
+`WithWorkerBackground()` declares a [background worker](worker.md#background-workers), which runs outside the request cycle.
+
 ## Per-request options
 
 `Server.ServeHTTP()` accepts `RequestOption`s to override the server configuration for a single request, e.g. `WithRequestDocumentRoot()`, `WithRequestSplitPath()`, `WithRequestEnv()` or `WithRequestLogger()`.
diff --git a/docs/metrics.md b/docs/metrics.md
index 932707265a..8def3085da 100644
--- a/docs/metrics.md
+++ b/docs/metrics.md
@@ -19,12 +19,12 @@ When [Caddy metrics](https://caddyserver.com/docs/metrics) are enabled, FrankenP
 - `frankenphp_busy_workers{worker="[worker_name]"}`: The number of workers currently processing a request.
 - `frankenphp_worker_request_time{worker="[worker_name]"}`: The time spent processing requests by all workers.
 - `frankenphp_worker_request_count{worker="[worker_name]"}`: The number of requests processed by all workers.
-- `frankenphp_ready_workers{worker="[worker_name]"}`: The number of workers that have called `frankenphp_handle_request` at least once.
+- `frankenphp_ready_workers{worker="[worker_name]"}`: The number of workers that have reached their ready point at least once: `frankenphp_handle_request()` for HTTP workers, `frankenphp_worker_tick()` for background workers.
 - `frankenphp_worker_crashes{worker="[worker_name]"}`: The number of times a worker has unexpectedly terminated.
 - `frankenphp_worker_restarts{worker="[worker_name]"}`: The number of times a worker has been deliberately restarted.
 - `frankenphp_worker_queue_depth{worker="[worker_name]"}`: The number of queued requests.
 
-For worker metrics, the `[worker_name]` placeholder is replaced by the worker name in the Caddyfile, otherwise the absolute path of the worker file will be used.
+`[worker_name]` is the worker name from the Caddyfile, or the absolute path of the worker file when it has none. Workers of a `php_server` block are prefixed with the name of that block: `<server name>:<worker name>`. They used to be reported under their bare name unless two blocks declared the same one, so dashboards and alerts built on those series need the prefix.
 
 ## Threads State Endpoint
 
diff --git a/docs/worker.md b/docs/worker.md
index 466c7cf684..1c7aa4e147 100644
--- a/docs/worker.md
+++ b/docs/worker.md
@@ -199,6 +199,65 @@ frankenphp {
 }
 ```
 
+## Background workers
+
+This feature is experimental.
+
+A background worker runs its script in a loop outside the HTTP request cycle, on its own PHP thread. It is declared like any worker, with the `background` option; `name` is required and `num` defaults to one thread:
+
+```caddyfile
+php_server {
+	worker {
+		file jobs.php
+		num 1
+		name jobs
+		background
+	}
+}
+```
+
+The script calls `frankenphp_worker_tick()` once it is set up. The first call marks the worker ready: the server start waits for that point, and an exit before it counts as a failure. Until that call, `max_execution_time` applies as in any request, 30 seconds by default: a setup that outlives it is ended and counts as a boot failure, so raise the limit in `php_ini`, or call `set_time_limit()` in the script, when the setup legitimately takes longer. From the first call on, the run has no time limit, like the CLI. Every call returns `false` once FrankenPHP drains the worker, on shutdown, reboot or restart, and `true` otherwise. It never blocks and never hands out work: like `frankenphp_handle_request()`, it is where the runtime and the script meet. Between two calls, the script waits on the stream returned by `frankenphp_get_worker_handle()`, alone or together with its own streams. The stream becomes readable when FrankenPHP needs the script's attention, and `frankenphp_worker_tick()` consumes whatever was written on it, so the script does not read the stream itself and the stream is quiet again until the next wake-up. It is readable once right after the script starts, so a loop that services it ticks by itself and the worker is ready as soon as its loop runs.
+
+```php
+<?php
+
+$handle = frankenphp_get_worker_handle();
+
+while (frankenphp_worker_tick()) {
+    $read = [$handle]; // plus the streams the script waits on
+    $write = $except = null;
+    stream_select($read, $write, $except, 1);
+
+    doSomeWork();
+}
+
+// drained: return, FrankenPHP re-runs or stops the script
+```
+
+With an event loop, register the stream as readable and call `frankenphp_worker_tick()` from the callback. With [Revolt](https://revolt.run), the loop of amphp:
+
+```php
+<?php
+
+use Revolt\EventLoop;
+
+$handle = frankenphp_get_worker_handle();
+EventLoop::onReadable($handle, function (): void {
+    if (!frankenphp_worker_tick()) {
+        // drained: stop the loop, the script returns and FrankenPHP moves on
+        EventLoop::getDriver()->stop();
+    }
+});
+
+// the script's own watchers go here
+
+EventLoop::run();
+```
+
+The wake-up sent at start makes the callback run as soon as the loop does, which is when the worker becomes ready. The polling API of PHP 8.6 works the same way: wrap the stream in a `StreamPollHandle`, add it to a context, and call `frankenphp_worker_tick()` when it triggers.
+
+`$_SERVER['FRANKENPHP_WORKER_BACKGROUND']` holds the declared name. `FRANKENPHP_WORKER`, the variable of HTTP workers, is not set, so a script serving both roles tests which of the two is set. Background threads come on top of `num_threads` and `max_threads`; they don't autoscale, so `max_threads` is not allowed on them. From Go, declare one with `WithWorkerBackground()`.
+
 ## Superglobals behavior
 
 [PHP superglobals](https://www.php.net/manual/language.variables.superglobals.php) (`$_SERVER`, `$_ENV`, `$_GET`...)
diff --git a/frankenphp.c b/frankenphp.c
index 2378ac8ff6..6b94de6f54 100644
--- a/frankenphp.c
+++ b/frankenphp.c
@@ -13,11 +13,14 @@
 #include <php.h>
 #ifdef PHP_WIN32
 #include <config.w32.h>
+#include <win32/sockets.h>
 #else
 #include <php_config.h>
 #endif
+#include <main/php_streams.h>
 #include <php_ini.h>
 #include <php_main.h>
+#include <php_network.h>
 #include <php_output.h>
 #include <php_variables.h>
 #include <php_version.h>
@@ -28,6 +31,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #ifndef PHP_WIN32
+#include <fcntl.h>
 #include <unistd.h>
 #endif
 #if defined(__linux__)
@@ -126,6 +130,18 @@ HashTable *main_thread_env = NULL;
 
 static THREAD_LOCAL uintptr_t thread_index;
 static THREAD_LOCAL bool is_worker_thread = false;
+static THREAD_LOCAL bool is_background_worker = false;
+/* Stop socket pair of a background worker thread: [0] is the script's end,
+ * exposed via frankenphp_get_worker_handle(); [1] is transferred to the Go
+ * side, which closes it to signal a drain. */
+static THREAD_LOCAL php_socket_t worker_stop_socks[2] = {SOCK_ERR, SOCK_ERR};
+/* set by the first frankenphp_worker_tick() of the current run, the ready
+ * point of a background worker */
+static THREAD_LOCAL bool worker_ticked = false;
+/* the stream of the current run, see frankenphp_get_worker_handle(); the
+ * cache holds a ref, and the resource list of the run frees it at request
+ * shutdown, so the pointer is only reset, never released, between runs */
+static THREAD_LOCAL zend_resource *worker_handle_res = NULL;
 static THREAD_LOCAL HashTable *sandboxed_env = NULL;
 /* prepared_env holds entries from php(_server)'s `env KEY VAL`, exposed to
  * getenv() and merged into $_ENV when 'E' is in variables_order. Separate from
@@ -342,7 +358,143 @@ void frankenphp_release_thread_for_kill(force_kill_slot slot) {
 #endif
 }
 
+/* Stop channel of background workers: a socket pair. One end is exposed to
+ * the PHP script via frankenphp_get_worker_handle(), the other is handed to
+ * the Go side, which closes it on drain so the script's end reaches EOF and
+ * a stream_select() or a blocking read on it returns. A socket pair rather
+ * than a pipe because on Windows PHP's php_select() only really waits on
+ * sockets: before 8.5 it reports any other handle as always ready. */
+static void frankenphp_worker_close_sock(php_socket_t s) {
+  if (s == SOCK_ERR) {
+    return;
+  }
+  /* php_network.h maps closesocket to close outside Windows */
+  closesocket(s);
+}
+
+/* keep the pair out of processes the script may spawn: a child holding the
+ * Go side's end would keep the script's end from ever reaching EOF */
+static void frankenphp_worker_sock_no_inherit(php_socket_t s) {
+#ifdef PHP_WIN32
+  SetHandleInformation((HANDLE)s, HANDLE_FLAG_INHERIT, 0);
+#else
+  fcntl(s, F_SETFD, FD_CLOEXEC);
+#endif
+}
+
+static void frankenphp_worker_close_stop_socks(void) {
+  for (int i = 0; i < 2; i++) {
+    frankenphp_worker_close_sock(worker_stop_socks[i]);
+    worker_stop_socks[i] = SOCK_ERR;
+  }
+}
+
+static int frankenphp_worker_open_stop_pair(void) {
+#ifdef PHP_WIN32
+  /* PHP's emulation, a loopback TCP pair; it only accepts AF_INET, listens
+   * on INADDR_ANY and accepts the first peer, so check the pair is ours */
+  if (socketpair(AF_INET, SOCK_STREAM, 0, worker_stop_socks) != 0) {
+    worker_stop_socks[0] = SOCK_ERR;
+    worker_stop_socks[1] = SOCK_ERR;
+
+    return -1;
+  }
+
+  struct sockaddr_in peer = {0}, local = {0};
+  int peer_len = sizeof(peer), local_len = sizeof(local);
+  if (getpeername(worker_stop_socks[0], (struct sockaddr *)&peer, &peer_len) !=
+          0 ||
+      getsockname(worker_stop_socks[1], (struct sockaddr *)&local,
+                  &local_len) != 0 ||
+      peer.sin_port != local.sin_port ||
+      peer.sin_addr.s_addr != local.sin_addr.s_addr) {
+    frankenphp_worker_close_stop_socks();
+
+    return -1;
+  }
+#else
+#ifdef SOCK_CLOEXEC
+  int type = SOCK_STREAM | SOCK_CLOEXEC;
+#else
+  int type = SOCK_STREAM;
+#endif
+  if (socketpair(AF_UNIX, type, 0, worker_stop_socks) != 0) {
+    worker_stop_socks[0] = SOCK_ERR;
+    worker_stop_socks[1] = SOCK_ERR;
+
+    return -1;
+  }
+#endif
+  /* redundant where SOCK_CLOEXEC applied; a fork()ed child (pcntl) still
+   * inherits both ends and delays the EOF until it exits */
+  frankenphp_worker_sock_no_inherit(worker_stop_socks[0]);
+  frankenphp_worker_sock_no_inherit(worker_stop_socks[1]);
+
+  return 0;
+}
+
+/* Marks the calling thread as a background worker, opens its stop socket
+ * pair and transfers the Go side's end to the caller (clearing the TLS slot
+ * so a later recycle won't double-close it). Returns -1 if the pair could
+ * not be created. max_execution_time is disarmed after php_request_startup()
+ * re-arms it, see php_thread(). */
+intptr_t frankenphp_set_background_worker_and_get_stop_sock(void) {
+  is_background_worker = true;
+  worker_ticked = false;
+  worker_handle_res = NULL;
+
+  frankenphp_worker_close_stop_socks();
+  if (frankenphp_worker_open_stop_pair() != 0) {
+    return -1;
+  }
+
+  /* One wake-up right away, so a script that registers its handle with an
+   * event loop and runs it ticks on its own: readiness then means the loop
+   * serviced the handle once. The first frankenphp_worker_tick() consumes
+   * it. Nothing to do on failure, the script then has to tick by itself. */
+  const char wakeup = '\n';
+#ifdef MSG_NOSIGNAL
+  send(worker_stop_socks[1], &wakeup, 1, MSG_NOSIGNAL);
+#else
+  send(worker_stop_socks[1], &wakeup, 1, 0);
+#endif
+
+  intptr_t s = (intptr_t)worker_stop_socks[1];
+  worker_stop_socks[1] = SOCK_ERR;
+
+  return s;
+}
+
+/* Closes the Go side's end of a stop socket pair, which lands as EOF on the
+ * script's end so its stream_select() or blocking read returns promptly. */
+void frankenphp_worker_close_stop_sock(intptr_t s) {
+  if (s < 0) {
+    return;
+  }
+  /* Closing this end only lands as EOF on the script's end while no other
+   * process holds a copy of it, and a pcntl_fork() child inherits every
+   * descriptor of the process, including the pairs of the other threads.
+   * Shutting the write direction down sends the FIN regardless. */
+#ifdef PHP_WIN32
+  shutdown((php_socket_t)s, SD_SEND);
+#else
+  shutdown((php_socket_t)s, SHUT_WR);
+#endif
+  frankenphp_worker_close_sock((php_socket_t)s);
+}
+
 void frankenphp_update_local_thread_context(bool is_worker) {
+  /* A thread that ran a background worker can be recycled into an HTTP
+   * worker or a regular request thread: reset the bg TLS so
+   * frankenphp_get_worker_handle() rejects callers again, and release the
+   * stop socket. The streams handed out by frankenphp_get_worker_handle()
+   * do not own it and were destroyed by request shutdown. */
+  if (is_background_worker) {
+    is_background_worker = false;
+    worker_handle_res = NULL;
+    frankenphp_worker_close_stop_socks();
+  }
+
   is_worker_thread = is_worker;
 
   /* workers should keep running if the user aborts the connection */
@@ -857,6 +1009,15 @@ PHP_FUNCTION(frankenphp_handle_request) {
     RETURN_THROWS();
   }
 
+  if (is_background_worker) {
+    /* background workers never receive HTTP requests */
+    zend_throw_exception(
+        spl_ce_RuntimeException,
+        "frankenphp_handle_request() cannot be called from a background worker",
+        0);
+    RETURN_THROWS();
+  }
+
 #ifdef ZEND_MAX_EXECUTION_TIMERS
   /* Disable timeouts while waiting for a request to handle */
   zend_unset_timeout();
@@ -1017,6 +1178,129 @@ PHP_FUNCTION(frankenphp_log) {
   }
 }
 
+/* Ops of the streams returned by frankenphp_get_worker_handle(): the socket
+ * ops, except that closing a stream leaves the socket alone: it belongs to
+ * the thread, every handle of a run shares it, and it is closed at the next
+ * run setup or on thread exit. Initialized in MINIT. */
+static php_stream_ops frankenphp_worker_handle_ops;
+
+static int frankenphp_worker_handle_close(php_stream *stream,
+                                          int close_handle) {
+  (void)close_handle;
+
+  /* free the stream data only, never the shared socket */
+  return php_stream_socket_ops.close(stream, 0);
+}
+
+PHP_FUNCTION(frankenphp_get_worker_handle) {
+  ZEND_PARSE_PARAMETERS_NONE();
+
+  if (!is_background_worker) {
+    zend_throw_exception(spl_ce_RuntimeException,
+                         "frankenphp_get_worker_handle() can only be called "
+                         "from a background worker",
+                         0);
+    RETURN_THROWS();
+  }
+
+  /* the pair is opened before the script starts and closed at the next run
+   * setup or on thread exit, so a run always has one */
+  ZEND_ASSERT(worker_stop_socks[0] != SOCK_ERR);
+
+  /* One stream per run: the same resource is returned until the script
+   * closes it, so fetching the handle in a loop does not grow the resource
+   * list of a run that never ends. The stream does not own the socket (see
+   * frankenphp_worker_handle_ops), so closing it never affects a later one
+   * and the EOF of a drain reaches all. */
+  if (worker_handle_res != NULL) {
+    if (worker_handle_res->type == php_file_le_stream()) {
+      GC_ADDREF(worker_handle_res);
+      RETURN_RES(worker_handle_res);
+    }
+    /* closed by the script: drop the cache's ref */
+    zend_list_delete(worker_handle_res);
+    worker_handle_res = NULL;
+  }
+
+  php_stream *stream =
+      php_stream_sock_open_from_socket(worker_stop_socks[0], NULL);
+  if (stream == NULL) {
+    zend_throw_exception(spl_ce_RuntimeException,
+                         "failed to create a stream over the stop socket", 0);
+    RETURN_THROWS();
+  }
+
+  /* a blocking read is a valid way to park: wait without the
+   * default_socket_timeout wake-ups */
+  ((php_netstream_data_t *)stream->abstract)->timeout.tv_sec = -1;
+
+  stream->ops = &frankenphp_worker_handle_ops;
+
+  php_stream_to_zval(stream, return_value);
+  worker_handle_res = Z_RES_P(return_value);
+  GC_ADDREF(worker_handle_res);
+}
+
+/* The ready point of a background worker and its liveness check, the
+ * background analog of frankenphp_handle_request(): the first call of a run
+ * reports the worker ready, and every call returns false once FrankenPHP
+ * drains it. It never blocks and never hands out work: the script waits on
+ * its handle, alone or with its own streams, and calls this when the handle
+ * is readable. Whatever the runtime writes on the handle to wake the script
+ * up is consumed here, so the script never has to read the handle and the
+ * protocol on it stays private. */
+PHP_FUNCTION(frankenphp_worker_tick) {
+  ZEND_PARSE_PARAMETERS_NONE();
+
+  if (!is_background_worker) {
+    zend_throw_exception(spl_ce_RuntimeException,
+                         "frankenphp_worker_tick() can only be called from a "
+                         "background worker",
+                         0);
+    RETURN_THROWS();
+  }
+
+  ZEND_ASSERT(worker_stop_socks[0] != SOCK_ERR);
+
+  if (!worker_ticked) {
+    worker_ticked = true;
+    /* The bootstrap ran under max_execution_time like any request; the loop
+     * that starts now has no time limit, like the CLI. Nothing re-arms the
+     * timer past this point: php_execute_script() did so before the script
+     * started, request shutdown comes after it ended. */
+    zend_unset_timeout();
+    go_frankenphp_background_worker_ready(frankenphp_thread_index());
+  }
+
+  /* consume the wake-ups without blocking; EOF is the drain */
+  char buf[64];
+  for (;;) {
+    if (php_pollfd_for_ms(worker_stop_socks[0], PHP_POLLREADABLE, 0) <= 0) {
+      /* nothing pending, or a transient poll error: still running */
+      RETURN_TRUE;
+    }
+
+#ifdef PHP_WIN32
+    int n = recv(worker_stop_socks[0], buf, (int)sizeof(buf), 0);
+#else
+    ssize_t n = recv(worker_stop_socks[0], buf, sizeof(buf), 0);
+#endif
+    if (n == 0) {
+      /* the Go side closed its end: drained */
+      RETURN_FALSE;
+    }
+    if (n < 0) {
+      int err = php_socket_errno();
+      if (err == EINTR || PHP_IS_TRANSIENT_ERROR(err)) {
+        RETURN_TRUE;
+      }
+
+      /* a broken socket carries no drain anymore, stop the loop */
+      RETURN_FALSE;
+    }
+  }
+}
+
 /* {{{ thread-safe opcache reset */
 PHP_FUNCTION(frankenphp_opcache_reset) {
   go_schedule_opcache_reset(frankenphp_thread_index());
@@ -1075,6 +1359,10 @@ static const zend_function_entry frankenphp_test_hook_functions[] = {
 #endif
 
 PHP_MINIT_FUNCTION(frankenphp) {
+  frankenphp_worker_handle_ops = php_stream_socket_ops;
+  frankenphp_worker_handle_ops.label = "FrankenPHP worker handle";
+  frankenphp_worker_handle_ops.close = frankenphp_worker_handle_close;
+
   register_frankenphp_symbols(module_number);
 #ifndef PHP_WIN32
   /* MINIT runs once per ZTS thread — guard the atfork registration */
@@ -1598,6 +1886,15 @@ static void *php_thread(void *arg) {
   }
   zend_end_try();
 
+  /* The stop socket of a background worker is plain thread-local state that
+   * frankenphp_update_local_thread_context() only releases on recycle: close
+   * it here too so it does not outlive the thread on shutdown, reboot or an
+   * unhealthy exit. The Go side's end is closed by the Go side. */
+  if (is_background_worker) {
+    is_background_worker = false;
+    frankenphp_worker_close_stop_socks();
+  }
+
   /* Must precede ts_free_thread: that frees the TSRM storage backing
    * the slot's &EG() pointers. Clearing first means any concurrent
    * force-kill either ran before us or sees a zero slot. */
diff --git a/frankenphp.go b/frankenphp.go
index 3f7bbdf582..cbe951f822 100644
--- a/frankenphp.go
+++ b/frankenphp.go
@@ -172,26 +172,40 @@ func checkPHPConfig(config PHPConfig) error {
 	return nil
 }
 
-func calculateMaxThreads(opt *opt) (numWorkers int, _ error) {
+// calculateMaxThreads resolves num_threads and max_threads against the HTTP
+// workers and returns their thread count, plus the threads of the background
+// workers, which take no part in that budget: they come on top of it
+func calculateMaxThreads(opt *opt) (numWorkers, backgroundThreads int, _ error) {
 	maxProcs := runtime.GOMAXPROCS(0) * 2
 	maxThreadsFromWorkers := 0
 
 	for i, w := range opt.workers {
+		if w.isBackgroundWorker {
+			if w.num <= 0 {
+				// one thread unless a pool is asked for: a background
+				// worker serves no requests, so it does not scale with
+				// the CPUs like an HTTP one
+				opt.workers[i].num = 1
+			}
+			backgroundThreads += opt.workers[i].num
+
+			continue
+		}
+
 		if w.num <= 0 {
 			// https://github.com/php/frankenphp/issues/126
 			opt.workers[i].num = maxProcs
 		}
-		metrics.TotalWorkers(w.name, w.num)
 
 		numWorkers += opt.workers[i].num
 
 		if w.maxThreads > 0 {
 			if w.maxThreads < w.num {
-				return 0, fmt.Errorf("worker max_threads (%d) must be greater or equal to worker num (%d) (%q)", w.maxThreads, w.num, w.fileName)
+				return 0, 0, fmt.Errorf("worker max_threads (%d) must be greater or equal to worker num (%d) (%q)", w.maxThreads, w.num, w.fileName)
 			}
 
 			if w.maxThreads > opt.maxThreads && opt.maxThreads > 0 {
-				return 0, fmt.Errorf("worker max_threads (%d) cannot be greater than total max_threads (%d) (%q)", w.maxThreads, opt.maxThreads, w.fileName)
+				return 0, 0, fmt.Errorf("worker max_threads (%d) cannot be greater than total max_threads (%d) (%q)", w.maxThreads, opt.maxThreads, w.fileName)
 			}
 
 			maxThreadsFromWorkers += w.maxThreads - w.num
@@ -215,19 +229,19 @@ func calculateMaxThreads(opt *opt) (numWorkers int, _ error) {
 	if numThreadsIsSet && !maxThreadsIsSet {
 		opt.maxThreads = opt.numThreads
 		if opt.numThreads <= numWorkers {
-			return 0, fmt.Errorf("num_threads (%d) must be greater than the number of worker threads (%d)", opt.numThreads, numWorkers)
+			return 0, 0, fmt.Errorf("num_threads (%d) must be greater than the number of worker threads (%d)", opt.numThreads, numWorkers)
 		}
 
-		return numWorkers, nil
+		return numWorkers, backgroundThreads, nil
 	}
 
 	if maxThreadsIsSet && !numThreadsIsSet {
 		opt.numThreads = numWorkers + 1
 		if !maxThreadsIsAuto && opt.numThreads > opt.maxThreads {
-			return 0, fmt.Errorf("max_threads (%d) must be greater than the number of worker threads (%d)", opt.maxThreads, numWorkers)
+			return 0, 0, fmt.Errorf("max_threads (%d) must be greater than the number of worker threads (%d)", opt.maxThreads, numWorkers)
 		}
 
-		return numWorkers, nil
+		return numWorkers, backgroundThreads, nil
 	}
 
 	if !numThreadsIsSet {
@@ -239,19 +253,19 @@ func calculateMaxThreads(opt *opt) (numWorkers int, _ error) {
 		}
 		opt.maxThreads = opt.numThreads
 
-		return numWorkers, nil
+		return numWorkers, backgroundThreads, nil
 	}
 
 	// both num_threads and max_threads are set
 	if opt.numThreads <= numWorkers {
-		return 0, fmt.Errorf("num_threads (%d) must be greater than the number of worker threads (%d)", opt.numThreads, numWorkers)
+		return 0, 0, fmt.Errorf("num_threads (%d) must be greater than the number of worker threads (%d)", opt.numThreads, numWorkers)
 	}
 
 	if !maxThreadsIsAuto && opt.maxThreads < opt.numThreads {
-		return 0, fmt.Errorf("max_threads (%d) must be greater than or equal to num_threads (%d)", opt.maxThreads, opt.numThreads)
+		return 0, 0, fmt.Errorf("max_threads (%d) must be greater than or equal to num_threads (%d)", opt.maxThreads, opt.numThreads)
 	}
 
-	return numWorkers, nil
+	return numWorkers, backgroundThreads, nil
 }
 
 // Init starts the PHP runtime and the configured workers.
@@ -300,13 +314,15 @@ func Init(options ...Option) error {
 
 	registerServers(opt.servers)
 
-	workerThreadCount, err := calculateMaxThreads(opt)
+	workerThreadCount, backgroundThreads, err := calculateMaxThreads(opt)
 	if err != nil {
 		shutdown()
 		return err
 	}
 
-	metrics.TotalThreads(opt.numThreads)
+	// background workers run on threads of their own, on top of the budget
+	// num_threads and max_threads describe for HTTP traffic
+	metrics.TotalThreads(opt.numThreads + backgroundThreads)
 
 	config := Config()
 
@@ -324,13 +340,23 @@ func Init(options ...Option) error {
 		}
 	} else {
 		opt.numThreads = 1
+		if workerThreadCount > 1 || backgroundThreads > 0 {
+			shutdown()
+			return fmt.Errorf("%d worker threads are declared, but this PHP build is not ZTS and runs a single thread", workerThreadCount+backgroundThreads)
+		}
 
 		if globalLogger.Enabled(globalCtx, slog.LevelWarn) {
 			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, `ZTS is not enabled, only 1 thread will be available, recompile PHP using the "--enable-zts" configuration option or performance will be degraded`)
 		}
 	}
 
-	mainThread, err := initPHPThreads(opt.numThreads, opt.maxThreads, opt.phpIni)
+	maxThreads := opt.maxThreads
+	if maxThreads > 0 {
+		maxThreads += backgroundThreads
+	}
+	// in auto mode (maxThreads < 0), the main thread adds the reservation to
+	// the limit it resolves, see setAutomaticMaxThreads()
+	mainThread, err := initPHPThreads(opt.numThreads+backgroundThreads, maxThreads, backgroundThreads, opt.phpIni)
 	if err != nil {
 		shutdown()
 		return err
@@ -484,7 +510,7 @@ func go_apache_request_headers(threadIndex C.uintptr_t) (*C.go_string, C.size_t)
 		// worker mode, not handling a request
 
 		if fc.logger.Enabled(fc.ctx, slog.LevelDebug) {
-			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "apache_request_headers() called in non-HTTP context", slog.String("worker", fc.worker.name))
+			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "apache_request_headers() called in non-HTTP context", slog.String("worker", fc.worker.qualifiedName))
 		}
 
 		return nil, 0
@@ -824,8 +850,6 @@ func resetGlobals() {
 	globalCtx = context.Background()
 	globalLogger = slog.Default()
 	workers = nil
-	workersByName = nil
-	globalWorkersByPath = nil
 	servers = nil
 	watcherIsEnabled = false
 	maxIdleTime = defaultMaxIdleTime
diff --git a/frankenphp.h b/frankenphp.h
index 99ac0ab7ec..e5612ee714 100644
--- a/frankenphp.h
+++ b/frankenphp.h
@@ -201,6 +201,10 @@ size_t frankenphp_get_thread_memory_usage(uintptr_t thread_index);
 void frankenphp_force_kill_thread(force_kill_slot slot);
 void frankenphp_release_thread_for_kill(force_kill_slot slot);
 
+/* Background worker primitives. */
+intptr_t frankenphp_set_background_worker_and_get_stop_sock(void);
+void frankenphp_worker_close_stop_sock(intptr_t s);
+
 void register_extensions(zend_module_entry **m, int len);
 
 #endif
diff --git a/frankenphp.stub.php b/frankenphp.stub.php
index d6c85aa05f..e699125ea8 100644
--- a/frankenphp.stub.php
+++ b/frankenphp.stub.php
@@ -54,3 +54,31 @@ function mercure_publish(string|array $topics, string $data = '', bool $private
  * array<string, any> $context Values of the array will be converted to the corresponding Go type (if supported by FrankenPHP) and added to the context of the structured logs using https://pkg.go.dev/log/slog#Attr
  */
 function frankenphp_log(string $message, int $level = 0, array $context = []): void {}
+
+/**
+ * EXPERIMENTAL: returns the handle of the current background worker, a
+ * stream to wait on, alone or with the script's own streams: it becomes
+ * readable when FrankenPHP needs the script's attention, its drain
+ * included, and frankenphp_worker_tick() then tells whether the worker
+ * still runs. Every call of a run returns the same stream, a fresh one over
+ * the same socket once the script closed it. Only callable from inside a
+ * background worker.
+ *
+ * @return resource
+ */
+function frankenphp_get_worker_handle() {}
+
+/**
+ * EXPERIMENTAL: the ready point and liveness check of a background worker,
+ * the background analog of frankenphp_handle_request(). The first call of a
+ * run marks the worker ready: the server start waits for it, and an exit
+ * before it counts as a failure. max_execution_time applies until that
+ * call and not after. It returns false once FrankenPHP drains the
+ * worker, on shutdown, reboot or restart, so the script can leave its loop,
+ * and true otherwise. It never blocks and never hands out work: the script
+ * waits on the stream returned by frankenphp_get_worker_handle() and calls
+ * this when it is readable. Whatever FrankenPHP wrote on that stream is
+ * consumed here, the script does not have to read it. Only callable from
+ * inside a background worker.
+ */
+function frankenphp_worker_tick(): bool {}
diff --git a/frankenphp_arginfo.h b/frankenphp_arginfo.h
index 4f2707cbca..d394b57f43 100644
--- a/frankenphp_arginfo.h
+++ b/frankenphp_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 60f0d27c04f94d7b24c052e91ef294595a2bc421 */
+ * Stub hash: c7ee7c3d4fea8b3575e0a02bccf871a5d2b2977f */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_frankenphp_handle_request, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, callback, IS_CALLABLE, 0)
@@ -41,6 +41,10 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_frankenphp_log, 0, 1, IS_VOID, 0
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, context, IS_ARRAY, 0, "[]")
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_frankenphp_get_worker_handle, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+#define arginfo_frankenphp_worker_tick arginfo_frankenphp_finish_request
 
 ZEND_FUNCTION(frankenphp_handle_request);
 ZEND_FUNCTION(headers_send);
@@ -49,7 +53,8 @@ ZEND_FUNCTION(frankenphp_request_headers);
 ZEND_FUNCTION(frankenphp_response_headers);
 ZEND_FUNCTION(mercure_publish);
 ZEND_FUNCTION(frankenphp_log);
-
+ZEND_FUNCTION(frankenphp_get_worker_handle);
+ZEND_FUNCTION(frankenphp_worker_tick);
 
 static const zend_function_entry ext_functions[] = {
 	ZEND_FE(frankenphp_handle_request, arginfo_frankenphp_handle_request)
@@ -63,6 +68,8 @@ static const zend_function_entry ext_functions[] = {
 	ZEND_FALIAS(apache_response_headers, frankenphp_response_headers, arginfo_apache_response_headers)
 	ZEND_FE(mercure_publish, arginfo_mercure_publish)
 	ZEND_FE(frankenphp_log, arginfo_frankenphp_log)
+	ZEND_FE(frankenphp_get_worker_handle, arginfo_frankenphp_get_worker_handle)
+	ZEND_FE(frankenphp_worker_tick, arginfo_frankenphp_worker_tick)
 	ZEND_FE_END
 };
 
diff --git a/metrics.go b/metrics.go
index fc25816506..4011db0d41 100644
--- a/metrics.go
+++ b/metrics.go
@@ -11,7 +11,7 @@ import (
 const (
 	StopReasonCrash = iota
 	StopReasonRestart
-	StopReasonBootFailure // worker crashed before reaching frankenphp_handle_request
+	StopReasonBootFailure // worker exited before reaching its ready point: frankenphp_handle_request, or frankenphp_worker_tick for background workers
 )
 
 type StopReason int
@@ -144,7 +144,7 @@ func (m *PrometheusMetrics) StopWorker(name string, reason StopReason) {
 
 	m.totalWorkers.WithLabelValues(name).Dec()
 
-	// only decrement readyWorkers if the worker actually reached frankenphp_handle_request
+	// only decrement readyWorkers if the worker actually reached its ready point
 	if reason != StopReasonBootFailure {
 		m.readyWorkers.WithLabelValues(name).Dec()
 	}
@@ -177,7 +177,7 @@ func (m *PrometheusMetrics) TotalWorkers(string, int) {
 		m.readyWorkers = prometheus.NewGaugeVec(prometheus.GaugeOpts{
 			Namespace: ns,
 			Name:      "ready_workers",
-			Help:      "Running workers that have successfully called frankenphp_handle_request at least once",
+			Help:      "Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers",
 		}, basicLabels)
 		m.mustRegister(m.readyWorkers)
 	}
diff --git a/metrics_test.go b/metrics_test.go
index 846a926569..7d721f0189 100644
--- a/metrics_test.go
+++ b/metrics_test.go
@@ -185,7 +185,7 @@ func TestPrometheusMetrics_TestStopReasonCrash(t *testing.T) {
 			name: "Testing ReadyWorkers",
 			c:    m.readyWorkers,
 			metadata: `
-				# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
+				# HELP frankenphp_ready_workers Running workers that have reached their ready point at least once: frankenphp_handle_request for HTTP workers, frankenphp_worker_tick for background workers
 				# TYPE frankenphp_ready_workers gauge
 			`,
 			expect: `
diff --git a/options.go b/options.go
index e1eaeb7b55..930eb5d182 100644
--- a/options.go
+++ b/options.go
@@ -57,6 +57,7 @@ type workerOpt struct {
 	onServerStartup        func()
 	onServerShutdown       func()
 	server                 *Server
+	isBackgroundWorker     bool
 }
 
 // WithContext sets the main context to use.
@@ -239,6 +240,20 @@ func WithWorkerServerScope(s *Server) WorkerOption {
 	}
 }
 
+// EXPERIMENTAL: WithWorkerBackground marks this worker as a background
+// (non-HTTP) worker. Background workers run outside the request cycle:
+// they share the PHP runtime with HTTP threads but never receive HTTP
+// requests. The script can park on the stream returned by
+// frankenphp_get_worker_handle(), which reaches EOF when FrankenPHP
+// drains the worker, to exit gracefully on shutdown or restart.
+func WithWorkerBackground() WorkerOption {
+	return func(w *workerOpt) error {
+		w.isBackgroundWorker = true
+
+		return nil
+	}
+}
+
 // WithWorkerMaxFailures sets the maximum number of consecutive failures before panicking
 func WithWorkerMaxFailures(maxFailures int) WorkerOption {
 	return func(w *workerOpt) error {
diff --git a/phpmainthread.go b/phpmainthread.go
index 5e19c0fc75..db48197b22 100644
--- a/phpmainthread.go
+++ b/phpmainthread.go
@@ -20,12 +20,16 @@ import (
 // represents the main PHP thread
 // the thread needs to keep running as long as all other threads are running
 type phpMainThread struct {
-	state       *state.ThreadState
-	done        chan struct{}
-	numThreads  int
-	maxThreads  int
-	phpIni      map[string]string
-	isRebooting atomic.Bool
+	state      *state.ThreadState
+	done       chan struct{}
+	numThreads int
+	maxThreads int
+	// backgroundThreads is the part of numThreads and maxThreads that
+	// background workers reserve: it takes no part in the HTTP budget,
+	// see calculateMaxThreads()
+	backgroundThreads int
+	phpIni            map[string]string
+	isRebooting       atomic.Bool
 }
 
 var (
@@ -41,13 +45,14 @@ var (
 // initPHPThreads starts the main PHP thread,
 // a fixed number of inactive PHP threads
 // and reserves a fixed number of possible PHP threads
-func initPHPThreads(numThreads int, numMaxThreads int, phpIni map[string]string) (*phpMainThread, error) {
+func initPHPThreads(numThreads int, numMaxThreads int, backgroundThreads int, phpIni map[string]string) (*phpMainThread, error) {
 	mainThread = &phpMainThread{
-		state:      state.NewThreadState(),
-		done:       make(chan struct{}),
-		numThreads: numThreads,
-		maxThreads: numMaxThreads,
-		phpIni:     phpIni,
+		state:             state.NewThreadState(),
+		done:              make(chan struct{}),
+		numThreads:        numThreads,
+		maxThreads:        numMaxThreads,
+		backgroundThreads: backgroundThreads,
+		phpIni:            phpIni,
 	}
 
 	// initialize the first thread
@@ -161,6 +166,10 @@ func (mainThread *phpMainThread) rebootAllThreads() bool {
 
 	for _, thread := range rebootingThreads {
 		rebootWg.Go(func() {
+			// wake up handlers parked in a blocking C call (background
+			// workers' stream_select on the stop socket) so they can yield
+			// for the reboot without waiting for the force-kill below
+			thread.handler.drain()
 			close(thread.drainChan)
 			if thread.state.WaitForStateWithTimeout(rebootGracePeriod, state.YieldingForReboot) {
 				return
@@ -259,18 +268,21 @@ func go_frankenphp_main_thread_is_ready() {
 // max_threads = auto
 // setAutomaticMaxThreads estimates the amount of threads based on php.ini and system memory_limit
 // If unable to get the system's memory limit, simply double num_threads
+// The estimate is an HTTP one, like an explicit max_threads: the threads
+// background workers reserve are added to it rather than taken out of it
 func (mainThread *phpMainThread) setAutomaticMaxThreads() {
 	if mainThread.maxThreads >= 0 {
 		return
 	}
+	httpThreads := mainThread.numThreads - mainThread.backgroundThreads
 	perThreadMemoryLimit := int64(C.frankenphp_get_current_memory_limit())
 	totalSysMemory := memory.TotalSysMemory()
 	if perThreadMemoryLimit <= 0 || totalSysMemory == 0 {
-		mainThread.maxThreads = mainThread.numThreads * 2
+		mainThread.maxThreads = httpThreads*2 + mainThread.backgroundThreads
 		return
 	}
 	maxAllowedThreads := totalSysMemory / uint64(perThreadMemoryLimit)
-	mainThread.maxThreads = int(maxAllowedThreads)
+	mainThread.maxThreads = int(maxAllowedThreads) + mainThread.backgroundThreads
 
 	if globalLogger.Enabled(globalCtx, slog.LevelDebug) {
 		globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "Automatic thread limit", slog.Int("perThreadMemoryLimitMB", int(perThreadMemoryLimit/1024/1024)), slog.Int("maxThreads", mainThread.maxThreads))
diff --git a/phpmainthread_test.go b/phpmainthread_test.go
index 3ae65e68b9..8d78e25e74 100644
--- a/phpmainthread_test.go
+++ b/phpmainthread_test.go
@@ -26,7 +26,7 @@ func setupGlobals(t *testing.T) {
 }
 
 func TestStartAndStopTheMainThreadWithOneInactiveThread(t *testing.T) {
-	_, err := initPHPThreads(1, 1, nil) // boot 1 thread
+	_, err := initPHPThreads(1, 1, 0, nil) // boot 1 thread
 	assert.NoError(t, err)
 
 	assert.Len(t, phpThreads, 1)
@@ -41,7 +41,7 @@ func TestStartAndStopTheMainThreadWithOneInactiveThread(t *testing.T) {
 func TestTransitionRegularThreadToWorkerThread(t *testing.T) {
 	setupGlobals(t)
 
-	_, err := initPHPThreads(1, 1, nil)
+	_, err := initPHPThreads(1, 1, 0, nil)
 	assert.NoError(t, err)
 
 	// transition to regular thread
@@ -66,7 +66,7 @@ func TestTransitionRegularThreadToWorkerThread(t *testing.T) {
 func TestTransitionAThreadBetween2DifferentWorkers(t *testing.T) {
 	setupGlobals(t)
 
-	_, err := initPHPThreads(1, 1, nil)
+	_, err := initPHPThreads(1, 1, 0, nil)
 	assert.NoError(t, err)
 	firstWorker := getDummyWorker(t, "transition-worker-1.php")
 	secondWorker := getDummyWorker(t, "transition-worker-2.php")
@@ -228,7 +228,7 @@ func TestQueuedRequestSurvivesReload(t *testing.T) {
 func TestFinishBootingAWorkerScript(t *testing.T) {
 	setupGlobals(t)
 
-	_, err := initPHPThreads(1, 1, nil)
+	_, err := initPHPThreads(1, 1, 0, nil)
 	assert.NoError(t, err)
 
 	// boot the worker
@@ -252,28 +252,24 @@ func TestFinishBootingAWorkerScript(t *testing.T) {
 
 func TestReturnAnErrorIf2WorkersHaveTheSameFileName(t *testing.T) {
 	resetGlobals()
-	workers = []*worker{}
-	workersByName = map[string]*worker{}
-	globalWorkersByPath = map[string]*worker{}
-	w, err1 := newWorker(workerOpt{fileName: testDataPath + "/index.php"})
-	assert.NoError(t, err1)
-	workers = append(workers, w)
-	workersByName[w.name] = w
-	globalWorkersByPath[w.fileName] = w
-	_, err2 := newWorker(workerOpt{fileName: testDataPath + "/index.php"})
-	assert.Error(t, err2, "two workers cannot have the same filename")
+	fallbackServer.resetWorkers()
+	w1, err := newWorker(workerOpt{fileName: testDataPath + "/index.php"})
+	assert.NoError(t, err)
+	assert.NoError(t, fallbackServer.addWorker(w1))
+	w2, err := newWorker(workerOpt{fileName: testDataPath + "/index.php", name: "other"})
+	assert.NoError(t, err)
+	assert.ErrorContains(t, fallbackServer.addWorker(w2), "two global workers cannot have the same filename")
 }
 
 func TestReturnAnErrorIf2ModuleWorkersHaveTheSameName(t *testing.T) {
 	resetGlobals()
-	workers = []*worker{}
-	workersByName = map[string]*worker{}
-	w, err1 := newWorker(workerOpt{fileName: testDataPath + "/index.php", name: "workername"})
-	assert.NoError(t, err1)
-	workers = append(workers, w)
-	workersByName[w.name] = w
-	_, err2 := newWorker(workerOpt{fileName: testDataPath + "/hello.php", name: "workername"})
-	assert.Error(t, err2, "two workers cannot have the same name")
+	fallbackServer.resetWorkers()
+	w1, err := newWorker(workerOpt{fileName: testDataPath + "/index.php", name: "workername"})
+	assert.NoError(t, err)
+	assert.NoError(t, fallbackServer.addWorker(w1))
+	w2, err := newWorker(workerOpt{fileName: testDataPath + "/hello.php", name: "workername"})
+	assert.NoError(t, err)
+	assert.ErrorContains(t, fallbackServer.addWorker(w2), "two global workers cannot have the same name")
 }
 
 func getDummyWorker(t *testing.T, fileName string) *worker {
@@ -315,9 +311,9 @@ func allPossibleTransitions(worker1Path string, worker2Path string) []func(*phpT
 				thread.boot()
 			}
 		},
-		func(thread *phpThread) { convertToWorkerThread(thread, globalWorkersByPath[worker1Path]) },
+		func(thread *phpThread) { convertToWorkerThread(thread, fallbackServer.workersByPath[worker1Path]) },
 		convertToInactiveThread,
-		func(thread *phpThread) { convertToWorkerThread(thread, globalWorkersByPath[worker2Path]) },
+		func(thread *phpThread) { convertToWorkerThread(thread, fallbackServer.workersByPath[worker2Path]) },
 		convertToInactiveThread,
 	}
 }
@@ -371,7 +367,7 @@ func TestCorrectThreadCalculation(t *testing.T) {
 func testThreadCalculation(t *testing.T, expectedNumThreads int, expectedMaxThreads int, o *opt) {
 	t.Helper()
 
-	_, err := calculateMaxThreads(o)
+	_, _, err := calculateMaxThreads(o)
 	assert.NoError(t, err, "no error should be returned")
 	assert.Equal(t, expectedNumThreads, o.numThreads, "num_threads must be correct")
 	assert.Equal(t, expectedMaxThreads, o.maxThreads, "max_threads must be correct")
@@ -380,7 +376,7 @@ func testThreadCalculation(t *testing.T, expectedNumThreads int, expectedMaxThre
 func testThreadCalculationError(t *testing.T, o *opt) {
 	t.Helper()
 
-	_, err := calculateMaxThreads(o)
+	_, _, err := calculateMaxThreads(o)
 	assert.Error(t, err, "configuration must error")
 }
 
@@ -389,7 +385,8 @@ func TestContextAndLoggerMustNotBeNil(t *testing.T) {
 	assert.NotNil(t, log, "logger is defined if all threads are inactive")
 	assert.NotNil(t, ctx, "context is defined if all threads are inactive")
 
-	fc := newContextFromMessage(nil, nil, nil, &worker{})
+	// a worker always belongs to a server, see newWorker()
+	fc := newContextFromMessage(nil, nil, nil, &worker{server: fallbackServer})
 	assert.NotNil(t, fc.logger, "logger is defined for message context")
 	assert.NotNil(t, fc.ctx, "context is defined for message context")
 
@@ -398,7 +395,7 @@ func TestContextAndLoggerMustNotBeNil(t *testing.T) {
 	assert.NotNil(t, fc.logger, "logger is defined for request context")
 	assert.NotNil(t, fc.ctx, "context is defined for request context")
 
-	fc, _ = newWorkerDummyContext(&worker{})
+	fc, _ = newWorkerDummyContext(&worker{server: fallbackServer})
 	assert.NotNil(t, fc.logger, "logger is defined for worker dummy context")
 	assert.NotNil(t, fc.ctx, "context is defined for worker dummy context")
 }
diff --git a/phpthread.go b/phpthread.go
index 39ee24b5d4..4165da482a 100644
--- a/phpthread.go
+++ b/phpthread.go
@@ -39,11 +39,10 @@ type threadHandler interface {
 	beforeScriptExecution() string
 	afterScriptExecution(exitStatus int)
 	frankenPHPContext() *frankenPHPContext
-	// drain is a hook called by drainWorkerThreads right before drainChan is
-	// closed. Handlers that need to wake up a thread parked in a blocking C
-	// call (e.g. by closing a stop pipe) plug their signal in here. All
-	// current handlers are no-ops; this is the seam later handler types use
-	// without having to modify drainWorkerThreads.
+	// drain is a hook called right before drainChan is closed on shutdown
+	// and reboot. Handlers that need to wake up a thread parked in a
+	// blocking C call (background workers' stream_select on the stop socket)
+	// plug their signal in here; the other handlers are no-ops.
 	drain()
 }
 
@@ -119,6 +118,9 @@ func (thread *phpThread) shutdown() {
 		return
 	}
 
+	// wake up handlers parked in a blocking C call (background workers'
+	// stream_select on the stop socket); no-op for the other handlers
+	thread.handler.drain()
 	close(thread.drainChan)
 
 	// Arm force-kill after the grace period to wake any thread stuck in
@@ -157,6 +159,9 @@ func (thread *phpThread) setHandler(handler threadHandler) {
 		return
 	}
 
+	// wake up a handler parked in a blocking C call (background workers'
+	// stream_select on the stop socket) so it can yield for the transition
+	thread.handler.drain()
 	close(thread.drainChan)
 
 	thread.state.WaitFor(state.TransitionInProgress)
diff --git a/requestoptions.go b/requestoptions.go
index 962727562f..00c5892f05 100644
--- a/requestoptions.go
+++ b/requestoptions.go
@@ -2,6 +2,7 @@ package frankenphp
 
 import (
 	"errors"
+	"fmt"
 	"log/slog"
 	"net/http"
 	"path/filepath"
@@ -206,12 +207,22 @@ func WithRequestBodyTimeout(timeout time.Duration) RequestOption {
 }
 
 // WithWorkerName sets the worker that should handle the request
+// the name is resolved among the workers of the request's server first, then among global workers
 func WithWorkerName(name string) RequestOption {
 	return func(o *frankenPHPContext) error {
-		if name != "" {
-			o.worker = workersByName[name]
+		if name == "" {
+			return nil
 		}
 
+		w := o.server.workersByName[name]
+		if w == nil {
+			w = fallbackServer.workersByName[name]
+		}
+		if w != nil && w.isBackgroundWorker {
+			return fmt.Errorf("background worker %q cannot handle requests", name)
+		}
+		o.worker = w
+
 		return nil
 	}
 }
diff --git a/scaling.go b/scaling.go
index dd21a7e37c..c26465efbd 100644
--- a/scaling.go
+++ b/scaling.go
@@ -96,7 +96,7 @@ func scaleWorkerThread(worker *worker, done chan struct{}, mstate *state.ThreadS
 	thread, err := addWorkerThread(worker)
 	if err != nil {
 		if globalLogger.Enabled(globalCtx, slog.LevelWarn) {
-			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "could not increase max_threads, consider raising this limit", slog.String("worker", worker.name), slog.Any("error", err))
+			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "could not increase max_threads, consider raising this limit", slog.String("worker", worker.qualifiedName), slog.Any("error", err))
 		}
 
 		return
@@ -105,7 +105,7 @@ func scaleWorkerThread(worker *worker, done chan struct{}, mstate *state.ThreadS
 	autoScaledThreads = append(autoScaledThreads, thread)
 
 	if globalLogger.Enabled(globalCtx, slog.LevelInfo) {
-		globalLogger.LogAttrs(globalCtx, slog.LevelInfo, "upscaling worker thread", slog.String("worker", worker.name), slog.Int("thread", thread.threadIndex), slog.Int("num_threads", len(autoScaledThreads)))
+		globalLogger.LogAttrs(globalCtx, slog.LevelInfo, "upscaling worker thread", slog.String("worker", worker.qualifiedName), slog.Int("thread", thread.threadIndex), slog.Int("num_threads", len(autoScaledThreads)))
 	}
 }
 
@@ -177,7 +177,7 @@ func startUpscalingThreads(maxScaledThreads int, scale chan *frankenPHPContext,
 			// check for max worker threads here again in case requests overflowed while waiting
 			if fc.worker.isAtThreadLimit() {
 				if globalLogger.Enabled(globalCtx, slog.LevelInfo) {
-					globalLogger.LogAttrs(globalCtx, slog.LevelInfo, "cannot scale worker thread, max threads reached for worker", slog.String("worker", fc.worker.name))
+					globalLogger.LogAttrs(globalCtx, slog.LevelInfo, "cannot scale worker thread, max threads reached for worker", slog.String("worker", fc.worker.qualifiedName))
 				}
 
 				continue
diff --git a/scaling_test.go b/scaling_test.go
index d2784a8eeb..a702ea8241 100644
--- a/scaling_test.go
+++ b/scaling_test.go
@@ -48,7 +48,7 @@ func TestScaleAWorkerThreadUpAndDown(t *testing.T) {
 	autoScaledThread := phpThreads[2]
 
 	// scale up
-	scaleWorkerThread(globalWorkersByPath[workerPath], mainThread.done, mainThread.state)
+	scaleWorkerThread(fallbackServer.workersByPath[workerPath], mainThread.done, mainThread.state)
 	assert.Equal(t, state.Ready, autoScaledThread.state.Get())
 
 	// on down-scale, the thread will be marked as inactive
diff --git a/server.go b/server.go
index 8274f23c54..70f23a335f 100644
--- a/server.go
+++ b/server.go
@@ -20,7 +20,7 @@ type Server struct {
 	root                      string
 	splitPath                 []string
 	env                       PreparedEnv
-	workers                   []*worker
+	workersByName             map[string]*worker
 	workersByPath             map[string]*worker
 	workersWithRequestMatcher []*worker
 
@@ -35,13 +35,15 @@ var (
 	fallbackServer = newFallbackServer()
 )
 
+// newFallbackServer creates the server of requests and workers that are not
+// scoped to one, so a lookup is always a lookup in a server
 func newFallbackServer() *Server {
 	s := &Server{
-		idx:           -1,
-		workersByPath: make(map[string]*worker),
-		env:           make(map[string]string),
-		logger:        globalLogger,
+		idx:    -1,
+		env:    make(map[string]string),
+		logger: globalLogger,
 	}
+	s.resetWorkers()
 
 	return s
 }
@@ -54,12 +56,36 @@ func registerServers(newServers []*Server) {
 	fallbackServer.logger = globalLogger
 	fallbackServer.resetWorkers()
 
+	// several servers may resolve to the same name (e.g. the same host), but
+	// the name qualifies worker names in metrics and logs, so it must be
+	// unique: the first server keeps a name, the next ones get a numeric
+	// suffix that never takes a name another server configured
+	configured := make(map[string]struct{}, len(servers))
+	for _, s := range servers {
+		if s.configuredName != "" {
+			configured[s.configuredName] = struct{}{}
+		}
+	}
+
+	taken := make(map[string]struct{}, len(servers))
 	for i, s := range servers {
 		s.idx = i
-		s.name = s.configuredName
-		if s.name == "" {
-			s.name = "server_" + strconv.Itoa(i)
+		name := s.configuredName
+		if name == "" {
+			name = "server_" + strconv.Itoa(i)
 		}
+
+		for base, n := name, 1; ; n++ {
+			_, isTaken := taken[name]
+			_, isConfigured := configured[name]
+			if !isTaken && (!isConfigured || name == s.configuredName) {
+				break
+			}
+			name = base + "_" + strconv.Itoa(n)
+		}
+		taken[name] = struct{}{}
+
+		s.name = name
 		s.resetWorkers()
 	}
 }
@@ -83,7 +109,7 @@ func unregisterServers() {
 
 // resetWorkers drops the workers of a previous run; initWorkers() adds them back
 func (s *Server) resetWorkers() {
-	s.workers = nil
+	s.workersByName = make(map[string]*worker)
 	s.workersByPath = make(map[string]*worker)
 	s.workersWithRequestMatcher = nil
 }
@@ -99,9 +125,9 @@ func NewServer(root string, options ...ServerOption) (*Server, error) {
 	}
 
 	s := &Server{
-		root:          root,
-		workersByPath: make(map[string]*worker),
+		root: root,
 	}
+	s.resetWorkers()
 
 	for _, option := range options {
 		if err := option(s); err != nil {
@@ -125,20 +151,37 @@ func NewServer(root string, options ...ServerOption) (*Server, error) {
 }
 
 // Name returns the human-readable name of the server.
-// It is empty until registration if none was passed to NewServer().
+// It is empty until registration if none was passed to NewServer(), and gets
+// a numeric suffix if another registered server has the same name.
 func (s *Server) Name() string {
 	return s.name
 }
 
+// addWorker registers a worker scoped to this server
 func (s *Server) addWorker(w *worker) error {
-	s.workers = append(s.workers, w)
+	// the fallback server holds the workers declared without a scope
+	scope := "two workers in a server"
+	if s == fallbackServer {
+		scope = "two global workers"
+	}
+
+	if s.workersByName[w.name] != nil {
+		return fmt.Errorf("%s cannot have the same name: %q", scope, w.name)
+	}
+	s.workersByName[w.name] = w
+
+	// background workers never serve requests, so they are not matched at all
+	if w.isBackgroundWorker {
+		return nil
+	}
+
 	if w.matchRequest != nil {
 		s.workersWithRequestMatcher = append(s.workersWithRequestMatcher, w)
 		return nil
 	}
 
-	if _, exists := s.workersByPath[w.fileName]; exists {
-		return fmt.Errorf("two workers in a server cannot have the same filename: %q", w.fileName)
+	if s.workersByPath[w.fileName] != nil {
+		return fmt.Errorf("%s cannot have the same filename: %q", scope, w.fileName)
 	}
 	s.workersByPath[w.fileName] = w
 
diff --git a/server_test.go b/server_test.go
index f297db7c29..4bd078040c 100644
--- a/server_test.go
+++ b/server_test.go
@@ -59,12 +59,59 @@ func TestServer(t *testing.T) {
 	t.Run("name", func(t *testing.T) {
 		named, _ := frankenphp.NewServer(testDataDir, frankenphp.WithServerName("api"))
 		unnamed, _ := frankenphp.NewServer(testDataDir)
+		alsoNamed, _ := frankenphp.NewServer(testDataDir, frankenphp.WithServerName("api"))
+		explicit, _ := frankenphp.NewServer(testDataDir, frankenphp.WithServerName("api_1"))
 
-		initServers(t, frankenphp.WithServer(named), frankenphp.WithServer(unnamed))
+		initServers(t, frankenphp.WithServer(named), frankenphp.WithServer(unnamed), frankenphp.WithServer(alsoNamed), frankenphp.WithServer(explicit))
 
 		assert.Equal(t, "api", named.Name())
 		// an empty name defaults to the server index at registration
 		assert.Equal(t, "server_1", unnamed.Name())
+		// names qualify worker names in metrics, so they are made unique, and
+		// a generated suffix never takes a name another server configured
+		assert.Equal(t, "api_2", alsoNamed.Name())
+		assert.Equal(t, "api_1", explicit.Name())
+	})
+
+	t.Run("same_worker_name_in_two_servers", func(t *testing.T) {
+		server1, _ := frankenphp.NewServer(testDataDir, frankenphp.WithServerName("one"))
+		server2, _ := frankenphp.NewServer(testDataDir, frankenphp.WithServerName("two"))
+		initServers(
+			t,
+			frankenphp.WithServer(server1),
+			frankenphp.WithServer(server2),
+			frankenphp.WithWorkers("counter", testDataDir+"worker-with-counter.php", 1, frankenphp.WithWorkerServerScope(server1)),
+			frankenphp.WithWorkers("counter", testDataDir+"worker-with-counter.php", 1, frankenphp.WithWorkerServerScope(server2)),
+		)
+
+		// WithWorkerName resolves the name within the request's server
+		byName := func(server *frankenphp.Server) string {
+			t.Helper()
+			w := httptest.NewRecorder()
+			req := httptest.NewRequest(http.MethodGet, "http://example.com/index.php", nil)
+			require.NoError(t, server.ServeHTTP(w, req, frankenphp.WithWorkerName("counter")))
+			body, err := io.ReadAll(w.Result().Body)
+			require.NoError(t, err)
+
+			return string(body)
+		}
+
+		assert.Equal(t, "requests:1", byName(server1))
+		assert.Equal(t, "requests:1", byName(server2), "server 2 must get its own worker, not server 1's")
+		assert.Equal(t, "requests:2", byName(server1))
+	})
+
+	t.Run("error_on_duplicate_worker_names", func(t *testing.T) {
+		t.Cleanup(frankenphp.Shutdown)
+
+		server, _ := frankenphp.NewServer(testDataDir)
+		err := frankenphp.Init(
+			frankenphp.WithServer(server),
+			frankenphp.WithWorkers("same", testDataDir+"worker-with-counter.php", 1, frankenphp.WithWorkerServerScope(server)),
+			frankenphp.WithWorkers("same", testDataDir+"index.php", 1, frankenphp.WithWorkerServerScope(server)),
+		)
+
+		assert.ErrorContains(t, err, "two workers in a server cannot have the same name")
 	})
 
 	t.Run("root", func(t *testing.T) {
diff --git a/testdata/_executor.php b/testdata/_executor.php
index 61a5319f11..31b87c79cb 100644
--- a/testdata/_executor.php
+++ b/testdata/_executor.php
@@ -1,7 +1,7 @@
 <?php
 
 $fn = require $_SERVER['SCRIPT_FILENAME'];
-if ('1' !== ($_SERVER['FRANKENPHP_WORKER'] ?? null)) {
+if (!isset($_SERVER['FRANKENPHP_WORKER'])) {
     $fn();
     exit(0);
 }
diff --git a/testdata/bgworker/basic.php b/testdata/bgworker/basic.php
new file mode 100644
index 0000000000..9565cef551
--- /dev/null
+++ b/testdata/bgworker/basic.php
@@ -0,0 +1,20 @@
+<?php
+
+// Long-lived background worker. FrankenPHP disables max_execution_time for
+// background runs, see TestBackgroundWorkerParkingIsNotInterrupted, so the
+// script does not have to.
+
+// Touch the sentinel so the test can confirm the worker actually ran.
+if (!empty($_SERVER['BG_SENTINEL'])) {
+    @touch($_SERVER['BG_SENTINEL']);
+}
+
+// Ready, then park on the handle until FrankenPHP drains us: the drain
+// closes the other end of the socket pair, which lands as EOF here and
+// makes the next tick return false.
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/count.php b/testdata/bgworker/count.php
new file mode 100644
index 0000000000..9c654699ba
--- /dev/null
+++ b/testdata/bgworker/count.php
@@ -0,0 +1,14 @@
+<?php
+
+// Long-lived bg worker appending a line to $_SERVER['BG_COUNT_FILE'] on
+// every run, so a test can count how many times it was (re)started.
+set_time_limit(0);
+if (!empty($_SERVER['BG_COUNT_FILE'])) {
+    @file_put_contents($_SERVER['BG_COUNT_FILE'], "run\n", FILE_APPEND);
+}
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/crash-after-ready.php b/testdata/bgworker/crash-after-ready.php
new file mode 100644
index 0000000000..4d997c17f5
--- /dev/null
+++ b/testdata/bgworker/crash-after-ready.php
@@ -0,0 +1,9 @@
+<?php
+
+// Reaches the ready point, the first frankenphp_worker_tick(), then exits
+// non-zero: a crash after readiness restarts with the backoff and does not
+// count toward max_consecutive_failures. Runs are counted in BG_COUNT_FILE.
+set_time_limit(0);
+file_put_contents($_SERVER['BG_COUNT_FILE'], "run\n", FILE_APPEND);
+frankenphp_worker_tick();
+exit(1);
diff --git a/testdata/bgworker/crash.php b/testdata/bgworker/crash.php
new file mode 100644
index 0000000000..96d224bd9f
--- /dev/null
+++ b/testdata/bgworker/crash.php
@@ -0,0 +1,30 @@
+<?php
+
+// Crash-and-recover fixture. On the first boot (no marker), creates the
+// marker and exit(1) so the bg worker thread observes a non-zero exit
+// status. On the second boot (marker present), touches a "restarted"
+// sentinel and parks on its handle. The test asserts the restarted
+// sentinel appears, proving the crash-restart loop ran.
+set_time_limit(0);
+
+$marker = $_SERVER['BG_CRASH_MARKER'] ?? '';
+$restarted = $_SERVER['BG_RESTARTED_SENTINEL'] ?? '';
+
+if ($marker === '' || $restarted === '') {
+    // Misconfigured: don't loop forever on a missing env.
+    exit(2);
+}
+
+if (!file_exists($marker)) {
+    file_put_contents($marker, '1');
+    exit(1);
+}
+
+@touch($restarted);
+
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/early-return.php b/testdata/bgworker/early-return.php
new file mode 100644
index 0000000000..3162273799
--- /dev/null
+++ b/testdata/bgworker/early-return.php
@@ -0,0 +1,5 @@
+<?php
+
+// Broken background worker: returns immediately without ever calling
+// frankenphp_worker_tick(). Without a guard this would respawn in a tight
+// loop; the guard treats it as a boot failure instead.
diff --git a/testdata/bgworker/fail-then-succeed.php b/testdata/bgworker/fail-then-succeed.php
new file mode 100644
index 0000000000..71d82199a7
--- /dev/null
+++ b/testdata/bgworker/fail-then-succeed.php
@@ -0,0 +1,17 @@
+<?php
+
+// Crashes on its first BG_FAIL_UNTIL boots, then parks: the boot-failure
+// backoff up to a success. Boots are counted in BG_COUNT_FILE.
+set_time_limit(0);
+$count = (int) @file_get_contents($_SERVER['BG_COUNT_FILE']) + 1;
+file_put_contents($_SERVER['BG_COUNT_FILE'], (string) $count);
+if ($count <= (int) $_SERVER['BG_FAIL_UNTIL']) {
+    exit(1);
+}
+@touch($_SERVER['BG_SENTINEL']);
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/fetch-no-tick.php b/testdata/bgworker/fetch-no-tick.php
new file mode 100644
index 0000000000..a8d5ec5770
--- /dev/null
+++ b/testdata/bgworker/fetch-no-tick.php
@@ -0,0 +1,7 @@
+<?php
+
+// Broken background worker: fetches its handle but returns without ever
+// calling frankenphp_worker_tick(). Fetching is not the ready point, the
+// tick is, so this counts as a boot failure like early-return.php.
+set_time_limit(0);
+$stream = frankenphp_get_worker_handle();
diff --git a/testdata/bgworker/flag.php b/testdata/bgworker/flag.php
new file mode 100644
index 0000000000..24eb70a85f
--- /dev/null
+++ b/testdata/bgworker/flag.php
@@ -0,0 +1,15 @@
+<?php
+
+// Bg worker writing the two worker variables as it sees them, so the test
+// can assert their exact values, then parking.
+set_time_limit(0);
+file_put_contents($_SERVER['BG_SENTINEL'], var_export([
+    'worker' => $_SERVER['FRANKENPHP_WORKER'] ?? 'unset',
+    'background' => $_SERVER['FRANKENPHP_WORKER_BACKGROUND'] ?? 'unset',
+], true));
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/loop.php b/testdata/bgworker/loop.php
new file mode 100644
index 0000000000..f7541eb7dd
--- /dev/null
+++ b/testdata/bgworker/loop.php
@@ -0,0 +1,15 @@
+<?php
+
+// Long-lived bg worker that never ticks on its own initiative: its loop only
+// calls frankenphp_worker_tick() once the handle is readable, the shape of a
+// script driven by an event loop. The wake-up FrankenPHP sends at start is
+// what makes it ready.
+if (!empty($_SERVER['BG_SENTINEL'])) {
+    @touch($_SERVER['BG_SENTINEL']);
+}
+$handle = frankenphp_get_worker_handle();
+do {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+} while (frankenphp_worker_tick());
diff --git a/testdata/bgworker/named.php b/testdata/bgworker/named.php
new file mode 100644
index 0000000000..70bbfaa88c
--- /dev/null
+++ b/testdata/bgworker/named.php
@@ -0,0 +1,20 @@
+<?php
+
+// Long-lived bg worker that touches a per-name sentinel under
+// $_SERVER['BG_SENTINEL_DIR'] so tests can confirm the right instance
+// ran. The bg worker's $_SERVER['FRANKENPHP_WORKER_BACKGROUND'] value is
+// the declared name, so the same fixture serves multiple distinct names
+// across scopes.
+set_time_limit(0);
+
+$name = $_SERVER['FRANKENPHP_WORKER_BACKGROUND'] ?? 'unknown';
+if (!empty($_SERVER['BG_SENTINEL_DIR'])) {
+    @touch($_SERVER['BG_SENTINEL_DIR'] . DIRECTORY_SEPARATOR . $name);
+}
+
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/no-time-limit.php b/testdata/bgworker/no-time-limit.php
new file mode 100644
index 0000000000..d4228e6ef0
--- /dev/null
+++ b/testdata/bgworker/no-time-limit.php
@@ -0,0 +1,11 @@
+<?php
+
+// Long-lived bg worker relying on the engine for its parking: it does not
+// call set_time_limit(0), so max_execution_time must not cut the run
+// short, and it parks in a blocking read without a stream timeout, so
+// default_socket_timeout must not end the read either. Counts its runs in
+// BG_COUNT_FILE, so anything that interrupts the park shows up as a second
+// line.
+file_put_contents($_SERVER['BG_COUNT_FILE'], "run\n", FILE_APPEND);
+frankenphp_worker_tick();
+fgets(frankenphp_get_worker_handle());
diff --git a/testdata/bgworker/pool.php b/testdata/bgworker/pool.php
new file mode 100644
index 0000000000..8446459393
--- /dev/null
+++ b/testdata/bgworker/pool.php
@@ -0,0 +1,12 @@
+<?php
+
+// Pool bg worker: num > 1 threads share the name; each touches a file of
+// its own under BG_SENTINEL_DIR, then parks on its own handle.
+set_time_limit(0);
+@touch($_SERVER['BG_SENTINEL_DIR'] . DIRECTORY_SEPARATOR . bin2hex(random_bytes(8)));
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/read.php b/testdata/bgworker/read.php
new file mode 100644
index 0000000000..3ef3a66f4c
--- /dev/null
+++ b/testdata/bgworker/read.php
@@ -0,0 +1,10 @@
+<?php
+
+// Long-lived bg worker parking with a blocking read instead of
+// stream_select(): the read returns on the EOF of a drain too.
+set_time_limit(0);
+if (!empty($_SERVER['BG_SENTINEL'])) {
+    @touch($_SERVER['BG_SENTINEL']);
+}
+frankenphp_worker_tick();
+fgets(frankenphp_get_worker_handle());
diff --git a/testdata/bgworker/readable.php b/testdata/bgworker/readable.php
new file mode 100644
index 0000000000..47f1b13d41
--- /dev/null
+++ b/testdata/bgworker/readable.php
@@ -0,0 +1,25 @@
+<?php
+
+// Reports whether the handle is still readable after a tick: the tick
+// consumes the wake-ups, including the one sent at start, so a script that
+// ticked has nothing left to read until the next one or the drain.
+$handle = frankenphp_get_worker_handle();
+$poll = static function () use ($handle): string {
+    $read = [$handle];
+    $write = $except = null;
+
+    return stream_select($read, $write, $except, 0) > 0 ? 'readable' : 'quiet';
+};
+
+$seen = ['start:' . $poll()];
+frankenphp_worker_tick();
+$seen[] = 'after tick:' . $poll();
+frankenphp_worker_tick();
+$seen[] = 'after second tick:' . $poll();
+file_put_contents($_SERVER['BG_SENTINEL'], implode(' ', $seen));
+
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/recv.php b/testdata/bgworker/recv.php
new file mode 100644
index 0000000000..10ffd47262
--- /dev/null
+++ b/testdata/bgworker/recv.php
@@ -0,0 +1,11 @@
+<?php
+
+// Long-lived bg worker parking in stream_socket_recvfrom(), a blocking
+// receive that reaches the stream through its transport rather than the
+// read op: it returns on the EOF of a drain too.
+set_time_limit(0);
+if (!empty($_SERVER['BG_SENTINEL'])) {
+    @touch($_SERVER['BG_SENTINEL']);
+}
+frankenphp_worker_tick();
+stream_socket_recvfrom(frankenphp_get_worker_handle(), 1);
diff --git a/testdata/bgworker/refetch.php b/testdata/bgworker/refetch.php
new file mode 100644
index 0000000000..6ca7014aa7
--- /dev/null
+++ b/testdata/bgworker/refetch.php
@@ -0,0 +1,17 @@
+<?php
+
+// Bg worker checking the handle cache: two fetches of a run are the same
+// stream, a fetch after closing it is a fresh one, and the drain still
+// reaches the script through that one. Writes what it saw to BG_SENTINEL,
+// then parks.
+$first = frankenphp_get_worker_handle();
+$second = frankenphp_get_worker_handle();
+$result = $first === $second ? 'same' : 'different';
+
+fclose($first);
+$third = frankenphp_get_worker_handle();
+$result .= $third === $second ? ' then same' : ' then fresh';
+
+file_put_contents($_SERVER['BG_SENTINEL'], $result);
+frankenphp_worker_tick();
+fgets($third);
diff --git a/testdata/bgworker/slow-boot.php b/testdata/bgworker/slow-boot.php
new file mode 100644
index 0000000000..fb0f60c208
--- /dev/null
+++ b/testdata/bgworker/slow-boot.php
@@ -0,0 +1,11 @@
+<?php
+
+// Boots slower than max_execution_time allows and never reaches its first
+// frankenphp_worker_tick(): the limit ends the run, a boot failure. Counts
+// its boots in BG_COUNT_FILE. A busy loop rather than a sleep, the limit is
+// checked between opcodes.
+file_put_contents($_SERVER['BG_COUNT_FILE'], "boot\n", FILE_APPEND);
+$until = microtime(true) + 5;
+while (microtime(true) < $until) {
+}
+frankenphp_worker_tick();
diff --git a/testdata/bgworker/stuck.php b/testdata/bgworker/stuck.php
new file mode 100644
index 0000000000..51c15e3f6b
--- /dev/null
+++ b/testdata/bgworker/stuck.php
@@ -0,0 +1,18 @@
+<?php
+
+// Reaches the ready point, then ignores its handle and sleeps on the first
+// run: only the force-kill can end that run, which is what the reboot test
+// proves. Later runs park properly so the shutdown stays quick.
+set_time_limit(0);
+frankenphp_worker_tick();
+if (!file_exists($_SERVER['BG_ONCE'])) {
+    @touch($_SERVER['BG_ONCE']);
+    sleep(60);
+}
+@touch($_SERVER['BG_SENTINEL']);
+$handle = frankenphp_get_worker_handle();
+while (frankenphp_worker_tick()) {
+    $read = [$handle];
+    $write = $except = null;
+    stream_select($read, $write, $except, null);
+}
diff --git a/testdata/bgworker/tick.php b/testdata/bgworker/tick.php
new file mode 100644
index 0000000000..5614f16458
--- /dev/null
+++ b/testdata/bgworker/tick.php
@@ -0,0 +1,17 @@
+<?php
+
+// Records what frankenphp_worker_tick() returns: true twice while running,
+// then false twice once drained, the second one proving the drain sticks.
+$handle = frankenphp_get_worker_handle();
+$seen = [];
+$seen[] = frankenphp_worker_tick() ? 'true' : 'false';
+$seen[] = frankenphp_worker_tick() ? 'true' : 'false';
+file_put_contents($_SERVER['BG_SENTINEL'], implode(' ', $seen));
+
+$read = [$handle];
+$write = $except = null;
+stream_select($read, $write, $except, null);
+
+$seen[] = frankenphp_worker_tick() ? 'true' : 'false';
+$seen[] = frankenphp_worker_tick() ? 'true' : 'false';
+file_put_contents($_SERVER['BG_SENTINEL'], implode(' ', $seen));
diff --git a/testdata/handle-outside.php b/testdata/handle-outside.php
new file mode 100644
index 0000000000..c338d9b8cf
--- /dev/null
+++ b/testdata/handle-outside.php
@@ -0,0 +1,10 @@
+<?php
+
+foreach (['frankenphp_get_worker_handle', 'frankenphp_worker_tick'] as $function) {
+    try {
+        $function();
+        echo "$function: no exception\n";
+    } catch (\RuntimeException $e) {
+        echo $e->getMessage(), "\n";
+    }
+}
diff --git a/testdata/symlinks/test/index.php b/testdata/symlinks/test/index.php
index 15aa1a9cf1..9037dbe762 100644
--- a/testdata/symlinks/test/index.php
+++ b/testdata/symlinks/test/index.php
@@ -1,7 +1,7 @@
 <?php
 
 if (!isset($_SERVER['FRANKENPHP_WORKER'])) {
-    die("Error: This script must be run in worker mode (FRANKENPHP_WORKER not set to '1')\n");
+    die("Error: This script must be run in worker mode (FRANKENPHP_WORKER not set)\n");
 }
 
 $i = 0;
diff --git a/testdata/symlinks/test/nested/index.php b/testdata/symlinks/test/nested/index.php
index 3d07bc8d89..98622ba57f 100644
--- a/testdata/symlinks/test/nested/index.php
+++ b/testdata/symlinks/test/nested/index.php
@@ -1,7 +1,7 @@
 <?php
 
 if (!isset($_SERVER['FRANKENPHP_WORKER'])) {
-    die("Error: This script must be run in worker mode (FRANKENPHP_WORKER not set to '1')\n");
+    die("Error: This script must be run in worker mode (FRANKENPHP_WORKER not set)\n");
 }
 
 $i = 0;
diff --git a/testdata/worker-name.php b/testdata/worker-name.php
new file mode 100644
index 0000000000..b9f15a047d
--- /dev/null
+++ b/testdata/worker-name.php
@@ -0,0 +1,11 @@
+<?php
+
+// HTTP worker echoing what identified it at boot: FRANKENPHP_WORKER as it
+// always was, and whether the background variable was set.
+$name = $_SERVER['FRANKENPHP_WORKER'] ?? 'unset';
+$mode = isset($_SERVER['FRANKENPHP_WORKER_BACKGROUND']) ? 'background' : 'http';
+$handler = static function () use ($name, $mode) {
+    echo "$name $mode";
+};
+while (frankenphp_handle_request($handler)) {
+}
diff --git a/threadbackgroundworker.go b/threadbackgroundworker.go
new file mode 100644
index 0000000000..4d260b569d
--- /dev/null
+++ b/threadbackgroundworker.go
@@ -0,0 +1,287 @@
+package frankenphp
+
+// /* closesocket() lives in ws2_32: the PHP dll links it, a cgo build does not by itself */
+// #cgo windows LDFLAGS: -lws2_32
+// #include "frankenphp.h"
+import "C"
+import (
+	"fmt"
+	"log/slog"
+	"sync/atomic"
+	"time"
+
+	"github.com/dunglas/frankenphp/internal/state"
+)
+
+// backgroundWorkerThread is the threadHandler of background worker scripts.
+// It owns their lifecycle: boot the script, re-run it when it exits, restart
+// it with a quadratic backoff when it crashes. Background workers share the
+// PHP runtime with HTTP threads but never receive HTTP requests. The script
+// can park on the stream returned by frankenphp_get_worker_handle(), which
+// reaches EOF when the thread is drained, and frankenphp_worker_tick() then
+// returns false, so it exits gracefully on shutdown, reboot or handler
+// transition.
+type backgroundWorkerThread struct {
+	workerLifecycle
+
+	// context of the current run, a background worker serves no request
+	context      *frankenPHPContext
+	failureCount int // number of consecutive failed runs
+
+	// crashCount is the number of runs that crashed past their ready point
+	// in a row, paces their restarts; a cooperative exit resets it. Only
+	// touched on the PHP thread.
+	crashCount int
+
+	// isBootingScript is true until the current run calls
+	// frankenphp_worker_tick(), the background analog of an HTTP worker
+	// reaching frankenphp_handle_request(). Only touched on the PHP thread
+	// (setup, the C callback during execution, teardown).
+	isBootingScript bool
+
+	// bootTimer warns when a run has not called frankenphp_worker_tick()
+	// after backgroundBootWarnDelay; only touched on the PHP thread
+	bootTimer *time.Timer
+
+	// stopSock holds the Go side's end of this thread's stop socket pair
+	// (per thread so pool workers drain independently); the other end is
+	// exposed to the script via frankenphp_get_worker_handle(). Wide enough
+	// for a Windows SOCKET, -1 when not held. Atomic because drain() closes
+	// it from another goroutine.
+	stopSock atomic.Int64
+}
+
+// backgroundBootWarnDelay is how long a run may go without calling
+// frankenphp_worker_tick() before a warning: Init() and Shutdown() wait for
+// that point, so a script that never gets there hangs both silently
+const backgroundBootWarnDelay = 10 * time.Second
+
+func convertToBackgroundWorkerThread(thread *phpThread, worker *worker) {
+	handler := &backgroundWorkerThread{workerLifecycle: newWorkerLifecycle(thread, worker)}
+	handler.stopSock.Store(-1)
+	thread.setHandler(handler)
+	worker.attachThread(thread)
+}
+
+func (handler *backgroundWorkerThread) name() string {
+	return "Background Worker PHP Thread - " + handler.worker.fileName
+}
+
+func (handler *backgroundWorkerThread) frankenPHPContext() *frankenPHPContext {
+	return handler.context
+}
+
+// drain closes the Go side's end of the stop socket pair so a script
+// parked on the other end wakes up with EOF and can exit its loop. Called
+// right before drainChan is closed on shutdown and reboot; also reused
+// internally to release the socket on the other exit paths.
+func (handler *backgroundWorkerThread) drain() {
+	if s := handler.stopSock.Swap(-1); s >= 0 {
+		C.frankenphp_worker_close_stop_sock(C.intptr_t(s))
+	}
+}
+
+func (handler *backgroundWorkerThread) beforeScriptExecution() string {
+	return handler.workerLifecycle.beforeScriptExecution(handler.startScript)
+}
+
+// startScript keeps trying to start the script: unlike an HTTP worker, whose
+// setup cannot fail, a background worker needs a socket pair per run
+func (handler *backgroundWorkerThread) startScript() string {
+	for {
+		err := handler.setupScript()
+		if err == nil {
+			return handler.worker.fileName
+		}
+
+		if globalLogger.Enabled(globalCtx, slog.LevelError) {
+			globalLogger.LogAttrs(globalCtx, slog.LevelError, "failed to start background worker", slog.String("worker", handler.worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.Any("error", err))
+		}
+
+		// fail fast during startup so Init() surfaces the error to the
+		// operator; past startup, back off and retry like a crash
+		if reportStartupFailure(err) {
+			handler.thread.state.Set(state.ShuttingDown)
+
+			return handler.beforeScriptExecution()
+		}
+
+		handler.backoff()
+		if !handler.state.Is(state.Ready) && !handler.state.Is(state.TransitionComplete) {
+			// drained during the backoff (shutdown, reboot, transition)
+			return handler.beforeScriptExecution()
+		}
+	}
+}
+
+// setupScript marks the thread as a background worker on the C side and
+// takes ownership of the Go side's end of its stop socket pair.
+func (handler *backgroundWorkerThread) setupScript() error {
+	s := int64(C.frankenphp_set_background_worker_and_get_stop_sock())
+	if s < 0 {
+		return fmt.Errorf("failed to create the stop socket pair of background worker %q", handler.worker.qualifiedName)
+	}
+	handler.stopSock.Store(s)
+
+	switch handler.state.Get() {
+	case state.ShuttingDown, state.Rebooting, state.ForceRebooting, state.TransitionRequested:
+		// a concurrent drain may have run before the socket was published;
+		// close it now so the script observes EOF immediately
+		handler.drain()
+	}
+
+	fc, err := newWorkerDummyContext(handler.worker)
+	if err != nil {
+		handler.drain()
+		return err
+	}
+	handler.context = fc
+
+	handler.isBootingScript = true
+	metrics.StartWorker(handler.worker.qualifiedName)
+	// the run's logger and context, not the globals: Stop() does not wait
+	// for a callback that already started, and a shutdown finishing
+	// meanwhile resets those
+	logger, ctx, name, threadIndex := fc.logger, fc.ctx, handler.worker.qualifiedName, handler.thread.threadIndex
+	handler.bootTimer = time.AfterFunc(backgroundBootWarnDelay, func() {
+		if logger.Enabled(ctx, slog.LevelWarn) {
+			logger.LogAttrs(ctx, slog.LevelWarn, "background worker has not called frankenphp_worker_tick() yet, Init() and Shutdown() wait for it", slog.String("worker", name), slog.Int("thread", threadIndex))
+		}
+	})
+
+	if fc.logger.Enabled(fc.ctx, slog.LevelDebug) {
+		fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "starting background worker", slog.String("worker", handler.worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
+	}
+
+	// the thread stays in TransitionComplete until the script calls
+	// frankenphp_worker_tick(), see go_frankenphp_background_worker_ready
+
+	return nil
+}
+
+func (handler *backgroundWorkerThread) afterScriptExecution(exitStatus int) {
+	// the Go side's end of the stop socket pair belongs to this thread;
+	// release it on every exit path so the next run gets a fresh pair
+	// (drain() already took it when the exit was drain-triggered)
+	handler.drain()
+	worker := handler.worker
+	handler.context = nil
+
+	handler.stopBootTimer()
+	handler.state.MarkAsWaiting(false)
+
+	// cooperative exit: the script ticked and returned cleanly, re-run it,
+	// unless the thread is being drained (beforeScriptExecution checks the
+	// state)
+	if exitStatus == 0 && !handler.isBootingScript {
+		handler.crashCount = 0
+		metrics.StopWorker(worker.qualifiedName, StopReasonRestart)
+
+		if globalLogger.Enabled(globalCtx, slog.LevelDebug) {
+			globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "restarting background worker", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
+		}
+
+		return
+	}
+
+	// crash after the ready point: restart without counting toward
+	// max_consecutive_failures, that cap is about a script that never boots.
+	// The wait still applies: unlike an HTTP worker, which can only crash
+	// after a request reached frankenphp_handle_request() and is therefore
+	// paced by traffic, a background worker reaches its ready point on its
+	// own and a script crashing right after it would spin
+	if !handler.isBootingScript {
+		metrics.StopWorker(worker.qualifiedName, StopReasonCrash)
+
+		if globalLogger.Enabled(globalCtx, slog.LevelWarn) {
+			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "background worker crashed, restarting", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.Int("exit_status", exitStatus), slog.Int("crashes", handler.crashCount))
+		}
+
+		time.Sleep(restartBackoff(handler.crashCount))
+		handler.crashCount++
+
+		return
+	}
+
+	// boot failure: the script exited before calling frankenphp_worker_tick(),
+	// a clean exit included, which would otherwise respawn in a tight loop.
+	// StopReasonBootFailure skips the ready-gauge decrement, matching the
+	// ReadyWorker call that never happened
+	metrics.StopWorker(worker.qualifiedName, StopReasonBootFailure)
+
+	// max_consecutive_failures only fails hard during startup, where it
+	// surfaces on startupFailChan so Init() returns the error to the
+	// operator. Past startup, a failing background worker keeps
+	// restarting with a louder log line: silently giving up would leave
+	// the server in a broken half-state with no clear way to recover.
+	pastCap := worker.maxConsecutiveFailures >= 0 && handler.failureCount >= worker.maxConsecutiveFailures
+	if pastCap && !watcherIsEnabled {
+		var err error
+		if exitStatus == 0 {
+			err = fmt.Errorf("background worker %s exits without calling frankenphp_worker_tick()", worker.fileName)
+		} else {
+			err = fmt.Errorf("too many consecutive failures: background worker %s keeps crashing", worker.fileName)
+		}
+		if reportStartupFailure(err) {
+			handler.thread.state.Set(state.ShuttingDown)
+			return
+		}
+	}
+
+	logLevel := slog.LevelWarn
+	logMsg := "background worker failed before calling frankenphp_worker_tick(), restarting"
+	if exitStatus == 0 {
+		logMsg = "background worker exited without calling frankenphp_worker_tick(), restarting"
+	}
+	if pastCap {
+		logLevel = slog.LevelError
+		logMsg = "background worker exceeded max_consecutive_failures, still restarting"
+	}
+	if globalLogger.Enabled(globalCtx, logLevel) {
+		globalLogger.LogAttrs(globalCtx, logLevel, logMsg, slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.Int("failures", handler.failureCount), slog.Int("exit_status", exitStatus))
+	}
+
+	handler.backoff()
+}
+
+func (handler *backgroundWorkerThread) stopBootTimer() {
+	if handler.bootTimer != nil {
+		handler.bootTimer.Stop()
+		handler.bootTimer = nil
+	}
+}
+
+//export go_frankenphp_background_worker_ready
+func go_frankenphp_background_worker_ready(threadIndex C.uintptr_t) {
+	// called on the PHP thread by the first frankenphp_worker_tick() of a
+	// run; the handler is a backgroundWorkerThread because that function
+	// throws on every other thread kind, and a thread reaching this without
+	// one would wait out Init() instead
+	handler, ok := phpThreads[threadIndex].handler.(*backgroundWorkerThread)
+	if !ok {
+		panic("frankenphp_worker_tick() called on a thread that is not a background worker")
+	}
+
+	if handler.isBootingScript {
+		handler.isBootingScript = false
+		// the boot succeeded, only consecutive boot failures count
+		handler.failureCount = 0
+		handler.stopBootTimer()
+		metrics.ReadyWorker(handler.worker.qualifiedName)
+		// parked from now on as far as the threads state endpoint is concerned
+		handler.state.MarkAsWaiting(true)
+
+		// like an HTTP worker reaching frankenphp_handle_request(), the thread
+		// is ready only now: initWorkers() waits for this state, so a script
+		// that fails before its first tick still fails Init()
+		if handler.state.Is(state.TransitionComplete) {
+			handler.state.Set(state.Ready)
+		}
+	}
+}
+
+// backoff waits before the next run of a crashed script, see restartBackoff
+func (handler *backgroundWorkerThread) backoff() {
+	time.Sleep(restartBackoff(handler.failureCount))
+	handler.failureCount++
+}
diff --git a/threadworker.go b/threadworker.go
index 8a308b4d87..c37e1fb674 100644
--- a/threadworker.go
+++ b/threadworker.go
@@ -15,9 +15,8 @@ import (
 // executes the PHP worker script in a loop
 // implements the threadHandler interface
 type workerThread struct {
-	state                   *state.ThreadState
-	thread                  *phpThread
-	worker                  *worker
+	workerLifecycle
+
 	dummyFrankenPHPContext  *frankenPHPContext
 	workerFrankenPHPContext *frankenPHPContext
 	isBootingScript         bool // true if the worker has not reached frankenphp_handle_request yet
@@ -26,49 +25,19 @@ type workerThread struct {
 }
 
 func convertToWorkerThread(thread *phpThread, worker *worker) {
-	thread.setHandler(&workerThread{
-		state:  thread.state,
-		thread: thread,
-		worker: worker,
-	})
+	thread.setHandler(&workerThread{workerLifecycle: newWorkerLifecycle(thread, worker)})
 	worker.attachThread(thread)
 }
 
-// beforeScriptExecution returns the name of the script or an empty string on shutdown
 func (handler *workerThread) beforeScriptExecution() string {
-	switch handler.state.Get() {
-	case state.TransitionRequested:
-		if handler.worker.onThreadShutdown != nil {
-			handler.worker.onThreadShutdown(handler.thread.threadIndex)
-		}
-		handler.worker.detachThread(handler.thread)
-		return handler.thread.transitionToNewHandler()
-	case state.Ready, state.TransitionComplete:
-		handler.thread.updateContext(true)
-		if handler.worker.onThreadReady != nil {
-			handler.worker.onThreadReady(handler.thread.threadIndex)
-		}
-
-		setupWorkerScript(handler, handler.worker)
+	return handler.workerLifecycle.beforeScriptExecution(handler.startScript)
+}
 
-		return handler.worker.fileName
-	case state.Rebooting, state.ForceRebooting:
-		return ""
-	case state.RebootReady:
-		handler.requestCount = 0
-		handler.state.Set(state.Ready)
-		return handler.beforeScriptExecution()
-	case state.ShuttingDown:
-		if handler.worker.onThreadShutdown != nil {
-			handler.worker.onThreadShutdown(handler.thread.threadIndex)
-		}
-		handler.worker.detachThread(handler.thread)
+// startScript runs the worker script; it always has one to run
+func (handler *workerThread) startScript() string {
+	setupWorkerScript(handler, handler.worker)
 
-		// signal to stop
-		return ""
-	default:
-		panic("unexpected state: " + handler.state.Name())
-	}
+	return handler.worker.fileName
 }
 
 func (handler *workerThread) afterScriptExecution(exitStatus int) {
@@ -90,7 +59,7 @@ func (handler *workerThread) name() string {
 func (handler *workerThread) drain() {}
 
 func setupWorkerScript(handler *workerThread, worker *worker) {
-	metrics.StartWorker(worker.name)
+	metrics.StartWorker(worker.qualifiedName)
 
 	// Create a dummy request to set up the worker
 	fc, err := newWorkerDummyContext(worker)
@@ -103,7 +72,7 @@ func setupWorkerScript(handler *workerThread, worker *worker) {
 	handler.requestCount = 0
 
 	if fc.logger.Enabled(fc.ctx, slog.LevelDebug) {
-		fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "starting", slog.String("worker", worker.name), slog.Int("thread", handler.thread.threadIndex))
+		fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "starting", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
 	}
 }
 
@@ -122,10 +91,10 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 
 	// on exit status 0 we just run the worker script again
 	if exitStatus == 0 && !handler.isBootingScript {
-		metrics.StopWorker(worker.name, StopReasonRestart)
+		metrics.StopWorker(worker.qualifiedName, StopReasonRestart)
 
 		if globalLogger.Enabled(globalCtx, slog.LevelDebug) {
-			globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "restarting", slog.String("worker", worker.name), slog.Int("thread", handler.thread.threadIndex), slog.Int("exit_status", exitStatus))
+			globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "restarting", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.Int("exit_status", exitStatus))
 		}
 
 		return
@@ -133,9 +102,9 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 
 	// worker has thrown a fatal error or has not reached frankenphp_handle_request
 	if handler.isBootingScript {
-		metrics.StopWorker(worker.name, StopReasonBootFailure)
+		metrics.StopWorker(worker.qualifiedName, StopReasonBootFailure)
 	} else {
-		metrics.StopWorker(worker.name, StopReasonCrash)
+		metrics.StopWorker(worker.qualifiedName, StopReasonCrash)
 	}
 
 	if !handler.isBootingScript {
@@ -143,14 +112,14 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 		// unlike a clean restart, this took down any in-flight request, so
 		// surface it above debug level, with the exit status needed to triage it
 		if globalLogger.Enabled(globalCtx, slog.LevelWarn) {
-			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "unexpected termination, restarting", slog.String("worker", worker.name), slog.Int("thread", handler.thread.threadIndex), slog.Int("exit_status", exitStatus))
+			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "unexpected termination, restarting", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.Int("exit_status", exitStatus))
 		}
 
 		return
 	}
 
-	if worker.maxConsecutiveFailures >= 0 && startupFailChan != nil && !watcherIsEnabled && handler.failureCount >= worker.maxConsecutiveFailures {
-		startupFailChan <- fmt.Errorf("too many consecutive failures: worker %s has not reached frankenphp_handle_request()", worker.fileName)
+	if worker.maxConsecutiveFailures >= 0 && !watcherIsEnabled && handler.failureCount >= worker.maxConsecutiveFailures &&
+		reportStartupFailure(fmt.Errorf("too many consecutive failures: worker %s has not reached frankenphp_handle_request()", worker.fileName)) {
 		handler.thread.state.Set(state.ShuttingDown)
 		return
 	}
@@ -158,23 +127,32 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 	if watcherIsEnabled {
 		// worker script has probably failed due to script changes while watcher is enabled
 		if globalLogger.Enabled(globalCtx, slog.LevelError) {
-			globalLogger.LogAttrs(globalCtx, slog.LevelError, "(watcher enabled) worker script has not reached frankenphp_handle_request()", slog.String("worker", worker.name), slog.Int("thread", handler.thread.threadIndex))
+			globalLogger.LogAttrs(globalCtx, slog.LevelError, "(watcher enabled) worker script has not reached frankenphp_handle_request()", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
 		}
 	} else {
 		// rare case where worker script has failed on a restart during normal operation
 		// this can happen if startup success depends on external resources
 		if globalLogger.Enabled(globalCtx, slog.LevelWarn) {
-			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "worker script has failed on restart", slog.String("worker", worker.name), slog.Int("thread", handler.thread.threadIndex), slog.Int("failures", handler.failureCount))
+			globalLogger.LogAttrs(globalCtx, slog.LevelWarn, "worker script has failed on restart", slog.String("worker", worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.Int("failures", handler.failureCount))
 		}
 	}
 
-	// wait a bit and try again (exponential backoff)
-	backoffDuration := time.Duration(handler.failureCount*handler.failureCount*100) * time.Millisecond
-	if backoffDuration > time.Second {
-		backoffDuration = time.Second
-	}
+	// wait a bit and try again
+	time.Sleep(restartBackoff(handler.failureCount))
 	handler.failureCount++
-	time.Sleep(backoffDuration)
+}
+
+// restartBackoff is the wait before a worker script is re-run after a
+// failure: quadratic in the number of consecutive failures, capped at one
+// second; shared by HTTP and background workers. The cap comes before the
+// multiplication, which overflows a duration past some 300k failures, a
+// count a crash loop reaches on its own in a few days
+func restartBackoff(failures int) time.Duration {
+	if failures >= 4 {
+		return time.Second
+	}
+
+	return time.Duration(failures*failures*100) * time.Millisecond
 }
 
 // waitForWorkerRequest is called during frankenphp_handle_request in the php worker script.
@@ -183,7 +161,7 @@ func (handler *workerThread) waitForWorkerRequest() (bool, any) {
 	handler.thread.Unpin()
 
 	if globalLogger.Enabled(globalCtx, slog.LevelDebug) {
-		globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "waiting for request", slog.String("worker", handler.worker.name), slog.Int("thread", handler.thread.threadIndex))
+		globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "waiting for request", slog.String("worker", handler.worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
 	}
 
 	// Clear the first dummy request created to initialize the worker
@@ -195,14 +173,14 @@ func (handler *workerThread) waitForWorkerRequest() (bool, any) {
 		}
 
 		// worker is truly ready only after reaching frankenphp_handle_request()
-		metrics.ReadyWorker(handler.worker.name)
+		metrics.ReadyWorker(handler.worker.qualifiedName)
 	}
 
 	// max_requests reached: signal reboot for full ZTS cleanup
 	if maxRequestsPerThread > 0 && handler.requestCount >= maxRequestsPerThread {
 		if globalLogger.Enabled(globalCtx, slog.LevelDebug) {
 			globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "max requests reached, restarting",
-				slog.String("worker", handler.worker.name),
+				slog.String("worker", handler.worker.qualifiedName),
 				slog.Int("thread", handler.thread.threadIndex),
 				slog.Int("max_requests", maxRequestsPerThread),
 			)
@@ -223,7 +201,7 @@ func (handler *workerThread) waitForWorkerRequest() (bool, any) {
 	select {
 	case <-handler.thread.drainChan:
 		if globalLogger.Enabled(globalCtx, slog.LevelDebug) {
-			globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "shutting down", slog.String("worker", handler.worker.name), slog.Int("thread", handler.thread.threadIndex))
+			globalLogger.LogAttrs(globalCtx, slog.LevelDebug, "shutting down", slog.String("worker", handler.worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
 		}
 
 		return false, nil
@@ -239,9 +217,9 @@ func (handler *workerThread) waitForWorkerRequest() (bool, any) {
 
 	if fc.logger.Enabled(fc.ctx, slog.LevelDebug) {
 		if handler.workerFrankenPHPContext.request == nil {
-			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling started", slog.String("worker", handler.worker.name), slog.Int("thread", handler.thread.threadIndex))
+			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling started", slog.String("worker", handler.worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex))
 		} else {
-			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling started", slog.String("worker", handler.worker.name), slog.Int("thread", handler.thread.threadIndex), slog.String("url", handler.workerFrankenPHPContext.request.RequestURI))
+			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling started", slog.String("worker", handler.worker.qualifiedName), slog.Int("thread", handler.thread.threadIndex), slog.String("url", handler.workerFrankenPHPContext.request.RequestURI))
 		}
 	}
 
@@ -298,9 +276,9 @@ func go_frankenphp_finish_worker_request(threadIndex C.uintptr_t, retval *C.zval
 
 	if fc.logger.Enabled(fc.ctx, slog.LevelDebug) {
 		if fc.request == nil {
-			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling finished", slog.String("worker", fc.worker.name), slog.Int("thread", thread.threadIndex))
+			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling finished", slog.String("worker", fc.worker.qualifiedName), slog.Int("thread", thread.threadIndex))
 		} else {
-			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling finished", slog.String("worker", fc.worker.name), slog.Int("thread", thread.threadIndex), slog.String("url", fc.request.RequestURI))
+			fc.logger.LogAttrs(fc.ctx, slog.LevelDebug, "request handling finished", slog.String("worker", fc.worker.qualifiedName), slog.Int("thread", thread.threadIndex), slog.String("url", fc.request.RequestURI))
 		}
 	}
 }
diff --git a/threadworker_test.go b/threadworker_test.go
new file mode 100644
index 0000000000..24e5a2e410
--- /dev/null
+++ b/threadworker_test.go
@@ -0,0 +1,20 @@
+package frankenphp
+
+import (
+	"math"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRestartBackoff(t *testing.T) {
+	assert.Equal(t, time.Duration(0), restartBackoff(0))
+	assert.Equal(t, 100*time.Millisecond, restartBackoff(1))
+	assert.Equal(t, 400*time.Millisecond, restartBackoff(2))
+	assert.Equal(t, 900*time.Millisecond, restartBackoff(3))
+	assert.Equal(t, time.Second, restartBackoff(4))
+	// a crash loop counts without bound, the quadratic must not overflow
+	assert.Equal(t, time.Second, restartBackoff(303701))
+	assert.Equal(t, time.Second, restartBackoff(math.MaxInt32))
+}
diff --git a/types_test.go b/types_test.go
index a08f90725e..7d547e9681 100644
--- a/types_test.go
+++ b/types_test.go
@@ -14,7 +14,7 @@ func testOnDummyPHPThread(t *testing.T, test func()) {
 	t.Helper()
 
 	globalLogger = slog.Default()
-	_, err := initPHPThreads(1, 1, nil) // boot 1 thread
+	_, err := initPHPThreads(1, 1, 0, nil) // boot 1 thread
 	assert.NoError(t, err)
 	handler := convertToTaskThread(phpThreads[0])
 
diff --git a/worker.go b/worker.go
index 388dfbd031..44e4a020f1 100644
--- a/worker.go
+++ b/worker.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -20,7 +21,11 @@ import (
 type worker struct {
 	mercureContext
 
-	name                   string
+	// name as declared, unique within its server (or among global workers)
+	name string
+	// qualifiedName is unique across the process: "<server name>:<name>" for
+	// server-scoped workers, name otherwise; used for metrics and logs
+	qualifiedName          string
 	fileName               string
 	matchRequest           func(*http.Request) bool
 	num                    int
@@ -34,14 +39,18 @@ type worker struct {
 	onThreadShutdown       func(int)
 	queuedRequests         atomic.Int32
 	server                 *Server
+	// isBackgroundWorker marks this as a background (non-HTTP) worker
+	isBackgroundWorker bool
 }
 
 var (
-	workers             []*worker
-	workersByName       map[string]*worker
-	globalWorkersByPath map[string]*worker
-	watcherIsEnabled    bool
-	startupFailChan     chan error
+	workers          []*worker
+	watcherIsEnabled bool
+	startupFailChan  chan error
+	// startupPhase is true while initWorkers() waits for the workers to
+	// boot, the only time a boot failure must reach startupFailChan: past
+	// that point the handlers log and keep restarting on their own
+	startupPhase atomic.Bool
 )
 
 func initWorkers(opts []workerOpt) error {
@@ -55,8 +64,7 @@ func initWorkers(opts []workerOpt) error {
 	)
 
 	workers = make([]*worker, 0, len(opts))
-	workersByName = make(map[string]*worker, len(opts))
-	globalWorkersByPath = make(map[string]*worker, len(opts))
+	qualifiedNames := make(map[string]bool, len(opts))
 
 	for _, o := range opts {
 		w, err := newWorker(o)
@@ -64,22 +72,40 @@ func initWorkers(opts []workerOpt) error {
 			return err
 		}
 
-		totalThreadsToStart += w.num
-		workers = append(workers, w)
-		workersByName[w.name] = w
-		if w.server == nil {
-			globalWorkersByPath[w.fileName] = w
-		} else if err := w.server.addWorker(w); err != nil {
+		if w.server != fallbackServer && !slices.Contains(servers, w.server) {
+			return fmt.Errorf("worker %q is scoped to a server that was not passed to WithServer()", w.name)
+		}
+
+		// names and paths are unique within a server
+		if err := w.server.addWorker(w); err != nil {
 			return err
 		}
+
+		// scoping makes qualified names unique in all but pathological
+		// cases: a global worker may still be named like the "<server>:<name>"
+		// of a scoped one, and metrics would merge the two series
+		if qualifiedNames[w.qualifiedName] {
+			return fmt.Errorf("two workers cannot report under the same name: %q", w.qualifiedName)
+		}
+		qualifiedNames[w.qualifiedName] = true
+
+		totalThreadsToStart += w.num
+		workers = append(workers, w)
+		// reported here rather than in calculateMaxThreads(), where the name is not resolved yet
+		metrics.TotalWorkers(w.qualifiedName, w.num)
 	}
 
 	startupFailChan = make(chan error, totalThreadsToStart)
+	startupPhase.Store(true)
 
 	for _, w := range workers {
 		for range w.num {
 			thread := getInactivePHPThread()
-			convertToWorkerThread(thread, w)
+			if w.isBackgroundWorker {
+				convertToBackgroundWorkerThread(thread, w)
+			} else {
+				convertToWorkerThread(thread, w)
+			}
 
 			workersReady.Go(func() {
 				thread.state.WaitFor(state.Ready, state.ShuttingDown, state.Done)
@@ -88,6 +114,7 @@ func initWorkers(opts []workerOpt) error {
 	}
 
 	workersReady.Wait()
+	startupPhase.Store(false)
 
 	select {
 	case err := <-startupFailChan:
@@ -95,12 +122,29 @@ func initWorkers(opts []workerOpt) error {
 		return fmt.Errorf("failed to initialize workers: %w", err)
 	default:
 		// all workers started successfully
-		startupFailChan = nil
 	}
 
 	return nil
 }
 
+// reportStartupFailure hands a boot failure to initWorkers() while it waits
+// for the workers, so Init() fails, and reports whether it did: past that
+// point the failure is dropped, the handler has logged it and keeps
+// restarting. It never blocks, the buffer holds one error per thread and a
+// thread failing repeatedly in the startup window must not hang on it
+func reportStartupFailure(err error) bool {
+	if !startupPhase.Load() {
+		return false
+	}
+
+	select {
+	case startupFailChan <- err:
+	default:
+	}
+
+	return true
+}
+
 func newWorker(o workerOpt) (*worker, error) {
 	// Order is important!
 	// This order ensures that FrankenPHP started from inside a symlinked directory will properly resolve any paths.
@@ -119,23 +163,38 @@ func newWorker(o workerOpt) (*worker, error) {
 		return nil, fmt.Errorf("worker file not found %q: %w", absFileName, err)
 	}
 
+	if o.isBackgroundWorker {
+		// the name is the script's identity (exposed via FRANKENPHP_WORKER);
+		// empty names are reserved for the catch-all workers of a future build
+		if o.name == "" {
+			return nil, fmt.Errorf("background worker %q must have an explicit name", o.fileName)
+		}
+		if o.matchRequest != nil {
+			return nil, fmt.Errorf("background worker %q cannot match requests", o.name)
+		}
+		if o.maxThreads > 0 {
+			return nil, fmt.Errorf("background worker %q cannot set max_threads, it does not autoscale", o.name)
+		}
+		// Workers.SendRequest() and SendMessage() dispatch on requestChan,
+		// which no background thread reads
+		if o.extensionWorkers != nil {
+			return nil, fmt.Errorf("background worker %q cannot be an extension worker, those handle requests", o.name)
+		}
+	}
+
 	if o.name == "" {
 		o.name = absFileName
 	}
 
-	if o.server == nil {
-		if globalWorkersByPath[absFileName] != nil {
-			return nil, fmt.Errorf("two global workers cannot have the same filename: %q", absFileName)
-		}
-
-		// no server means no set of requests to match against, the matcher would never run
-		if o.matchRequest != nil {
-			return nil, fmt.Errorf("worker %q has a request matcher but no server scope, use WithWorkerServerScope()", o.name)
-		}
+	// no server means no set of requests to match against, the matcher would never run
+	if o.server == nil && o.matchRequest != nil {
+		return nil, fmt.Errorf("worker %q has a request matcher but no server scope, use WithWorkerServerScope()", o.name)
 	}
 
-	if workersByName[o.name] != nil {
-		return nil, fmt.Errorf("two workers cannot have the same name: %q", o.name)
+	// the same name may be declared in several servers, metrics and logs need a unique one
+	qualifiedName := o.name
+	if o.server != nil {
+		qualifiedName = o.server.name + ":" + o.name
 	}
 
 	// env should always contain FRANKENPHP_WORKER and the parent php_server env
@@ -152,10 +211,19 @@ func newWorker(o workerOpt) (*worker, error) {
 		}
 	}
 
-	o.env["FRANKENPHP_WORKER\x00"] = "1"
+	// $_SERVER['FRANKENPHP_WORKER'] identifies an HTTP worker, as it always
+	// did, and $_SERVER['FRANKENPHP_WORKER_BACKGROUND'] a background one,
+	// holding its declared name: a script serving both roles tests which of
+	// the two is set
+	if o.isBackgroundWorker {
+		o.env["FRANKENPHP_WORKER_BACKGROUND\x00"] = o.name
+	} else {
+		o.env["FRANKENPHP_WORKER\x00"] = "1"
+	}
 
 	w := &worker{
 		name:                   o.name,
+		qualifiedName:          qualifiedName,
 		fileName:               absFileName,
 		matchRequest:           o.matchRequest,
 		requestOptions:         o.requestOptions,
@@ -167,6 +235,14 @@ func newWorker(o workerOpt) (*worker, error) {
 		onThreadReady:          o.onThreadReady,
 		onThreadShutdown:       o.onThreadShutdown,
 		server:                 o.server,
+		isBackgroundWorker:     o.isBackgroundWorker,
+	}
+
+	// a worker declared without a scope belongs to the fallback server, the
+	// one serving the requests that have no server either, so a worker
+	// always has one
+	if w.server == nil {
+		w.server = fallbackServer
 	}
 
 	w.configureMercure(&o)
@@ -235,7 +311,7 @@ func (worker *worker) isAtThreadLimit() bool {
 }
 
 func (worker *worker) handleRequest(fc *frankenPHPContext) error {
-	metrics.StartWorkerRequest(worker.name)
+	metrics.StartWorkerRequest(worker.qualifiedName)
 
 	runtime.Gosched()
 
@@ -247,7 +323,7 @@ func (worker *worker) handleRequest(fc *frankenPHPContext) error {
 			case thread.requestChan <- fc:
 				worker.threadMutex.RUnlock()
 				<-fc.done
-				metrics.StopWorkerRequest(worker.name, time.Since(fc.startedAt))
+				metrics.StopWorkerRequest(worker.qualifiedName, time.Since(fc.startedAt))
 
 				return nil
 			default:
@@ -259,7 +335,7 @@ func (worker *worker) handleRequest(fc *frankenPHPContext) error {
 
 	// if no thread was available, mark the request as queued and apply the scaling strategy
 	worker.queuedRequests.Add(1)
-	metrics.QueuedWorkerRequest(worker.name)
+	metrics.QueuedWorkerRequest(worker.qualifiedName)
 
 	for {
 		workerScaleChan := scaleChan
@@ -270,9 +346,9 @@ func (worker *worker) handleRequest(fc *frankenPHPContext) error {
 		select {
 		case worker.requestChan <- fc:
 			worker.queuedRequests.Add(-1)
-			metrics.DequeuedWorkerRequest(worker.name)
+			metrics.DequeuedWorkerRequest(worker.qualifiedName)
 			<-fc.done
-			metrics.StopWorkerRequest(worker.name, time.Since(fc.startedAt))
+			metrics.StopWorkerRequest(worker.qualifiedName, time.Since(fc.startedAt))
 
 			return nil
 		case workerScaleChan <- fc:
@@ -280,8 +356,8 @@ func (worker *worker) handleRequest(fc *frankenPHPContext) error {
 		case <-timeoutChan(time.Duration(maxWaitTime.Load())):
 			// the request has timed out stalling
 			worker.queuedRequests.Add(-1)
-			metrics.DequeuedWorkerRequest(worker.name)
-			metrics.StopWorkerRequest(worker.name, time.Since(fc.startedAt))
+			metrics.DequeuedWorkerRequest(worker.qualifiedName)
+			metrics.StopWorkerRequest(worker.qualifiedName, time.Since(fc.startedAt))
 
 			fc.reject(ErrMaxWaitTimeExceeded)
 
diff --git a/workerextension.go b/workerextension.go
index 814eea1565..01dab1d58b 100644
--- a/workerextension.go
+++ b/workerextension.go
@@ -26,25 +26,30 @@ type extensionWorkers struct {
 
 // EXPERIMENTAL: SendRequest sends an HTTP request to the worker and writes the response to the provided ResponseWriter.
 func (w *extensionWorkers) SendRequest(rw http.ResponseWriter, r *http.Request) error {
-	fr, err := NewRequestWithContext(
-		r,
-		WithOriginalRequest(r),
-		WithWorkerName(w.name),
-	)
-
-	if err != nil {
-		return err
+	// the worker only exists between Init() and Shutdown()
+	if w.internalWorker == nil {
+		return ErrNotRunning
 	}
 
-	return ServeHTTP(rw, fr)
+	// worker names are resolved within a server, and a worker always has
+	// one, the fallback server when it was declared without a scope
+	return w.internalWorker.server.ServeHTTP(rw, r, WithOriginalRequest(r), WithWorkerName(w.name))
 }
 
 func (w *extensionWorkers) NumThreads() int {
+	if w.internalWorker == nil {
+		return 0
+	}
+
 	return w.internalWorker.countThreads()
 }
 
 // EXPERIMENTAL: SendMessage sends a message to the worker and waits for a response.
 func (w *extensionWorkers) SendMessage(ctx context.Context, message any, rw http.ResponseWriter) (any, error) {
+	if w.internalWorker == nil {
+		return nil, ErrNotRunning
+	}
+
 	fc := newContextFromMessage(message, rw, ctx, w.internalWorker)
 	err := w.internalWorker.handleRequest(fc)
 
diff --git a/workerextension_test.go b/workerextension_test.go
index e861ec97a3..f8dfab0a23 100644
--- a/workerextension_test.go
+++ b/workerextension_test.go
@@ -77,6 +77,36 @@ func TestWorkerExtensionSendMessage(t *testing.T) {
 	assert.Equal(t, "received message: Hello Workers", ret)
 }
 
+// an extension worker scoped to a server stays reachable through
+// SendRequest(), which resolves the name within that server
+func TestWorkerExtensionOnServer(t *testing.T) {
+	t.Cleanup(Shutdown)
+
+	server, err := NewServer("testdata/", WithServerName("api"))
+	require.NoError(t, err)
+	externalWorker, o := WithExtensionWorkers("scopedWorker", "testdata/worker.php", 1, WithWorkerServerScope(server))
+	require.NoError(t, Init(o, WithServer(server)))
+
+	// a URI that does not match the worker's own script, so only the name
+	// lookup can route this to it
+	w := httptest.NewRecorder()
+	require.NoError(t, externalWorker.SendRequest(w, httptest.NewRequest("GET", "http://example.com/index.php", nil)))
+
+	body, err := io.ReadAll(w.Result().Body)
+	require.NoError(t, err)
+	assert.Contains(t, string(body), "Requests handled: 0")
+}
+
+// background workers never read requestChan, so an extension cannot send
+// them requests or messages
+func TestErrorIfExtensionWorkerIsBackground(t *testing.T) {
+	t.Cleanup(Shutdown)
+
+	_, o := WithExtensionWorkers("backgroundExtension", "testdata/bgworker/basic.php", 1, WithWorkerBackground())
+
+	require.ErrorContains(t, Init(o), "cannot be an extension worker")
+}
+
 func TestErrorIf2WorkersHaveSameName(t *testing.T) {
 	_, o1 := WithExtensionWorkers("duplicateWorker", "testdata/worker.php", 1)
 	_, o2 := WithExtensionWorkers("duplicateWorker", "testdata/worker2.php", 1)
diff --git a/workerlifecycle.go b/workerlifecycle.go
new file mode 100644
index 0000000000..4d1809ee22
--- /dev/null
+++ b/workerlifecycle.go
@@ -0,0 +1,58 @@
+package frankenphp
+
+import "github.com/dunglas/frankenphp/internal/state"
+
+// workerLifecycle is the part of a worker thread that HTTP and background
+// workers share: the thread, its worker, and the states both walk through
+// between two runs of the script. Handlers embed it and pass the one step
+// that differs, how a run starts.
+type workerLifecycle struct {
+	state  *state.ThreadState
+	thread *phpThread
+	worker *worker
+}
+
+func newWorkerLifecycle(thread *phpThread, worker *worker) workerLifecycle {
+	return workerLifecycle{state: thread.state, thread: thread, worker: worker}
+}
+
+// beforeScriptExecution returns the name of the script to run, or an empty
+// string to stop the thread; startScript prepares a run and returns the
+// script to execute, or an empty string to stop the thread
+func (l *workerLifecycle) beforeScriptExecution(startScript func() string) string {
+	switch l.state.Get() {
+	case state.TransitionRequested:
+		l.detach()
+
+		return l.thread.transitionToNewHandler()
+	case state.Ready, state.TransitionComplete:
+		l.thread.updateContext(true)
+		if l.worker.onThreadReady != nil {
+			l.worker.onThreadReady(l.thread.threadIndex)
+		}
+
+		return startScript()
+	case state.Rebooting, state.ForceRebooting:
+		return ""
+	case state.RebootReady:
+		l.state.Set(state.Ready)
+
+		return l.beforeScriptExecution(startScript)
+	case state.ShuttingDown:
+		l.detach()
+
+		// signal to stop
+		return ""
+	default:
+		panic("unexpected state: " + l.state.Name())
+	}
+}
+
+// detach takes the thread off its worker, on the paths that stop running its
+// script for good
+func (l *workerLifecycle) detach() {
+	if l.worker.onThreadShutdown != nil {
+		l.worker.onThreadShutdown(l.thread.threadIndex)
+	}
+	l.worker.detachThread(l.thread)
+}