fix(logger): honor LOG_LEVEL

DEVELOPMENT.md

@@ -300,7 +300,7 @@ The application respects these environment variables:
 - `PROMETHEUS_URL` - Prometheus server URL
 - `GRAFANA_URL` - Grafana server URL  
 - `GRAFANA_API_KEY` - Grafana API authentication key
-- `LOG_LEVEL` - Logging level (debug, info, warn, error)
+- `LOG_LEVEL` - Logging level (debug, info, warn, error); unset or invalid values fall back to info
 
 ### Configuration Files
 

internal/logger/logger.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"log/slog"
 	"os"
+	"strings"
 
 	"go.opentelemetry.io/otel/trace"
 )
@@ -12,19 +13,37 @@ import (
 // stderr, keeping stdout free for the MCP stdio protocol.
 const UseStderrEnv = "KAGENT_USE_STDERR"
 
+// LogLevelEnv names the environment variable that sets the minimum log level
+// (debug, info, warn or error). Unset or invalid values fall back to info.
+const LogLevelEnv = "LOG_LEVEL"
+
 var globalLogger *slog.Logger
 
 // UseStderr reports whether console output must go to stderr.
 func UseStderr() bool {
 	return os.Getenv(UseStderrEnv) == "true"
 }
 
+// levelFromEnv returns the level named by LOG_LEVEL, or info when it is unset
+// or not a valid slog level.
+func levelFromEnv() slog.Level {
+	value := strings.TrimSpace(os.Getenv(LogLevelEnv))
+	if value == "" {
+		return slog.LevelInfo
+	}
+	var level slog.Level
+	if err := level.UnmarshalText([]byte(value)); err != nil {
+		return slog.LevelInfo
+	}
+	return level
+}
+
 // Init initializes the global logger
 // If useStderr is true, logs will be written to stderr (for stdio mode)
 // If useStderr is false, logs will be written to stdout (for HTTP mode)
 func Init(useStderr bool) {
 	opts := &slog.HandlerOptions{
-		Level: slog.LevelInfo,
+		Level: levelFromEnv(),
 	}
 
 	// Choose output destination based on mode

internal/logger/logger_test.go

@@ -132,3 +132,30 @@ func TestUseStderr(t *testing.T) {
 	t.Setenv(UseStderrEnv, "false")
 	require.False(t, UseStderr())
 }
+
+func TestInitHonorsLogLevel(t *testing.T) {
+	cases := []struct {
+		value     string
+		wantDebug bool
+		wantInfo  bool
+		wantWarn  bool
+	}{
+		{value: "", wantDebug: false, wantInfo: true, wantWarn: true},
+		{value: "debug", wantDebug: true, wantInfo: true, wantWarn: true},
+		{value: "DEBUG", wantDebug: true, wantInfo: true, wantWarn: true},
+		{value: "info", wantDebug: false, wantInfo: true, wantWarn: true},
+		{value: "warn", wantDebug: false, wantInfo: false, wantWarn: true},
+		{value: "error", wantDebug: false, wantInfo: false, wantWarn: false},
+		{value: "verbose", wantDebug: false, wantInfo: true, wantWarn: true},
+	}
+	for _, tc := range cases {
+		t.Run("LOG_LEVEL="+tc.value, func(t *testing.T) {
+			t.Setenv("LOG_LEVEL", tc.value)
+			Init(true)
+			ctx := context.Background()
+			assert.Equal(t, tc.wantDebug, Get().Enabled(ctx, slog.LevelDebug), "debug")
+			assert.Equal(t, tc.wantInfo, Get().Enabled(ctx, slog.LevelInfo), "info")
+			assert.Equal(t, tc.wantWarn, Get().Enabled(ctx, slog.LevelWarn), "warn")
+		})
+	}
+}