diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c8235cd..ac031aa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -113,7 +113,7 @@ jobs:
         run: |
           set -euo pipefail
           dex_log="$RUNNER_TEMP/dexcli.log"
-          PATH="$PWD/.cache/temporal-v1.8.2:$PATH" .cache/dexcli-v0.11.2 dev \
+          PATH="$PWD/.cache/temporal-v1.8.2:$PATH" .cache/dexcli-v0.12.1 dev \
             -open=false \
             -blob-store-dir "$RUNNER_TEMP/dex-blobs" \
             -sqlite-db-filename "$RUNNER_TEMP/dex.sqlite.db" \
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 1378953..1c5b6d3 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -12,7 +12,7 @@ against the installed released SDK and a version-matched runnable example or
 real-server compile-contract test.
 
 Snapshot, Stream, Channel size snapshot, and Attribute wait code target Dex Go
-SDK `v0.11.2`. Workers negotiate the Server protocol before binding. Recheck
+SDK `v0.12.1`. Workers negotiate the Server protocol before binding. Recheck
 the installed SDK source and the installed skill before changing resource
 projection or errors. Never infer an API from a design screenshot or unreleased
 branch.
diff --git a/Makefile b/Makefile
index 748a701..f057388 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@
 
 GO_BUILD_CACHE := $(CURDIR)/.cache/go-build
 GO_PACKAGES := ./agent/... ./cmd/... ./internal/... ./model/... ./toolcontract/...
-DEXCLI_VERSION := v0.11.2
+DEXCLI_VERSION := v0.12.1
 DEXCLI_BINARY := $(CURDIR)/.cache/dexcli-$(DEXCLI_VERSION)
 OSV_SCANNER_VERSION := v2.5.1
 OSV_SCANNER_BINARY := $(CURDIR)/.cache/osv-scanner-$(OSV_SCANNER_VERSION)
@@ -72,7 +72,7 @@ check-flow-definition: install-dexcli
 		trap 'rm -r "$${flow_definition_tmp}"' EXIT; \
 		cd "$(CURDIR)"; \
 		flow_definition="$${flow_definition_tmp}/ai-agent.json"; \
-		if ! GOCACHE=$(GO_BUILD_CACHE) "$(DEXCLI_BINARY)" visualize internal/agent/flow.go --language go --json \
+		if ! GOCACHE=$(GO_BUILD_CACHE) GOWORK=off "$(DEXCLI_BINARY)" visualize internal/agent/flow.go --language go --json \
 			--out "$${flow_definition_tmp}/ai-agent"; then \
 			test ! -f "$${flow_definition}" || sed -n '/"diagnostics"/,$$p' "$${flow_definition}"; \
 			exit 1; \
diff --git a/README.md b/README.md
index 3a45c39..d27223c 100644
--- a/README.md
+++ b/README.md
@@ -118,7 +118,7 @@ and resource model.
 
 - Go matching [`go.mod`](go.mod)
 - Node.js and npm compatible with [`web/package-lock.json`](web/package-lock.json)
-- A Dex Server `v0.11.2`
+- A Dex Server `v0.12.1`
 - A writable directory for disposable Dex BlobCache data
 
 ## Quick start
@@ -131,7 +131,7 @@ make build-api
 make build-web
 ```
 
-Start a compatible Dex server. Dex Go SDK `v0.11.2` Workers require the Server
+Start a compatible Dex server. Dex Go SDK `v0.12.1` Workers require the Server
 compatibility RPC, so upgrade the Server before the Worker. Then run the API and
 Worker:
 
diff --git a/docs/flow-model.md b/docs/flow-model.md
index 7b93a83..2762ffa 100644
--- a/docs/flow-model.md
+++ b/docs/flow-model.md
@@ -14,7 +14,7 @@
   `GetArchivedMessages`
 - Browser synchronization Attribute: `WaitingInputRound`
 
-The implementation requires Dex Go SDK `v0.11.2` and Server `v0.11.2`. Each
+The implementation requires Dex Go SDK `v0.12.1` and Server `v0.12.1`. Each
 `WaitFor`, `Execute`, and RPC invocation is an independent Dex atomic commit.
 Provider and MCP calls are external effects and are not part of a Dex
 transaction.
@@ -215,7 +215,7 @@ the Flow's ASYNC default. A long-running definition explicitly selects SYNC.
 ASYNC fallback changes where the attempt runs; it does not change that resolved
 durability.
 
-Dex Server `v0.11.2` and Go SDK `v0.11.2` expose Channel size metadata in `WaitFor` and
+Dex Server `v0.12.1` and Go SDK `v0.12.1` expose Channel size metadata in `WaitFor` and
 `Execute`. `AwaitUser.WaitFor` reads the
 sizes of `SteeredUserMessages`, `QueuedUserMessages`, and the current
 `PlanExecutions` instance without loading message payloads. It increments
diff --git a/go.mod b/go.mod
index 7b1d4f5..50c6db8 100644
--- a/go.mod
+++ b/go.mod
@@ -12,7 +12,7 @@ require (
 	github.com/ogen-go/ogen v1.24.0
 	github.com/openai/openai-go/v3 v3.55.0
 	github.com/superdurable/dex/blob-cache-go v0.1.0
-	github.com/superdurable/dex/sdk-go v0.11.2
+	github.com/superdurable/dex/sdk-go v0.12.1
 	golang.org/x/net v0.58.0
 	gopkg.in/yaml.v3 v3.0.1
 )
diff --git a/go.sum b/go.sum
index 42189d3..356c793 100644
--- a/go.sum
+++ b/go.sum
@@ -62,8 +62,8 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/superdurable/dex/blob-cache-go v0.1.0 h1:+c3H5YBWG3DlICOHbgT9IUM5vTlfLYGP5Vd5sWr7WTY=
 github.com/superdurable/dex/blob-cache-go v0.1.0/go.mod h1:Atepb7+sztvDCztVKmlvEKCSKFCkHKtDhoFYjaFmtEw=
-github.com/superdurable/dex/sdk-go v0.11.2 h1:XiODrJ9JlTOKYM9jfUn5EIm8ZI7Be7i4+3tjmQ7cy3w=
-github.com/superdurable/dex/sdk-go v0.11.2/go.mod h1:8Wj5wPf9dyb7hDnA40j8xISR/zjhX57NrUDVcXgf5x8=
+github.com/superdurable/dex/sdk-go v0.12.1 h1:x5cBR4XRMdy/Hi16BDusMZ3MfHAt0+/LfRR7NNLFzmw=
+github.com/superdurable/dex/sdk-go v0.12.1/go.mod h1:8Wj5wPf9dyb7hDnA40j8xISR/zjhX57NrUDVcXgf5x8=
 github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/gjson v1.19.0 h1:xwxm7n691Uf3u5OFjzngavjGTh55KX5q/9w9xHW88JU=
 github.com/tidwall/gjson v1.19.0/go.mod h1:V37/opeE/JbLUOfH0QTXiNez2l0RUjYUhpT4szFQAfc=
diff --git a/internal/agent/flow.go b/internal/agent/flow.go
index 0d15899..73fdf1f 100644
--- a/internal/agent/flow.go
+++ b/internal/agent/flow.go
@@ -112,11 +112,9 @@ func NewFlow(modelClient ModelClient, tools ToolRegistry, options ...FlowOption)
 	return flow
 }
 
-const flowTypeAIAgent = "AIAgentFlow"
-
 // GetFlowType pins the durable Flow identity.
 func (*Flow) GetFlowType() string {
-	return flowTypeAIAgent
+	return "AIAgentFlow"
 }
 
 // GetSteps registers the state-machine nodes.
@@ -1911,35 +1909,11 @@ const (
 	continueExecuteTool       continuation = "execute_tool"
 	continueDurableWait       continuation = "durable_wait"
 
-	stepTypeInit                  stepType = "Init"
-	stepTypeAwaitUser             stepType = "AwaitUser"
-	stepTypeAnsweredInput         stepType = "AnsweredInput"
-	stepTypeCompactContext        stepType = "CompactContext"
-	stepTypeCallModel             stepType = "CallModel"
-	stepTypeBeforeModelCall       stepType = "BeforeModelCall"
-	stepTypeCallModelWithHooks    stepType = "CallModelWithHooks"
-	stepTypeAfterModelCall        stepType = "AfterModelCall"
-	stepTypeApplyModelResult      stepType = "ApplyModelResult"
-	stepTypeCheckSteered          stepType = "CheckSteered"
-	stepTypeRouteTool             stepType = "RouteTool"
-	stepTypeAwaitApproval         stepType = "AwaitToolApproval"
-	stepTypeExecuteTool           stepType = "ExecuteTool"
-	stepTypeRecoverTool           stepType = "RecoverToolExecution"
-	stepTypeExecuteParallel       stepType = "ExecuteParallelTool"
-	stepTypeRecoverParallel       stepType = "RecoverParallelToolExecution"
-	stepTypeAwaitParallel         stepType = "AwaitParallelToolResults"
-	stepTypePrepareManualRecovery stepType = "PrepareManualToolRecovery"
-	stepTypeAwaitManualRecovery   stepType = "AwaitManualToolRecovery"
-	stepTypeDurableWait           stepType = "DurableWait"
-	stepTypeInactivityTimeout     stepType = "InactivityTimeout"
-
 	maximumSteeringMessageCount       = 2_147_483_647
 	maximumAutomaticPlanRecoveryCount = 1
 )
 
 type continuation string
-type stepType string
-
 type modelCallKind string
 
 const (
@@ -2149,7 +2123,7 @@ type initStep struct {
 
 var _ dex.Step[AgentConfig] = initStep{}
 
-func (initStep) GetStepType() string { return string(stepTypeInit) }
+func (initStep) GetStepType() string { return "Init" }
 
 func (initStep) GetStepOptions() *dex.StepOptions { return defaultStepOptions }
 
@@ -2188,7 +2162,7 @@ type awaitUserStep struct {
 
 var _ dex.Step[dex.None] = awaitUserStep{}
 
-func (awaitUserStep) GetStepType() string { return string(stepTypeAwaitUser) }
+func (awaitUserStep) GetStepType() string { return "AwaitUser" }
 
 func (awaitUserStep) GetStepOptions() *dex.StepOptions { return awaitUserStepOptions }
 
@@ -2360,7 +2334,7 @@ type answeredInputStep struct {
 
 var _ dex.Step[dex.None] = answeredInputStep{}
 
-func (answeredInputStep) GetStepType() string { return string(stepTypeAnsweredInput) }
+func (answeredInputStep) GetStepType() string { return "AnsweredInput" }
 
 func (answeredInputStep) GetStepOptions() *dex.StepOptions { return messageContextStepOptions }
 
@@ -2391,7 +2365,7 @@ type compactContextStep struct {
 
 var _ dex.Step[Sequence] = compactContextStep{}
 
-func (compactContextStep) GetStepType() string { return string(stepTypeCompactContext) }
+func (compactContextStep) GetStepType() string { return "CompactContext" }
 
 func (compactContextStep) GetStepOptions() *dex.StepOptions { return modelStepOptions }
 
@@ -2468,7 +2442,7 @@ type callModelStep struct {
 
 var _ dex.Step[dex.None] = callModelStep{}
 
-func (callModelStep) GetStepType() string { return string(stepTypeCallModel) }
+func (callModelStep) GetStepType() string { return "CallModel" }
 
 func (callModelStep) GetStepOptions() *dex.StepOptions { return modelStepOptions }
 
@@ -2619,7 +2593,7 @@ type beforeModelCallStep struct {
 
 var _ dex.Step[modelCallPreparation] = beforeModelCallStep{}
 
-func (beforeModelCallStep) GetStepType() string { return string(stepTypeBeforeModelCall) }
+func (beforeModelCallStep) GetStepType() string { return "BeforeModelCall" }
 
 func (beforeModelCallStep) GetStepOptions() *dex.StepOptions { return modelStepOptions }
 
@@ -2675,7 +2649,7 @@ type callModelWithHooksStep struct {
 
 var _ dex.Step[modelCallInput] = callModelWithHooksStep{}
 
-func (callModelWithHooksStep) GetStepType() string { return string(stepTypeCallModelWithHooks) }
+func (callModelWithHooksStep) GetStepType() string { return "CallModelWithHooks" }
 
 func (callModelWithHooksStep) GetStepOptions() *dex.StepOptions { return modelStepOptions }
 
@@ -2706,7 +2680,7 @@ type afterModelCallStep struct {
 
 var _ dex.Step[modelCallResult] = afterModelCallStep{}
 
-func (afterModelCallStep) GetStepType() string { return string(stepTypeAfterModelCall) }
+func (afterModelCallStep) GetStepType() string { return "AfterModelCall" }
 
 func (afterModelCallStep) GetStepOptions() *dex.StepOptions { return modelStepOptions }
 
@@ -2739,7 +2713,7 @@ type applyModelResultStep struct {
 
 var _ dex.Step[modelCallResult] = applyModelResultStep{}
 
-func (applyModelResultStep) GetStepType() string { return string(stepTypeApplyModelResult) }
+func (applyModelResultStep) GetStepType() string { return "ApplyModelResult" }
 
 func (applyModelResultStep) GetStepOptions() *dex.StepOptions { return modelStepOptions }
 
@@ -3050,7 +3024,7 @@ type checkSteeredStep struct {
 
 var _ dex.Step[continuation] = checkSteeredStep{}
 
-func (checkSteeredStep) GetStepType() string { return string(stepTypeCheckSteered) }
+func (checkSteeredStep) GetStepType() string { return "CheckSteered" }
 
 func (checkSteeredStep) GetStepOptions() *dex.StepOptions { return messageContextStepOptions }
 
@@ -3123,7 +3097,7 @@ type routeToolStep struct {
 
 var _ dex.Step[dex.None] = routeToolStep{}
 
-func (routeToolStep) GetStepType() string { return string(stepTypeRouteTool) }
+func (routeToolStep) GetStepType() string { return "RouteTool" }
 
 func (routeToolStep) GetStepOptions() *dex.StepOptions { return messageMutationStepOptions }
 
@@ -3362,7 +3336,7 @@ type awaitToolApprovalStep struct {
 
 var _ dex.Step[dex.None] = awaitToolApprovalStep{}
 
-func (awaitToolApprovalStep) GetStepType() string { return string(stepTypeAwaitApproval) }
+func (awaitToolApprovalStep) GetStepType() string { return "AwaitToolApproval" }
 
 func (awaitToolApprovalStep) GetStepOptions() *dex.StepOptions { return messageMutationStepOptions }
 
@@ -3566,7 +3540,7 @@ type executeToolStep struct {
 
 var _ dex.Step[dex.None] = executeToolStep{}
 
-func (executeToolStep) GetStepType() string { return string(stepTypeExecuteTool) }
+func (executeToolStep) GetStepType() string { return "ExecuteTool" }
 
 func (step executeToolStep) Execute(ctx dex.Context, _ dex.None) (*dex.StepDecision, error) {
 	if err := step.flow.updateStatus(ctx, AgentStatusExecutingTool); err != nil {
@@ -3639,7 +3613,7 @@ type recoverToolExecutionStep struct {
 
 var _ dex.Step[dex.None] = recoverToolExecutionStep{}
 
-func (recoverToolExecutionStep) GetStepType() string { return string(stepTypeRecoverTool) }
+func (recoverToolExecutionStep) GetStepType() string { return "RecoverToolExecution" }
 
 func (recoverToolExecutionStep) GetStepOptions() *dex.StepOptions {
 	return messageMutationStepOptions
@@ -3678,7 +3652,7 @@ type executeParallelToolStep struct {
 
 var _ dex.Step[parallelToolExecutionInput] = executeParallelToolStep{}
 
-func (executeParallelToolStep) GetStepType() string { return string(stepTypeExecuteParallel) }
+func (executeParallelToolStep) GetStepType() string { return "ExecuteParallelTool" }
 
 func (step executeParallelToolStep) Execute(
 	ctx dex.Context,
@@ -3750,7 +3724,7 @@ type recoverParallelToolExecutionStep struct {
 var _ dex.Step[parallelToolExecutionInput] = recoverParallelToolExecutionStep{}
 
 func (recoverParallelToolExecutionStep) GetStepType() string {
-	return string(stepTypeRecoverParallel)
+	return "RecoverParallelToolExecution"
 }
 
 func (recoverParallelToolExecutionStep) GetStepOptions() *dex.StepOptions {
@@ -3788,7 +3762,7 @@ type awaitParallelToolResultsStep struct {
 
 var _ dex.Step[awaitParallelToolResultsInput] = awaitParallelToolResultsStep{}
 
-func (awaitParallelToolResultsStep) GetStepType() string { return string(stepTypeAwaitParallel) }
+func (awaitParallelToolResultsStep) GetStepType() string { return "AwaitParallelToolResults" }
 
 func (awaitParallelToolResultsStep) GetStepOptions() *dex.StepOptions {
 	return messageMutationStepOptions
@@ -3858,7 +3832,7 @@ type prepareManualToolRecoveryStep struct {
 var _ dex.Step[dex.None] = prepareManualToolRecoveryStep{}
 
 func (prepareManualToolRecoveryStep) GetStepType() string {
-	return string(stepTypePrepareManualRecovery)
+	return "PrepareManualToolRecovery"
 }
 
 func (prepareManualToolRecoveryStep) GetStepOptions() *dex.StepOptions {
@@ -3910,7 +3884,7 @@ type awaitManualToolRecoveryStep struct {
 var _ dex.Step[toolBatchState] = awaitManualToolRecoveryStep{}
 
 func (awaitManualToolRecoveryStep) GetStepType() string {
-	return string(stepTypeAwaitManualRecovery)
+	return "AwaitManualToolRecovery"
 }
 
 func (awaitManualToolRecoveryStep) GetStepOptions() *dex.StepOptions {
@@ -4177,7 +4151,7 @@ type durableWaitStep struct {
 
 var _ dex.Step[dex.None] = durableWaitStep{}
 
-func (durableWaitStep) GetStepType() string { return string(stepTypeDurableWait) }
+func (durableWaitStep) GetStepType() string { return "DurableWait" }
 
 func (durableWaitStep) GetStepOptions() *dex.StepOptions { return durableWaitStepOptions }
 
@@ -4288,7 +4262,7 @@ type inactivityTimeoutStep struct {
 var _ dex.Step[time.Time] = inactivityTimeoutStep{}
 
 func (inactivityTimeoutStep) GetStepType() string {
-	return string(stepTypeInactivityTimeout)
+	return "InactivityTimeout"
 }
 
 func (inactivityTimeoutStep) GetStepOptions() *dex.StepOptions {
diff --git a/internal/agent/flow_integration_test.go b/internal/agent/flow_integration_test.go
index ee25b83..225306a 100644
--- a/internal/agent/flow_integration_test.go
+++ b/internal/agent/flow_integration_test.go
@@ -3531,17 +3531,17 @@ func waitForStepCompletionForTestOnly(
 	t *testing.T,
 	environment *agentIntegrationEnvironment,
 	flowID FlowID,
-	step stepType,
+	stepType string,
 	execution int32,
 ) {
 	t.Helper()
 	ctx, cancel := context.WithTimeout(t.Context(), integrationWaitTimeout)
 	defer cancel()
 	if err := environment.sdk.WaitForStepCompletion(ctx, string(flowID), dex.StepExecutionID{
-		StepType:        string(step),
+		StepType:        stepType,
 		ExecutionNumber: &execution,
 	}, dex.WaitForStepCompletionOptions{}); err != nil {
-		t.Fatalf("wait for %s completion: %v", step, err)
+		t.Fatalf("wait for %s completion: %v", stepType, err)
 	}
 }
 
diff --git a/script/install-dexcli.sh b/script/install-dexcli.sh
index 5abc7c4..54a5deb 100755
--- a/script/install-dexcli.sh
+++ b/script/install-dexcli.sh
@@ -22,10 +22,10 @@ esac
 
 archive_name="dexcli_${version}_${operating_system}_${architecture}.tar.gz"
 case "$archive_name" in
-  dexcli_v0.11.2_darwin_amd64.tar.gz) checksum=e4ed297423044e5789ad1693bb5242e776ca9dd92b858fefd77ad92b317f84bd ;;
-  dexcli_v0.11.2_darwin_arm64.tar.gz) checksum=6b22eae6069133b23e2ae0cd22a5d7302305ef3fbfc613c2c52953080f42e859 ;;
-  dexcli_v0.11.2_linux_amd64.tar.gz) checksum=b14b0717bee605599b3f216e0af5bf75af406987547b895896c36c081a4744e5 ;;
-  dexcli_v0.11.2_linux_arm64.tar.gz) checksum=a062c5a75a9e21b7ff33609a58d5e475199b42298e866fefee619c36f0982aef ;;
+  dexcli_v0.12.1_darwin_amd64.tar.gz) checksum=6c07a261cb187cd334acaf481b50845bf29635aac6fe7c396f42192c4821759d ;;
+  dexcli_v0.12.1_darwin_arm64.tar.gz) checksum=158d5af3b89b0b6d5cba859e63440f81b57d18ca0396dfc3f03663abef63ec4b ;;
+  dexcli_v0.12.1_linux_amd64.tar.gz) checksum=b0c7f93de0a8b15a0a81243de089b8a3428a8633ae98d412667423e26712df42 ;;
+  dexcli_v0.12.1_linux_arm64.tar.gz) checksum=63285e3f23448e46b1cc9427fa72d6f1a1b7f05abada8bd63295dd23548d754d ;;
   *) echo "no checksum is pinned for $archive_name" >&2; exit 1 ;;
 esac