diff --git a/app/Http/Controllers/Api/WorkerController.php b/app/Http/Controllers/Api/WorkerController.php
index f9c7111c4..a36348918 100644
--- a/app/Http/Controllers/Api/WorkerController.php
+++ b/app/Http/Controllers/Api/WorkerController.php
@@ -1374,6 +1374,19 @@ public function pollWorkflowTasks(Request $request): JsonResponse
 
         $task = $this->formatTaskHistoryPagination($poll['task'] ?? null);
 
+        // PHP SDKs before 2.2.0 reject the valid StartAccepted prefix when
+        // a sticky hint triggers their authoritative-history fallback.
+        // They still receive the complete, paginated history and retain the
+        // previous full-replay behavior. Routing and lease identity are intact.
+        if ($task !== null
+            && $worker->runtime === 'php'
+            && is_string($worker->sdk_version)
+            && preg_match('/^durable-workflow-php\/v?(\d+\.\d+\.\d+(?:-[0-9A-Za-z.-]+)?)$/', $worker->sdk_version, $sdkVersion) === 1
+            && version_compare($sdkVersion[1], '2.2.0', '<')
+        ) {
+            $task['sticky_replay_mode'] = null;
+        }
+
         return WorkerProtocol::json([
             'task' => $task,
             'poll_status' => is_string($poll['poll_status'] ?? null)
diff --git a/app/Support/WorkflowTaskPoller.php b/app/Support/WorkflowTaskPoller.php
index 427e00dd6..d11325694 100644
--- a/app/Support/WorkflowTaskPoller.php
+++ b/app/Support/WorkflowTaskPoller.php
@@ -2061,6 +2061,9 @@ private function taskPayload(
                 )
                 : null,
             'run_status' => $history['run_status'] ?? null,
+            'sticky_worker_id' => $history['sticky_worker_id'] ?? $claim['sticky_worker_id'] ?? null,
+            'sticky_until' => $history['sticky_until'] ?? $claim['sticky_until'] ?? null,
+            'sticky_replay_mode' => $history['sticky_replay_mode'] ?? $claim['sticky_replay_mode'] ?? null,
             'last_history_sequence' => $history['last_history_sequence'],
             'total_history_events' => $history['total_history_events'],
             'history_size_bytes' => $history['history_size_bytes'],
diff --git a/composer.json b/composer.json
index 682d557b3..1a3cc5642 100644
--- a/composer.json
+++ b/composer.json
@@ -48,7 +48,7 @@
     },
     "extra": {
         "durable-workflow": {
-            "product-train": "2.5.9"
+            "product-train": "2.5.10"
         },
         "laravel": {
             "dont-discover": []
diff --git a/composer.lock b/composer.lock
index 22c0fb7e2..eabbb465f 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "8a4c0d6184514a21c024916b180913cc",
+    "content-hash": "bdfaa34c6710ee47c966a25241f8c167",
     "packages": [
         {
             "name": "apache/avro",
diff --git a/docker-compose.dedicated-matching.yml b/docker-compose.dedicated-matching.yml
index 518dd1910..056635e8a 100644
--- a/docker-compose.dedicated-matching.yml
+++ b/docker-compose.dedicated-matching.yml
@@ -32,13 +32,13 @@ name: durable-workflow-server
 # daemon reports `shape: dedicated`.
 
 # Generated by scripts/ci/sync-source-release.mjs. Do not edit the fallback.
-x-server-image: &server-image ${DW_SERVER_IMAGE:-durableworkflow/server:${DW_SERVER_TAG:-2.5.9}}
+x-server-image: &server-image ${DW_SERVER_IMAGE:-durableworkflow/server:${DW_SERVER_TAG:-2.5.10}}
 
 x-server-environment: &server-environment
   APP_NAME: "Durable Workflow Server"
   APP_ENV: ${APP_ENV:-local}
   DW_SERVER_KEY: ${DW_SERVER_KEY:-}
-  APP_VERSION: ${APP_VERSION:-${DW_SERVER_TAG:-2.5.9}}
+  APP_VERSION: ${APP_VERSION:-${DW_SERVER_TAG:-2.5.10}}
   APP_DEBUG: ${APP_DEBUG:-false}
   DB_CONNECTION: mysql
   DB_HOST: mysql
diff --git a/docker-compose.memo-rolling.yml b/docker-compose.memo-rolling.yml
index 002b639bc..a1bd5c0b4 100644
--- a/docker-compose.memo-rolling.yml
+++ b/docker-compose.memo-rolling.yml
@@ -49,14 +49,14 @@ services:
     command: ["server-bootstrap"]
     environment:
       <<: *runtime-environment
-      APP_VERSION: ${APP_VERSION:-2.5.9}
+      APP_VERSION: ${APP_VERSION:-2.5.10}
 
   successor:
     image: ${DW_MEMO_SUCCESSOR_IMAGE:-durable-workflow/server-memo-rolling:local}
     ports: !override []
     environment:
       <<: *runtime-environment
-      APP_VERSION: ${APP_VERSION:-2.5.9}
+      APP_VERSION: ${APP_VERSION:-2.5.10}
       DW_SERVER_ID: memo-successor
       DW_SERVER_TOPOLOGY_SHAPE: standalone_server
       DW_SERVER_PROCESS_CLASS: server_http_node
diff --git a/docker-compose.published.yml b/docker-compose.published.yml
index a3c0cd035..3032567b3 100644
--- a/docker-compose.published.yml
+++ b/docker-compose.published.yml
@@ -1,13 +1,13 @@
 name: durable-workflow-server
 
 # Generated by scripts/ci/sync-source-release.mjs. Do not edit the fallback.
-x-server-image: &server-image ${DW_SERVER_IMAGE:-durableworkflow/server:${DW_SERVER_TAG:-2.5.9}}
+x-server-image: &server-image ${DW_SERVER_IMAGE:-durableworkflow/server:${DW_SERVER_TAG:-2.5.10}}
 
 x-server-environment: &server-environment
   APP_NAME: "Durable Workflow Server"
   APP_ENV: ${APP_ENV:-local}
   DW_SERVER_KEY: ${DW_SERVER_KEY:-}
-  APP_VERSION: ${APP_VERSION:-${DW_SERVER_TAG:-2.5.9}}
+  APP_VERSION: ${APP_VERSION:-${DW_SERVER_TAG:-2.5.10}}
   APP_DEBUG: ${APP_DEBUG:-false}
   LOG_CHANNEL: ${LOG_CHANNEL:-stderr}
   LOG_LEVEL: ${LOG_LEVEL:-info}
diff --git a/docker-compose.small-cluster.yml b/docker-compose.small-cluster.yml
index 32711dd92..66b211265 100644
--- a/docker-compose.small-cluster.yml
+++ b/docker-compose.small-cluster.yml
@@ -12,7 +12,7 @@ x-server-build: &server-build
 x-server-environment: &server-environment
   APP_NAME: "Durable Workflow Server"
   APP_ENV: testing
-  APP_VERSION: ${APP_VERSION:-2.5.9}
+  APP_VERSION: ${APP_VERSION:-2.5.10}
   APP_DEBUG: "false"
   DW_SERVER_KEY: ${DW_SERVER_KEY:-base64:5Zt4nUhlCm3DD0nLXZJQdHiwPfb56yGo9gNV/g3jYbY=}
   DB_CONNECTION: ${DW_SMALL_CLUSTER_DB:-mysql}
diff --git a/docker-compose.yml b/docker-compose.yml
index 1d5f7dfe3..88a04697d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,7 +15,7 @@ services:
       DW_SERVER_KEY: "${DW_SERVER_KEY:-}"
       DW_SERVER_TOPOLOGY_SHAPE: standalone_server
       DW_SERVER_PROCESS_CLASS: server_http_node
-      APP_VERSION: "${APP_VERSION:-2.5.9}"
+      APP_VERSION: "${APP_VERSION:-2.5.10}"
       APP_DEBUG: "false"
       DB_CONNECTION: mysql
       DB_HOST: mysql
@@ -62,7 +62,7 @@ services:
       APP_NAME: "Durable Workflow Server"
       APP_ENV: local
       DW_SERVER_KEY: "${DW_SERVER_KEY:-}"
-      APP_VERSION: "${APP_VERSION:-2.5.9}"
+      APP_VERSION: "${APP_VERSION:-2.5.10}"
       APP_DEBUG: "false"
       DB_CONNECTION: mysql
       DB_HOST: mysql
@@ -124,7 +124,7 @@ services:
       DW_SERVER_KEY: "${DW_SERVER_KEY:-}"
       DW_SERVER_TOPOLOGY_SHAPE: standalone_server
       DW_SERVER_PROCESS_CLASS: worker_node
-      APP_VERSION: "${APP_VERSION:-2.5.9}"
+      APP_VERSION: "${APP_VERSION:-2.5.10}"
       DB_CONNECTION: mysql
       DB_HOST: mysql
       DB_PORT: 3306
@@ -178,7 +178,7 @@ services:
       DW_SERVER_KEY: "${DW_SERVER_KEY:-}"
       DW_SERVER_TOPOLOGY_SHAPE: standalone_server
       DW_SERVER_PROCESS_CLASS: scheduler_node
-      APP_VERSION: "${APP_VERSION:-2.5.9}"
+      APP_VERSION: "${APP_VERSION:-2.5.10}"
       DB_CONNECTION: mysql
       DB_HOST: mysql
       DB_PORT: 3306
diff --git a/k8s/README.md b/k8s/README.md
index 7f5443b84..a37cfa63d 100644
--- a/k8s/README.md
+++ b/k8s/README.md
@@ -13,7 +13,7 @@ The checked-in manifests are synchronized with the repository's stable source
 release and pin its Docker Hub tag:
 
 ```text
-durableworkflow/server:2.5.9
+durableworkflow/server:2.5.10
 ```
 
 Before production use, patch every workload image to the exact published tag or
@@ -21,15 +21,15 @@ digest you intend to run:
 
 ```bash
 kubectl set image -n durable-workflow deploy/durable-workflow-server \
-  server=durableworkflow/server:2.5.9
+  server=durableworkflow/server:2.5.10
 kubectl set image -n durable-workflow deploy/durable-workflow-worker \
-  worker=durableworkflow/server:2.5.9
+  worker=durableworkflow/server:2.5.10
 kubectl set image -n durable-workflow cronjob/durable-workflow-scheduler \
-  scheduler=durableworkflow/server:2.5.9
+  scheduler=durableworkflow/server:2.5.10
 ```
 
 GitHub Container Registry publishes the same release line at
-`ghcr.io/durable-workflow/server:2.5.9`. Digest pinning is preferred for strict
+`ghcr.io/durable-workflow/server:2.5.10`. Digest pinning is preferred for strict
 change control.
 
 The manifests expect you to provide:
diff --git a/k8s/helm/durable-workflow/Chart.yaml b/k8s/helm/durable-workflow/Chart.yaml
index 6a55f204a..fe452dbd2 100644
--- a/k8s/helm/durable-workflow/Chart.yaml
+++ b/k8s/helm/durable-workflow/Chart.yaml
@@ -5,11 +5,11 @@ type: application
 # The chart's own semver version. Bumped on every chart release; treated as
 # independent of the server image version (appVersion). Breaking-change rules
 # for this version live in docs/helm-upgrading.md alongside the chart.
-version: 0.1.146
+version: 0.1.147
 # The immutable Durable Workflow Server identity this chart release packages.
 # The onboarding default in values.yaml and appVersion are generated from the
 # checked-in source release record.
-appVersion: "2.5.9"
+appVersion: "2.5.10"
 kubeVersion: ">=1.27.0-0"
 home: https://durable-workflow.github.io/docs/2.0/deployment
 sources:
@@ -30,7 +30,7 @@ annotations:
   # exact commit that most recently changed the packaged chart.
   org.opencontainers.image.source: https://github.com/durable-workflow/server
   dev.durable-workflow.source-revision: "unreleased"
-  dev.durable-workflow.image-reference: "docker.io/durableworkflow/server:2.5.9"
+  dev.durable-workflow.image-reference: "docker.io/durableworkflow/server:2.5.10"
   artifacthub.io/license: MIT
   artifacthub.io/category: integration-delivery
   # Free-form changelog for the current chart release shown by Artifact Hub.
diff --git a/k8s/helm/durable-workflow/README.md b/k8s/helm/durable-workflow/README.md
index 5868eeb4c..8336a425d 100644
--- a/k8s/helm/durable-workflow/README.md
+++ b/k8s/helm/durable-workflow/README.md
@@ -63,7 +63,7 @@ helm install durable-workflow ./k8s/helm/durable-workflow \
 
 ```yaml
 image:
-  tag: "2.5.9"
+  tag: "2.5.10"
   # Pin a digest in production:
   # digest: "sha256:abc123..."
   # memoPayloadStorage: "raw-json-v1" # Required for a digest or custom image.
diff --git a/k8s/helm/durable-workflow/ci/existing-secrets-values.yaml b/k8s/helm/durable-workflow/ci/existing-secrets-values.yaml
index 856f2f794..9275d4955 100644
--- a/k8s/helm/durable-workflow/ci/existing-secrets-values.yaml
+++ b/k8s/helm/durable-workflow/ci/existing-secrets-values.yaml
@@ -1,7 +1,7 @@
 # CI fixture: GitOps / externally-managed-secret path. The chart consumes
 # existing Secrets and renders no Secret resources of its own.
 image:
-  tag: "2.5.9"
+  tag: "2.5.10"
 
 externalDatabase:
   connection: pgsql
diff --git a/k8s/helm/durable-workflow/ci/ingress-and-hpa-values.yaml b/k8s/helm/durable-workflow/ci/ingress-and-hpa-values.yaml
index 9a3362784..f0340b43e 100644
--- a/k8s/helm/durable-workflow/ci/ingress-and-hpa-values.yaml
+++ b/k8s/helm/durable-workflow/ci/ingress-and-hpa-values.yaml
@@ -1,6 +1,6 @@
 # CI fixture: ingress + autoscaling enabled. Exercises optional templates.
 image:
-  tag: "2.5.9"
+  tag: "2.5.10"
 
 externalDatabase:
   connection: mysql
diff --git a/k8s/helm/durable-workflow/ci/inline-secrets-values.yaml b/k8s/helm/durable-workflow/ci/inline-secrets-values.yaml
index 2b2773eea..daf2964c1 100644
--- a/k8s/helm/durable-workflow/ci/inline-secrets-values.yaml
+++ b/k8s/helm/durable-workflow/ci/inline-secrets-values.yaml
@@ -2,7 +2,7 @@
 # chart's render path is exercised end-to-end. Real deployments should use
 # existingSecret instead.
 image:
-  tag: "2.5.9"
+  tag: "2.5.10"
 
 externalDatabase:
   connection: mysql
diff --git a/k8s/helm/durable-workflow/templates/_helpers.tpl b/k8s/helm/durable-workflow/templates/_helpers.tpl
index fe2b1dd98..a1d955674 100644
--- a/k8s/helm/durable-workflow/templates/_helpers.tpl
+++ b/k8s/helm/durable-workflow/templates/_helpers.tpl
@@ -88,7 +88,7 @@ resolved by an explicit capability declaration or an existing workload marker.
 {{- define "durable-workflow.memoPayloadStorageForImage" -}}
 {{- $image := toString . -}}
 {{- $normalized := regexReplaceAll "^index\\.docker\\.io/" $image "docker.io/" -}}
-{{- if eq $normalized "docker.io/durableworkflow/server:2.5.9" -}}
+{{- if eq $normalized "docker.io/durableworkflow/server:2.5.10" -}}
 dual-v1
 {{- else if regexMatch "^docker\\.io/durableworkflow/server:2\\.0\\.0-rc\\.[0-9]+$" $normalized -}}
 {{- $releaseCandidate := atoi (regexFind "[0-9]+$" $normalized) -}}
diff --git a/k8s/helm/durable-workflow/values.yaml b/k8s/helm/durable-workflow/values.yaml
index fe3fa4ae7..59d970b12 100644
--- a/k8s/helm/durable-workflow/values.yaml
+++ b/k8s/helm/durable-workflow/values.yaml
@@ -21,7 +21,7 @@ image:
   registry: docker.io
   repository: durableworkflow/server
   # Generated by scripts/ci/sync-source-release.mjs. Do not edit this default.
-  tag: "2.5.9"
+  tag: "2.5.10"
   # Optional digest pin. When set, takes precedence over tag for change control.
   # Example: "sha256:abc123..."
   digest: ""
diff --git a/k8s/helm/examples/values-dev.yaml b/k8s/helm/examples/values-dev.yaml
index f32df0d6c..93ebc3383 100644
--- a/k8s/helm/examples/values-dev.yaml
+++ b/k8s/helm/examples/values-dev.yaml
@@ -3,7 +3,7 @@
 # shape in production.
 
 image:
-  tag: "2.5.9"
+  tag: "2.5.10"
 
 externalDatabase:
   connection: mysql
diff --git a/k8s/helm/examples/values-external-secrets-operator.yaml b/k8s/helm/examples/values-external-secrets-operator.yaml
index 0979de749..7cf59edbf 100644
--- a/k8s/helm/examples/values-external-secrets-operator.yaml
+++ b/k8s/helm/examples/values-external-secrets-operator.yaml
@@ -5,7 +5,7 @@
 # concern.
 
 image:
-  tag: "2.5.9"
+  tag: "2.5.10"
 
 externalDatabase:
   connection: pgsql
diff --git a/k8s/helm/examples/values-production-existing-secrets.yaml b/k8s/helm/examples/values-production-existing-secrets.yaml
index 6a6b16185..a18f92f84 100644
--- a/k8s/helm/examples/values-production-existing-secrets.yaml
+++ b/k8s/helm/examples/values-production-existing-secrets.yaml
@@ -10,7 +10,7 @@ image:
   repository: durable-workflow/server
   # Pin a digest in production for change-control auditability.
   digest: ""    # e.g. "sha256:abc123..."
-  tag: "2.5.9"
+  tag: "2.5.10"
 
 externalDatabase:
   connection: pgsql
diff --git a/k8s/migration-job.yaml b/k8s/migration-job.yaml
index f58a60172..25c74c508 100644
--- a/k8s/migration-job.yaml
+++ b/k8s/migration-job.yaml
@@ -13,7 +13,7 @@ spec:
       restartPolicy: OnFailure
       containers:
         - name: migrate
-          image: durableworkflow/server:2.5.9
+          image: durableworkflow/server:2.5.10
           command: ["server-entrypoint"]
           args: ["server-bootstrap"]
           envFrom:
diff --git a/k8s/scheduler-cronjob.yaml b/k8s/scheduler-cronjob.yaml
index ae8cf6d99..cba1a1dca 100644
--- a/k8s/scheduler-cronjob.yaml
+++ b/k8s/scheduler-cronjob.yaml
@@ -24,7 +24,7 @@ spec:
           restartPolicy: Never
           containers:
             - name: scheduler
-              image: durableworkflow/server:2.5.9
+              image: durableworkflow/server:2.5.10
               command: ["server-entrypoint"]
               args:
                 - sh
diff --git a/k8s/secret.yaml b/k8s/secret.yaml
index 3cf9e45a5..aabb06674 100644
--- a/k8s/secret.yaml
+++ b/k8s/secret.yaml
@@ -12,7 +12,7 @@ metadata:
     app.kubernetes.io/name: durable-workflow
 data:
   APP_NAME: "Durable Workflow Server"
-  APP_VERSION: "2.5.9"
+  APP_VERSION: "2.5.10"
   APP_ENV: production
   APP_DEBUG: "false"
   DB_CONNECTION: mysql
diff --git a/k8s/server-deployment.yaml b/k8s/server-deployment.yaml
index d8ee6458d..fbb33be07 100644
--- a/k8s/server-deployment.yaml
+++ b/k8s/server-deployment.yaml
@@ -23,7 +23,7 @@ spec:
     spec:
       containers:
         - name: server
-          image: durableworkflow/server:2.5.9
+          image: durableworkflow/server:2.5.10
           ports:
             - containerPort: 8080
               name: http
diff --git a/k8s/worker-deployment.yaml b/k8s/worker-deployment.yaml
index f2c697da8..7a301aeb7 100644
--- a/k8s/worker-deployment.yaml
+++ b/k8s/worker-deployment.yaml
@@ -19,7 +19,7 @@ spec:
     spec:
       containers:
         - name: worker
-          image: durableworkflow/server:2.5.9
+          image: durableworkflow/server:2.5.10
           command: ["server-entrypoint"]
           args: ["php", "artisan", "queue:work", "--sleep=1", "--tries=3", "--max-time=3600"]
           envFrom:
diff --git a/resources/platform-protocol-specs/worker-protocol-api.openapi.yaml b/resources/platform-protocol-specs/worker-protocol-api.openapi.yaml
index 3da1eb062..fba5c36b2 100644
--- a/resources/platform-protocol-specs/worker-protocol-api.openapi.yaml
+++ b/resources/platform-protocol-specs/worker-protocol-api.openapi.yaml
@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: durable-workflow.v2.worker-protocol-api
-  version: "48"
+  version: "49"
   summary: Durable Workflow worker-plane HTTP+JSON API
   description: >
     Normative OpenAPI specification for the worker-plane HTTP+JSON API:
@@ -1866,6 +1866,24 @@ components:
         workflow_task_attempt: { type: integer, minimum: 1 }
         lease_owner: { type: string, minLength: 1 }
         lease_expires_at: { type: string, format: date-time }
+        sticky_worker_id:
+          type: [string, "null"]
+          description: Process identity holding this run's optional sticky affinity.
+          x-durable-workflow-minimum-protocol-version: "1.18"
+        sticky_until:
+          type: [string, "null"]
+          format: date-time
+          description: Affinity expiry. Cache loss before expiry still requires cold replay.
+          x-durable-workflow-minimum-protocol-version: "1.18"
+        sticky_replay_mode:
+          type: [string, "null"]
+          enum: [cold_replay, sticky_hit_expected, forced_cold_replay, null]
+          description: >-
+            Authoritative mode for the current lease. A warm hint requires a valid
+            local prefix. PHP SDKs before 2.2.0 receive null to preserve full replay
+            because their sticky fallback rejects a valid StartAccepted prefix.
+            History, pagination, affinity routing and lease identity are unchanged.
+          x-durable-workflow-minimum-protocol-version: "1.18"
         history_events: { type: array, items: { $ref: "#/components/schemas/WorkerHistoryEvent" } }
         cancellation_request:
           $ref: "#/components/schemas/CooperativeCancellationRequest"
diff --git a/resources/release/source-release.json b/resources/release/source-release.json
index f4f99179b..4ec915784 100644
--- a/resources/release/source-release.json
+++ b/resources/release/source-release.json
@@ -1,9 +1,9 @@
 {
   "schema": "durable-workflow.server.source-release/v1",
   "server": {
-    "version": "2.5.9"
+    "version": "2.5.10"
   },
   "helm_chart": {
-    "version": "0.1.146"
+    "version": "0.1.147"
   }
 }
diff --git a/scripts/k8s-kind-smoke.sh b/scripts/k8s-kind-smoke.sh
index ca5b637f7..60c934f31 100755
--- a/scripts/k8s-kind-smoke.sh
+++ b/scripts/k8s-kind-smoke.sh
@@ -7,7 +7,7 @@ cluster="${K8S_SMOKE_CLUSTER:-durable-workflow-server-smoke}"
 image="${K8S_SMOKE_IMAGE:-durableworkflow/server:k8s-smoke}"
 # Generated by scripts/ci/sync-source-release.mjs so the smoke replaces the
 # same default shipped by the public manifests.
-manifest_image="durableworkflow/server:2.5.9"
+manifest_image="durableworkflow/server:2.5.10"
 kind_node_image="${K8S_SMOKE_KIND_NODE_IMAGE:-kindest/node:v1.29.4}"
 artifact_dir="${K8S_SMOKE_ARTIFACT_DIR:-/tmp/durable-workflow-k8s-kind-smoke-artifacts}"
 rendered_dir="${artifact_dir}/rendered-manifests"
diff --git a/tests/Feature/WorkflowWorkerProtocolTest.php b/tests/Feature/WorkflowWorkerProtocolTest.php
index 425129312..cb0f5761b 100644
--- a/tests/Feature/WorkflowWorkerProtocolTest.php
+++ b/tests/Feature/WorkflowWorkerProtocolTest.php
@@ -15,6 +15,7 @@
 use Illuminate\Support\Carbon;
 use Illuminate\Support\Facades\Queue;
 use Mockery\MockInterface;
+use PHPUnit\Framework\Attributes\DataProvider;
 use Tests\Fixtures\ExternalGreetingWorkflow;
 use Tests\Fixtures\InteractiveCommandWorkflow;
 use Tests\TestCase;
@@ -25,6 +26,7 @@
 use Workflow\V2\Enums\TaskStatus;
 use Workflow\V2\Enums\TaskType;
 use Workflow\V2\Exceptions\StructuralLimitExceededException;
+use Workflow\V2\Jobs\RunTimerTask;
 use Workflow\V2\Models\ActivityAttempt;
 use Workflow\V2\Models\ActivityExecution;
 use Workflow\V2\Models\WorkflowChildCall;
@@ -986,8 +988,24 @@ public function test_local_activity_completion_uses_negotiated_nested_object_str
         }
     }
 
-    public function test_sticky_claim_requires_exact_identity_and_persists_only_as_an_optimization(): void
+    public static function stickyReplayWorkerProfiles(): array
     {
+        return [
+            'legacy PHP' => ['php', 'durable-workflow-php/2.1.5', false],
+            'legacy PHP with v prefix' => ['php', 'durable-workflow-php/v2.1.6', false],
+            'fixed PHP' => ['php', 'durable-workflow-php/2.2.0', true],
+            'current PHP' => ['php', 'durable-workflow-php/2.2.4', true],
+            'source capability manifest' => ['php', 'durable-workflow-php/test', true],
+            'Python' => ['python', 'durable-workflow-python/2.5.0', true],
+        ];
+    }
+
+    #[DataProvider('stickyReplayWorkerProfiles')]
+    public function test_sticky_claim_requires_exact_identity_and_persists_only_as_an_optimization(
+        string $runtime,
+        string $sdkVersion,
+        bool $expectsReplayHint,
+    ): void {
         Queue::fake();
         $this->configureWorkflowTypes();
         $this->createNamespace('default', 'Default namespace');
@@ -1012,8 +1030,8 @@ public function test_sticky_claim_requires_exact_identity_and_persists_only_as_a
         $this->withHeaders($this->workerHeaders())->postJson('/api/worker/register', [
             'worker_id' => 'php-sticky-worker',
             'task_queue' => 'portable-affinity',
-            'runtime' => 'php',
-            'sdk_version' => 'durable-workflow-php/test',
+            'runtime' => $runtime,
+            'sdk_version' => $sdkVersion,
             'build_id' => 'build-a',
             'supported_workflow_types' => ['tests.external-greeting-workflow'],
             'capabilities' => $capabilities,
@@ -1024,7 +1042,12 @@ public function test_sticky_claim_requires_exact_identity_and_persists_only_as_a
             'worker_id' => 'php-sticky-worker',
             'task_queue' => 'portable-affinity',
             'build_id' => 'build-a',
-        ])->assertOk();
+            'history_page_size' => 1,
+        ])->assertOk()
+            ->assertJsonPath('task.sticky_worker_id', null)
+            ->assertJsonPath('task.sticky_until', null)
+            ->assertJsonPath('task.sticky_replay_mode', $expectsReplayHint ? StickyExecution::MODE_COLD_REPLAY : null);
+        $this->assertSame('StartAccepted', $poll->json('task.history_events.0.event_type'));
         $taskId = (string) $poll->json('task.task_id');
 
         $this->withHeaders($this->workerHeaders())
@@ -1053,6 +1076,42 @@ public function test_sticky_claim_requires_exact_identity_and_persists_only_as_a
                 ->firstOrFail()
                 ->process_metrics['sticky_cache'],
         );
+
+        $timer = WorkflowTask::query()->where('workflow_run_id', $runId)
+            ->where('task_type', TaskType::Timer)->firstOrFail();
+        $this->travel(6)->seconds();
+        $this->app->call([new RunTimerTask($timer->id), 'handle']);
+        $body = [
+            'worker_id' => 'php-sticky-worker',
+            'task_queue' => 'portable-affinity',
+            'build_id' => 'build-a',
+            'history_page_size' => 1,
+            'poll_request_id' => 'sticky-warm-poll',
+        ];
+        $warm = $this->withHeaders($this->workerHeaders())->postJson('/api/worker/workflow-tasks/poll', $body)
+            ->assertOk()
+            ->assertJsonPath('task.sticky_worker_id', 'php-sticky-worker')
+            ->assertJsonPath('task.sticky_replay_mode', $expectsReplayHint ? StickyExecution::MODE_STICKY_HIT_EXPECTED : null);
+        $this->assertNotNull($warm->json('task.sticky_until'));
+        $this->assertNotNull($warm->json('task.next_history_page_token'));
+        $this->withHeaders($this->workerHeaders())->postJson('/api/worker/workflow-tasks/poll', $body)
+            ->assertOk()
+            ->assertJsonPath('task.task_id', $warm->json('task.task_id'))
+            ->assertJsonPath('task.workflow_task_attempt', $warm->json('task.workflow_task_attempt'))
+            ->assertJsonPath('task.sticky_worker_id', 'php-sticky-worker')
+            ->assertJsonPath('task.sticky_until', $warm->json('task.sticky_until'))
+            ->assertJsonPath('task.sticky_replay_mode', $expectsReplayHint ? StickyExecution::MODE_STICKY_HIT_EXPECTED : null);
+
+        // Losing the holder lease and affinity TTL keeps the original durable run.
+        WorkflowTask::query()->whereKey($warm->json('task.task_id'))->update([
+            'status' => TaskStatus::Ready, 'lease_owner' => null, 'lease_expires_at' => null,
+            'sticky_until' => now()->subSecond(),
+        ]);
+        $body['poll_request_id'] = 'sticky-expired-poll';
+        $this->withHeaders($this->workerHeaders())->postJson('/api/worker/workflow-tasks/poll', $body)
+            ->assertOk()
+            ->assertJsonPath('task.run_id', $runId)
+            ->assertJsonPath('task.sticky_replay_mode', $expectsReplayHint ? StickyExecution::MODE_FORCED_COLD_REPLAY : null);
     }
 
     public function test_worker_heartbeat_is_scoped_to_the_resolved_namespace(): void
diff --git a/tests/Unit/WorkerProtocolOpenApiContractTest.php b/tests/Unit/WorkerProtocolOpenApiContractTest.php
index 1a878c08e..2e1b1467a 100644
--- a/tests/Unit/WorkerProtocolOpenApiContractTest.php
+++ b/tests/Unit/WorkerProtocolOpenApiContractTest.php
@@ -146,6 +146,15 @@ public function test_worker_lifecycle_and_poll_routes_describe_unknown_database_
 
     public function test_portable_worker_affinity_is_machine_described_at_protocol_1_18(): void
     {
+        $task = $this->spec['components']['schemas']['WorkflowTask'];
+        foreach (['sticky_worker_id', 'sticky_until', 'sticky_replay_mode'] as $field) {
+            $this->assertSame(['string', 'null'], $task['properties'][$field]['type']);
+            $this->assertSame('1.18', $task['properties'][$field]['x-durable-workflow-minimum-protocol-version']);
+        }
+        $this->assertSame(
+            ['cold_replay', 'sticky_hit_expected', 'forced_cold_replay', null],
+            $task['properties']['sticky_replay_mode']['enum'],
+        );
         $contract = $this->spec['x-durable-workflow-portable-worker-affinity-contract'];
         $this->assertSame('1.18', $contract['minimum_protocol_version']);
         $this->assertSame(