diff --git a/apps/webapp/app/routes/resources.runs.$runParam.ts b/apps/webapp/app/routes/resources.runs.$runParam.ts
index 7b116b31c3..044f25e372 100644
--- a/apps/webapp/app/routes/resources.runs.$runParam.ts
+++ b/apps/webapp/app/routes/resources.runs.$runParam.ts
@@ -189,6 +189,7 @@ export const loader = async ({ request, params }: LoaderFunctionArgs) => {
       version: run.lockedToVersion?.version,
       parentTaskRunId: run.parentTaskRun?.friendlyId ?? undefined,
       rootTaskRunId: run.rootTaskRun?.friendlyId ?? undefined,
+      concurrencyKey: run.concurrencyKey ?? undefined,
     },
     queue: {
       name: run.queue,
diff --git a/apps/webapp/app/v3/marqs/sharedQueueConsumer.server.ts b/apps/webapp/app/v3/marqs/sharedQueueConsumer.server.ts
index 075732544c..f158020a37 100644
--- a/apps/webapp/app/v3/marqs/sharedQueueConsumer.server.ts
+++ b/apps/webapp/app/v3/marqs/sharedQueueConsumer.server.ts
@@ -1639,6 +1639,7 @@ export const AttemptForExecutionGetPayload = {
         baseCostInCents: true,
         maxDurationInSeconds: true,
         tags: true,
+        concurrencyKey: true,
       },
     },
     queue: {
@@ -1722,6 +1723,7 @@ class SharedQueueTasks {
         baseCostInCents: taskRun.baseCostInCents,
         metadata,
         maxDuration: taskRun.maxDurationInSeconds ?? undefined,
+        concurrencyKey: taskRun.concurrencyKey ?? undefined,
       },
       queue: {
         id: queue.friendlyId,
diff --git a/apps/webapp/app/v3/services/createTaskRunAttempt.server.ts b/apps/webapp/app/v3/services/createTaskRunAttempt.server.ts
index df5e4e2b74..e49b9dce0c 100644
--- a/apps/webapp/app/v3/services/createTaskRunAttempt.server.ts
+++ b/apps/webapp/app/v3/services/createTaskRunAttempt.server.ts
@@ -220,6 +220,7 @@ export class CreateTaskRunAttemptService extends BaseService {
           version: lockedBy.worker.version,
           metadata,
           maxDuration: taskRun.maxDurationInSeconds ?? undefined,
+          concurrencyKey: taskRun.concurrencyKey ?? undefined,
         },
         queue: {
           id: queue.friendlyId,
diff --git a/packages/core/src/v3/schemas/common.ts b/packages/core/src/v3/schemas/common.ts
index 2928995606..129d5bfe48 100644
--- a/packages/core/src/v3/schemas/common.ts
+++ b/packages/core/src/v3/schemas/common.ts
@@ -222,6 +222,7 @@ export const TaskRun = z.object({
   /** The priority of the run. Wih a value of 10 it will be dequeued before runs that were triggered 9 seconds before it (assuming they had no priority set).  */
   priority: z.number().optional(),
   baseCostInCents: z.number().optional(),
+  concurrencyKey: z.string().optional(),
 
   parentTaskRunId: z.string().optional(),
   rootTaskRunId: z.string().optional(),
@@ -375,6 +376,7 @@ export const V3TaskRun = z.object({
   durationMs: z.number(),
   costInCents: z.number(),
   baseCostInCents: z.number(),
+  concurrencyKey: z.string().optional(),
 });
 
 export type V3TaskRun = z.infer<typeof V3TaskRun>;
diff --git a/packages/core/test/taskExecutor.test.ts b/packages/core/test/taskExecutor.test.ts
index 229a952fff..0db0fe9e55 100644
--- a/packages/core/test/taskExecutor.test.ts
+++ b/packages/core/test/taskExecutor.test.ts
@@ -944,6 +944,28 @@ describe("TaskExecutor", () => {
     });
   });
 
+  test("should include concurrencyKey in task context", async () => {
+    let capturedContext: any;
+
+    const task = {
+      id: "test-task",
+      fns: {
+        run: async (payload: any, params: RunFnParams<any>) => {
+          capturedContext = params.ctx;
+          return {
+            output: "test-output",
+          };
+        },
+      },
+    };
+
+    const result = await executeTask(task, { test: "data" }, undefined, undefined, "user-123");
+
+    expect(result.result.ok).toBe(true);
+    expect(capturedContext).toBeDefined();
+    expect(capturedContext.run.concurrencyKey).toBe("user-123");
+  });
+
   test("should handle middleware errors correctly", async () => {
     const executionOrder: string[] = [];
     const expectedError = new Error("Middleware error");
@@ -1846,7 +1868,8 @@ function executeTask(
   task: TaskMetadataWithFunctions,
   payload: any,
   signal?: AbortSignal,
-  retrySettings?: RetryOptions
+  retrySettings?: RetryOptions,
+  concurrencyKey?: string
 ) {
   const tracingSDK = new TracingSDK({
     url: "http://localhost:4318",
@@ -1904,6 +1927,7 @@ function executeTask(
       baseCostInCents: 0,
       priority: 0,
       maxDuration: 1000,
+      concurrencyKey: concurrencyKey,
     },
     machine: {
       name: "micro",