From d9dcaaf0c6dbfed6906b00bbd92712e054978609 Mon Sep 17 00:00:00 2001
From: Vaggeilis Yfantis <vaggelisyfantis@gmail.com>
Date: Sun, 15 Feb 2026 02:00:15 +0200
Subject: [PATCH 1/2] feat: Cancel workflow via the client with workflow id

---
 packages/openworkflow/client.test.ts | 27 +++++++++++++++++++++++++++
 packages/openworkflow/client.ts      | 14 ++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/packages/openworkflow/client.test.ts b/packages/openworkflow/client.test.ts
index 0e154cb8..cb5e50db 100644
--- a/packages/openworkflow/client.test.ts
+++ b/packages/openworkflow/client.test.ts
@@ -412,6 +412,33 @@ describe("OpenWorkflow", () => {
     expect(workflowRun?.finishedAt).not.toBeNull();
   });
 
+  test("cancels workflow run via client by ID", async () => {
+    const backend = await createBackend();
+    const client = new OpenWorkflow({ backend });
+
+    const workflow = client.defineWorkflow({ name: "cancel-test" }, noopFn);
+    const handle = await workflow.run({ value: 1 });
+
+    await client.cancelWorkflowRun(handle.workflowRun.id);
+
+    const workflowRun = await backend.getWorkflowRun({
+      workflowRunId: handle.workflowRun.id,
+    });
+    expect(workflowRun?.status).toBe("canceled");
+    expect(workflowRun?.finishedAt).not.toBeNull();
+  });
+
+  test("throws when canceling a non-existent workflow run", async () => {
+    const backend = await createBackend();
+    const client = new OpenWorkflow({ backend });
+
+    const nonExistentId = randomUUID();
+
+    await expect(
+      client.cancelWorkflowRun(nonExistentId),
+    ).rejects.toThrow(`Workflow run ${nonExistentId} does not exist`);
+  });
+
   describe("defineWorkflowSpec / implementWorkflow API", () => {
     test("defineWorkflowSpec returns a spec that can be used to schedule runs", async () => {
       const backend = await createBackend();
diff --git a/packages/openworkflow/client.ts b/packages/openworkflow/client.ts
index 6be212b1..ebdd89e1 100644
--- a/packages/openworkflow/client.ts
+++ b/packages/openworkflow/client.ts
@@ -157,6 +157,20 @@ export class OpenWorkflow {
 
     return new RunnableWorkflow(this, workflow);
   }
+
+  /**
+   * Cancels the workflow run with the given ID. Only workflow runs in pending, running, or sleeping
+   * status can be canceled.
+   * @param workflowRunId - The ID of the workflow run to cancel
+   * @returns Promise<void>
+   * @example
+   * ```ts
+   * await ow.cancelWorkflowRun("123");
+   * ```
+   */
+  async cancelWorkflowRun(workflowRunId: string): Promise<void> {
+    await this.backend.cancelWorkflowRun({ workflowRunId });
+  }
 }
 
 /**

From eec63c3ffe6697215578527f0341d1f94f0b0e49 Mon Sep 17 00:00:00 2001
From: Vaggeilis Yfantis <vaggelisyfantis@gmail.com>
Date: Sun, 15 Feb 2026 16:57:50 +0200
Subject: [PATCH 2/2] chore: Fix CI issues

---
 packages/openworkflow/client.test.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/openworkflow/client.test.ts b/packages/openworkflow/client.test.ts
index cb5e50db..533aeab7 100644
--- a/packages/openworkflow/client.test.ts
+++ b/packages/openworkflow/client.test.ts
@@ -434,9 +434,9 @@ describe("OpenWorkflow", () => {
 
     const nonExistentId = randomUUID();
 
-    await expect(
-      client.cancelWorkflowRun(nonExistentId),
-    ).rejects.toThrow(`Workflow run ${nonExistentId} does not exist`);
+    await expect(client.cancelWorkflowRun(nonExistentId)).rejects.toThrow(
+      `Workflow run ${nonExistentId} does not exist`,
+    );
   });
 
   describe("defineWorkflowSpec / implementWorkflow API", () => {