From e3a3fa7108391000b9be0b9e2aed35437c2dc421 Mon Sep 17 00:00:00 2001
From: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>
Date: Sun, 20 Sep 2026 11:22:49 -0500
Subject: [PATCH] fix(plugin): forward Promise tool cancellation (#50190)

---
 .../core/test/plugin/promise-tool.test.ts     | 55 +++++++++++++++++++
 packages/plugin/src/promise/adapter.ts        | 14 +++--
 packages/plugin/src/promise/tool.ts           |  1 +
 .../src/docs/content/build/plugins/index.mdx  | 10 ++++
 4 files changed, 74 insertions(+), 6 deletions(-)
 create mode 100644 packages/core/test/plugin/promise-tool.test.ts

diff --git a/packages/core/test/plugin/promise-tool.test.ts b/packages/core/test/plugin/promise-tool.test.ts
new file mode 100644
index 00000000000..b312b348d16
--- /dev/null
+++ b/packages/core/test/plugin/promise-tool.test.ts
@@ -0,0 +1,55 @@
+import { expect } from "bun:test"
+import { Agent } from "@opencode/core/agent"
+import { Plugin } from "@opencode/core/plugin"
+import { PluginHost } from "@opencode/core/plugin/host"
+import { PluginPromise } from "@opencode/core/plugin/promise"
+import { Tool } from "@opencode/core/tool"
+import { Session } from "@opencode/schema/session"
+import { SessionMessage } from "@opencode/schema/session-message"
+import { Cause, Deferred, Effect, Exit, Fiber } from "effect"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+it.live("Promise tool executors receive interruption through their AbortSignal", () =>
+  Effect.gen(function* () {
+    const plugins = yield* Plugin.Service
+    const tools = yield* Tool.Service
+    const started = yield* Deferred.make<AbortSignal>()
+    yield* PluginPromise.fromPromise({
+      id: "cancel-tool",
+      async setup(context) {
+        await context.tool.transform((editor) =>
+          editor.add({
+            name: "wait",
+            description: "Wait until cancelled",
+            input: { type: "object", properties: {}, additionalProperties: false },
+            options: { codemode: false },
+            execute: (_input, tool) =>
+              new Promise<never>((_resolve, reject) => {
+                tool.signal.addEventListener("abort", () => reject(new Error("cancelled")), { once: true })
+                Effect.runSync(Deferred.succeed(started, tool.signal))
+              }),
+          }),
+        )
+      },
+    }).effect(yield* PluginHost.make(plugins))
+
+    const snapshot = yield* tools.snapshot()
+    const fiber = yield* snapshot
+      .execute({
+        sessionID: Session.ID.make("ses_promise_tool_cancel"),
+        agent: Agent.ID.make("build"),
+        messageID: SessionMessage.ID.make("msg_promise_tool_cancel"),
+        call: { type: "tool-call", id: "call_promise_tool_cancel", name: "wait", input: {} },
+      })
+      .pipe(Effect.forkScoped)
+    const signal = yield* Deferred.await(started)
+    expect(signal.aborted).toBe(false)
+    yield* Fiber.interrupt(fiber)
+    const exit = yield* Fiber.await(fiber)
+    expect(signal.aborted).toBe(true)
+    expect(Exit.isFailure(exit) && Cause.hasInterruptsOnly(exit.cause)).toBe(true)
+  }),
+)
diff --git a/packages/plugin/src/promise/adapter.ts b/packages/plugin/src/promise/adapter.ts
index 7fd49d85ab5..39f33866383 100644
--- a/packages/plugin/src/promise/adapter.ts
+++ b/packages/plugin/src/promise/adapter.ts
@@ -250,12 +250,13 @@ export function fromPromise(plugin: Plugin) {
 
         const promiseExecutor =
           (execute: Tool.Info["execute"]): Info["execute"] =>
-          (input, context) =>
-            run(
+          (input, tool) =>
+            Effect.runPromiseWith(context)(
               execute(input, {
-                ...context,
-                progress: (update) => Effect.promise(() => context.progress(update)),
+                ...tool,
+                progress: (update) => Effect.promise(() => tool.progress(update)),
               }),
+              { signal: tool.signal },
             )
 
         const adaptApiMethod = <PromiseMethod>(
@@ -612,9 +613,10 @@ function attempt<A>(evaluate: (signal: AbortSignal) => PromiseLike<A>) {
 type RuntimeSchema = Schema.Codec<unknown, unknown>
 
 const executePromiseTool = (tool: Info, input: any, context: Tool.Context) =>
-  Effect.promise(() =>
+  Effect.promise((signal) =>
     tool.execute(input, {
       ...context,
-      progress: (update) => Effect.runPromise(context.progress(update)),
+      signal,
+      progress: (update) => Effect.runPromise(context.progress(update), { signal }),
     }),
   )
diff --git a/packages/plugin/src/promise/tool.ts b/packages/plugin/src/promise/tool.ts
index 4f6788b4243..5eb814e3980 100644
--- a/packages/plugin/src/promise/tool.ts
+++ b/packages/plugin/src/promise/tool.ts
@@ -9,6 +9,7 @@ import type { Types } from "effect"
 import type { Hooks, Transform } from "./registration.js"
 
 export interface ToolContext extends Omit<Tool.Context, "progress"> {
+  readonly signal: AbortSignal
   readonly progress: (update: Tool.Metadata) => Promise<void>
 }
 
diff --git a/services/www/src/docs/content/build/plugins/index.mdx b/services/www/src/docs/content/build/plugins/index.mdx
index 0e4d35bdc2c..8a1507c9dbe 100644
--- a/services/www/src/docs/content/build/plugins/index.mdx
+++ b/services/www/src/docs/content/build/plugins/index.mdx
@@ -927,6 +927,16 @@ const registration = await ctx.tool.transform((editor) => {
 })
 ```
 
+Promise tool executors receive `tool.signal`. Pass it to cancellable work such as `fetch` so stopping the Session also
+stops the underlying operation.
+
+```ts
+execute: async ({ url }, tool) => {
+  const response = await fetch(url, { signal: tool.signal })
+  return { content: await response.text() }
+}
+```
+
 Call `reload()` after changing source data captured by the callback. Reload replays the active transforms without
 changing their order; it does not rerun plugin setup.