diff --git a/apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.test.ts b/apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.test.ts
index 07c3bd731633f..094b5eb14181e 100644
--- a/apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.test.ts
+++ b/apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.test.ts
@@ -4433,6 +4433,140 @@ describe("AcpAdapterV2", () => {
     }).pipe(Effect.provide(layerTest), Effect.scoped),
   );
 
+  it.effect.each([
+    {
+      label: "answers Always allow with the agent's allow-always option",
+      options: [
+        { optionId: "allow-once", name: "Allow once", kind: "allow_once" },
+        { optionId: "allow-always", name: "Always allow", kind: "allow_always" },
+        { optionId: "reject-once", name: "Reject", kind: "reject_once" },
+      ],
+      optionId: "allow-always",
+    },
+    {
+      label: "answers Always allow with allow-once when the agent offers no allow-always option",
+      options: [
+        { optionId: "allow-once", name: "Allow once", kind: "allow_once" },
+        { optionId: "reject-once", name: "Reject", kind: "reject_once" },
+      ],
+      optionId: "allow-once",
+    },
+  ] as const)("$label", ({ options, optionId }) =>
+    Effect.gen(function* () {
+      const childProcessSpawner = yield* ChildProcessSpawner.ChildProcessSpawner;
+      const path = yield* Path.Path;
+      const selfInvocation = yield* resolveSelfInvocation();
+      const mockAgentPath = yield* path.fromFileUrl(
+        new URL("../../../scripts/acp-mock-agent.ts", import.meta.url),
+      );
+      type RuntimeService = AcpSessionRuntime.AcpSessionRuntime["Service"];
+      let requestPermission: Parameters<RuntimeService["handleRequestPermission"]>[0] | undefined;
+      let runtimeInput: AcpAdapterV2RuntimeInput | undefined;
+      const makeRuntime = makeMockRuntime({
+        childProcessSpawner,
+        mockAgentPath,
+        environment: { T3_ACP_HANG_PROMPT_FOREVER: "1" },
+        wrapRuntime: (runtime) => ({
+          ...runtime,
+          handleRequestPermission: (handler) =>
+            Effect.sync(() => {
+              requestPermission = handler;
+            }).pipe(Effect.andThen(runtime.handleRequestPermission(handler))),
+        }),
+      });
+      const instanceId = ProviderInstanceId.make("acp-test-always-allow");
+      const adapter = yield* makeAcpAdapterV2({
+        instanceId,
+        flavor: {
+          driver: ACP_TEST_DRIVER,
+          capabilities: AcpProviderCapabilitiesV2,
+          interruptPromptOnCancel: true,
+          makeRuntime: (input) =>
+            Effect.sync(() => {
+              runtimeInput = input;
+            }).pipe(Effect.andThen(makeRuntime(input))),
+        },
+        selfInvocation,
+        clientTerminals: {},
+      });
+      const threadId = ThreadId.make("thread-acp-always-allow");
+      const runtimePolicy = ProviderAdapter.ProviderAdapterV2RuntimePolicy.make({
+        runtimeMode: "approval-required",
+        interactionMode: "default",
+        cwd: process.cwd(),
+      });
+      const modelSelection = { instanceId, model: "default" } as const;
+      const runtime = yield* adapter.openSession({
+        threadId,
+        providerSessionId: ProviderSessionId.make("provider-session-acp-always-allow"),
+        modelSelection,
+        runtimePolicy,
+      });
+      const providerThread = yield* runtime.ensureThread({
+        threadId,
+        modelSelection,
+        runtimePolicy,
+      });
+      const turnFiber = yield* runtime
+        .startTurn(
+          makeTurnInput({
+            threadId,
+            providerThread,
+            instanceId,
+            runtimePolicy,
+            now: yield* DateTime.now,
+          }),
+        )
+        .pipe(Effect.forkScoped);
+      if (requestPermission === undefined) {
+        return yield* Effect.die("ACP runtime must register a permission handler");
+      }
+
+      const permissionFiber = yield* requestPermission(
+        {
+          sessionId: "mock-session-1",
+          toolCall: { toolCallId: "always-allow-tool", title: "Run tests", kind: "execute" },
+          options,
+        },
+        { requestId: "always-allow-request", method: "session/request_permission" },
+      ).pipe(Effect.forkScoped);
+      const pending = Option.getOrThrow(
+        yield* runtime.events.pipe(
+          Stream.filter(
+            (event) =>
+              event.type === "runtime_request.updated" && event.runtimeRequest.status === "pending",
+          ),
+          Stream.runHead,
+        ),
+      );
+      if (
+        pending.type !== "runtime_request.updated" ||
+        pending.runtimeRequest.providerTurnId === null
+      ) {
+        return yield* Effect.die("Expected an ACP approval request");
+      }
+      const responseFiber = yield* runtime
+        .respondToRuntimeRequest({
+          requestId: pending.runtimeRequest.id,
+          decision: "acceptForSession",
+        })
+        .pipe(Effect.forkScoped);
+      const { outcome } = yield* Fiber.join(permissionFiber);
+      if (runtimeInput?.onOutgoingResponse === undefined) {
+        return yield* Effect.die("ACP runtime must expose native response acknowledgements");
+      }
+      yield* runtimeInput.onOutgoingResponse("always-allow-request");
+      yield* Fiber.join(responseFiber);
+
+      yield* runtime.interruptTurn({
+        providerThread,
+        providerTurnId: pending.runtimeRequest.providerTurnId,
+      });
+      yield* Fiber.join(turnFiber);
+      assert.deepEqual(outcome, { outcome: "selected", optionId });
+    }).pipe(Effect.provide(layerTest), Effect.scoped),
+  );
+
   it.effect("replaces the ACP session and clears conversation state on rollback", () =>
     Effect.gen(function* () {
       const childProcessSpawner = yield* ChildProcessSpawner.ChildProcessSpawner;
diff --git a/packages/provider-acp/src/server/adapter.ts b/packages/provider-acp/src/server/adapter.ts
index b7c77c4049591..d74fdb2ec4f3a 100644
--- a/packages/provider-acp/src/server/adapter.ts
+++ b/packages/provider-acp/src/server/adapter.ts
@@ -1129,13 +1129,13 @@ function selectPermissionOptionId(
   request: EffectAcpSchema.RequestPermissionRequest,
   decision: Exclude<ProviderApprovalDecision, "cancel">,
 ): string | undefined {
-  const kind =
-    decision === "acceptForSession"
-      ? "allow_always"
-      : decision === "accept"
-        ? "allow_once"
-        : "reject_once";
-  return request.options.find((option) => option.kind === kind)?.optionId.trim() || undefined;
+  const optionIdOfKind = (kind: EffectAcpSchema.PermissionOption["kind"]) =>
+    request.options.find((option) => option.kind === kind)?.optionId.trim() || undefined;
+  if (decision === "acceptForSession") {
+    // Agents may offer only allow_once, and answering "cancelled" would stop the turn the user approved.
+    return optionIdOfKind("allow_always") ?? optionIdOfKind("allow_once");
+  }
+  return optionIdOfKind(decision === "accept" ? "allow_once" : "reject_once");
 }
 
 // Prefer allow-once; allow-always can persist beyond the session.