diff --git a/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts b/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts
index 4aeca83b7762..3e167bee6ded 100644
--- a/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts
+++ b/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts
@@ -1,6 +1,7 @@
 import * as NodeServices from "@effect/platform-node/NodeServices";
 import {
   GrokSettings,
+  ProjectId,
   ProviderInstanceId,
   ProviderSessionId,
   type RuntimeMode,
@@ -12,6 +13,7 @@ import * as EffectAcpErrors from "effect-acp/errors";
 import { xAiRateLimitedErrorCode } from "../../provider/acp/XAiAcpExtension.ts";
 import { assert, describe, it } from "@effect/vitest";
 import * as Crypto from "effect/Crypto";
+import * as DateTime from "effect/DateTime";
 import * as Effect from "effect/Effect";
 import * as FileSystem from "effect/FileSystem";
 import * as Layer from "effect/Layer";
@@ -21,8 +23,16 @@ import { ChildProcessSpawner } from "effect/unstable/process";
 import type * as EffectAcpSchema from "effect-acp/compat";
 
 import { ServerConfig } from "../../config.ts";
+import { ProjectionProjectRepository } from "../../persistence/Services/ProjectionProjects.ts";
+import { buildInitialGrokProviderSnapshot } from "../../provider/Layers/GrokProvider.ts";
+import type { ProviderInstance } from "../../provider/ProviderDriver.ts";
+import { ProviderInstanceRegistry } from "../../provider/Services/ProviderInstanceRegistry.ts";
 import { layer as idAllocatorLayer, IdAllocatorV2 } from "../IdAllocator.ts";
 import { ProviderAdapterV2RuntimePolicy } from "../ProviderAdapter.ts";
+import {
+  layerFromProjectRepository as runtimePolicyLayerFromProjectRepository,
+  RuntimePolicyV2,
+} from "../RuntimePolicy.ts";
 import { acpPermissionDisposition } from "../../provider/acp/AcpClientPolicy.ts";
 import {
   AcpProviderCapabilitiesV2,
@@ -341,7 +351,6 @@ describe("Grok launch permission mode", () => {
 
   for (const [runtimeMode, args] of [
     ["approval-required", ["--permission-mode", "default", "agent", "stdio"]],
-    ["auto-accept-edits", ["--permission-mode", "default", "agent", "stdio"]],
     ["auto", ["--permission-mode", "auto", "agent", "stdio"]],
     ["full-access", ["agent", "--always-approve", "stdio"]],
   ] as const) {
@@ -352,6 +361,68 @@ describe("Grok launch permission mode", () => {
     );
   }
 
+  it.effect("launches a thread stored as Auto-accept edits asking", () =>
+    Effect.gen(function* () {
+      // The policy the orchestrator resolves from Grok's own provider snapshot.
+      const snapshot = yield* buildInitialGrokProviderSnapshot(LAUNCH_TEST_GROK_SETTINGS);
+      const instanceId = ProviderInstanceId.make("grok-launch-test");
+      const now = yield* DateTime.now;
+      const threadId = ThreadId.make("grok-launch-test");
+      const modelSelection = { instanceId, model: "grok-build" } as const;
+      const resolved = yield* Effect.gen(function* () {
+        const runtimePolicy = yield* RuntimePolicyV2;
+        return yield* runtimePolicy.resolve({
+          thread: {
+            createdBy: "user",
+            creationSource: "web",
+            id: threadId,
+            projectId: ProjectId.make("grok-launch-test"),
+            title: "Grok launch test",
+            providerInstanceId: instanceId,
+            modelSelection,
+            runtimeMode: "auto-accept-edits",
+            interactionMode: "default",
+            branch: null,
+            worktreePath: process.cwd(),
+            activeProviderThreadId: null,
+            lineage: { parentThreadId: null, relationshipToParent: null, rootThreadId: threadId },
+            forkedFrom: null,
+            createdAt: now,
+            updatedAt: now,
+            archivedAt: null,
+            settledOverride: null,
+            settledAt: null,
+            lastVisitedAt: null,
+            deletedAt: null,
+          },
+          modelSelection,
+        });
+      }).pipe(
+        Effect.provide(
+          runtimePolicyLayerFromProjectRepository.pipe(
+            Layer.provide(
+              Layer.mock(ProjectionProjectRepository)({
+                getById: () => Effect.die("the thread has a worktree"),
+              }),
+            ),
+            Layer.provide(
+              Layer.mock(ProviderInstanceRegistry)({
+                getInstance: () =>
+                  Effect.succeed({
+                    snapshot: { getSnapshot: Effect.succeed(snapshot) },
+                  } as ProviderInstance),
+              }),
+            ),
+          ),
+        ),
+      );
+      assert.equal(resolved.runtimeMode, "approval-required");
+      assert.deepEqual(yield* launchArgs(resolved), [
+        ["--permission-mode", "default", "agent", "stdio"],
+      ]);
+    }),
+  );
+
   it.effect("launches asking when an explicit approval or sandbox policy governs the thread", () =>
     Effect.gen(function* () {
       const asking = [["--permission-mode", "default", "agent", "stdio"]];
diff --git a/apps/server/src/orchestration-v2/DelegatedCompletionDelivery.test.ts b/apps/server/src/orchestration-v2/DelegatedCompletionDelivery.test.ts
index 567fea60f7c4..8da8378a8b6e 100644
--- a/apps/server/src/orchestration-v2/DelegatedCompletionDelivery.test.ts
+++ b/apps/server/src/orchestration-v2/DelegatedCompletionDelivery.test.ts
@@ -79,7 +79,8 @@ const providerInstance = {
   },
   displayName: "Codex test",
   enabled: true,
-  snapshot: {} as ProviderInstance["snapshot"],
+  // No supportedRuntimeModes: every runtime mode runs as stored.
+  snapshot: { getSnapshot: Effect.succeed({}) } as unknown as ProviderInstance["snapshot"],
   orchestrationAdapter,
   textGeneration: {} as ProviderInstance["textGeneration"],
 } satisfies ProviderInstance;
diff --git a/apps/server/src/orchestration-v2/RuntimePolicy.test.ts b/apps/server/src/orchestration-v2/RuntimePolicy.test.ts
index f08d5525cb7f..03fd762fd723 100644
--- a/apps/server/src/orchestration-v2/RuntimePolicy.test.ts
+++ b/apps/server/src/orchestration-v2/RuntimePolicy.test.ts
@@ -4,14 +4,19 @@ import {
   type OrchestrationV2AppThread,
   ProjectId,
   ProviderInstanceId,
+  type RuntimeMode,
+  type ServerProvider,
   ThreadId,
 } from "@t3tools/contracts";
 import * as DateTime from "effect/DateTime";
 import * as Effect from "effect/Effect";
 import * as Layer from "effect/Layer";
 import * as Option from "effect/Option";
+import * as Stream from "effect/Stream";
 
 import * as ProjectionProjects from "../persistence/Services/ProjectionProjects.ts";
+import type { ProviderInstance } from "../provider/ProviderDriver.ts";
+import { ProviderInstanceRegistry } from "../provider/Services/ProviderInstanceRegistry.ts";
 import { layerFromProjectRepository, RuntimePolicyV2 } from "./RuntimePolicy.ts";
 
 const projectId = ProjectId.make("project:runtime-policy");
@@ -24,6 +29,7 @@ const modelSelection = {
 function makeThread(input: {
   readonly now: DateTime.Utc;
   readonly worktreePath: string | null;
+  readonly runtimeMode?: RuntimeMode;
 }): OrchestrationV2AppThread {
   const threadId = ThreadId.make("thread:runtime-policy");
   return {
@@ -34,7 +40,7 @@ function makeThread(input: {
     title: "Runtime policy",
     providerInstanceId,
     modelSelection,
-    runtimeMode: "full-access",
+    runtimeMode: input.runtimeMode ?? "full-access",
     interactionMode: "default",
     branch: null,
     worktreePath: input.worktreePath,
@@ -55,7 +61,31 @@ function makeThread(input: {
   };
 }
 
+// Grok's instance offers no Auto-accept edits; the Codex instance advertises no
+// restriction.
+const grokInstanceId = ProviderInstanceId.make("grok");
+const supportedRuntimeModesByInstance = new Map<ProviderInstanceId, ReadonlyArray<RuntimeMode>>([
+  [grokInstanceId, ["approval-required", "auto", "full-access"]],
+]);
+const providerInstanceFor = (instanceId: ProviderInstanceId) =>
+  ({
+    snapshot: {
+      getSnapshot: Effect.succeed({
+        supportedRuntimeModes: supportedRuntimeModesByInstance.get(instanceId),
+      } as ServerProvider),
+    },
+  }) as ProviderInstance;
+
 const TestLayer = layerFromProjectRepository.pipe(
+  Layer.provide(
+    Layer.succeed(ProviderInstanceRegistry, {
+      getInstance: (instanceId) => Effect.succeed(providerInstanceFor(instanceId)),
+      listInstances: Effect.succeed([]),
+      listUnavailable: Effect.succeed([]),
+      streamChanges: Stream.empty,
+      subscribeChanges: Effect.never,
+    }),
+  ),
   Layer.provide(
     Layer.mock(ProjectionProjects.ProjectionProjectRepository)({
       getById: () =>
@@ -101,4 +131,24 @@ it.layer(TestLayer)("RuntimePolicyV2", (it) => {
       assert.equal(resolved.cwd, "/project-worktree");
     }),
   );
+
+  it.effect("runs a mode the provider does not offer in Supervised", () =>
+    Effect.gen(function* () {
+      const policy = yield* RuntimePolicyV2;
+      const now = yield* DateTime.now;
+      const modeFor = (instanceId: ProviderInstanceId, runtimeMode: RuntimeMode) =>
+        policy
+          .resolve({
+            thread: makeThread({ now, worktreePath: null, runtimeMode }),
+            modelSelection: { instanceId, model: "test-model" },
+          })
+          .pipe(Effect.map((resolved) => resolved.runtimeMode));
+
+      assert.equal(yield* modeFor(grokInstanceId, "auto-accept-edits"), "approval-required");
+      assert.equal(yield* modeFor(grokInstanceId, "auto"), "auto");
+      assert.equal(yield* modeFor(grokInstanceId, "full-access"), "full-access");
+      // A provider that advertises no restriction runs every mode as stored.
+      assert.equal(yield* modeFor(providerInstanceId, "auto-accept-edits"), "auto-accept-edits");
+    }),
+  );
 });
diff --git a/apps/server/src/orchestration-v2/RuntimePolicy.ts b/apps/server/src/orchestration-v2/RuntimePolicy.ts
index be44653e7af7..4c78c53cfd55 100644
--- a/apps/server/src/orchestration-v2/RuntimePolicy.ts
+++ b/apps/server/src/orchestration-v2/RuntimePolicy.ts
@@ -3,6 +3,7 @@ import {
   OrchestrationV2AppThread,
   ProjectId,
   ProviderInstanceId,
+  type RuntimeMode,
 } from "@t3tools/contracts";
 import * as Context from "effect/Context";
 import * as Effect from "effect/Effect";
@@ -11,6 +12,7 @@ import * as Option from "effect/Option";
 import * as Schema from "effect/Schema";
 
 import * as ProjectionProjects from "../persistence/Services/ProjectionProjects.ts";
+import { ProviderInstanceRegistry } from "../provider/Services/ProviderInstanceRegistry.ts";
 import {
   ProviderAdapterV2RuntimePolicy,
   type ProviderAdapterV2RuntimePolicy as ProviderAdapterV2RuntimePolicyType,
@@ -69,16 +71,38 @@ export const layer: Layer.Layer<RuntimePolicyV2> = Layer.succeed(RuntimePolicyV2
     }),
 });
 
+/**
+ * The mode a provider runs a thread in. A mode the provider does not offer
+ * (a thread set before it stopped offering it, or a stale client) runs in
+ * Supervised rather than having T3 imitate it.
+ */
+function providerRuntimeMode(
+  runtimeMode: RuntimeMode,
+  supportedRuntimeModes: ReadonlyArray<RuntimeMode> | undefined,
+): RuntimeMode {
+  return supportedRuntimeModes === undefined ||
+    supportedRuntimeModes.length === 0 ||
+    supportedRuntimeModes.includes(runtimeMode)
+    ? runtimeMode
+    : "approval-required";
+}
+
 export const layerFromProjectRepository: Layer.Layer<
   RuntimePolicyV2,
   never,
-  ProjectionProjects.ProjectionProjectRepository
+  ProjectionProjects.ProjectionProjectRepository | ProviderInstanceRegistry
 > = Layer.effect(
   RuntimePolicyV2,
   Effect.gen(function* () {
     const projects = yield* ProjectionProjects.ProjectionProjectRepository;
+    const providerInstances = yield* ProviderInstanceRegistry;
     return RuntimePolicyV2.of({
       resolve: Effect.fn("RuntimePolicyV2.resolve")(function* (input) {
+        const instance = yield* providerInstances.getInstance(input.modelSelection.instanceId);
+        const supportedRuntimeModes =
+          instance === undefined
+            ? undefined
+            : (yield* instance.snapshot.getSnapshot).supportedRuntimeModes;
         const cwd =
           input.thread.worktreePath ??
           (yield* projects.getById({ projectId: input.thread.projectId }).pipe(
@@ -105,7 +129,7 @@ export const layerFromProjectRepository: Layer.Layer<
             ),
           ));
         return ProviderAdapterV2RuntimePolicy.make({
-          runtimeMode: input.thread.runtimeMode,
+          runtimeMode: providerRuntimeMode(input.thread.runtimeMode, supportedRuntimeModes),
           interactionMode: input.thread.interactionMode,
           cwd,
         });
diff --git a/apps/server/src/orchestration-v2/runtimeLayer.test.ts b/apps/server/src/orchestration-v2/runtimeLayer.test.ts
index 19f156d723f3..266bed6d9fdd 100644
--- a/apps/server/src/orchestration-v2/runtimeLayer.test.ts
+++ b/apps/server/src/orchestration-v2/runtimeLayer.test.ts
@@ -128,7 +128,8 @@ const providerInstance = {
   },
   displayName: "Codex test",
   enabled: true,
-  snapshot: {} as ProviderInstance["snapshot"],
+  // No supportedRuntimeModes: every runtime mode runs as stored.
+  snapshot: { getSnapshot: Effect.succeed({}) } as unknown as ProviderInstance["snapshot"],
   orchestrationAdapter,
   textGeneration: {} as ProviderInstance["textGeneration"],
 } satisfies ProviderInstance;
diff --git a/apps/server/src/provider/Layers/GrokProvider.ts b/apps/server/src/provider/Layers/GrokProvider.ts
index 7096d7d48f5f..9da0c08cff4a 100644
--- a/apps/server/src/provider/Layers/GrokProvider.ts
+++ b/apps/server/src/provider/Layers/GrokProvider.ts
@@ -37,6 +37,7 @@ import {
 } from "../providerMaintenance.ts";
 import {
   GROK_DEFAULT_MODEL_SLUG,
+  GROK_SUPPORTED_RUNTIME_MODES,
   isValidGrokReasoningEffortToken,
   makeGrokAcpRuntime,
   resolveGrokAcpBaseModelId,
@@ -48,6 +49,7 @@ const GROK_PRESENTATION = {
   displayName: "Grok",
   supportsConversationRollback: false,
   showInteractionModeToggle: false,
+  supportedRuntimeModes: GROK_SUPPORTED_RUNTIME_MODES,
 } as const;
 const EMPTY_CAPABILITIES: ModelCapabilities = createModelCapabilities({
   optionDescriptors: [],
diff --git a/apps/server/src/provider/acp/AcpClientPolicy.test.ts b/apps/server/src/provider/acp/AcpClientPolicy.test.ts
index 463b8fcf1edc..9dabeda83ebf 100644
--- a/apps/server/src/provider/acp/AcpClientPolicy.test.ts
+++ b/apps/server/src/provider/acp/AcpClientPolicy.test.ts
@@ -92,7 +92,7 @@ describe("acpPermissionDisposition", () => {
   });
 
   it("auto-accept-edits approves file changes without locations and asks for the rest", () => {
-    // Grok's session/request_permission carries no locations.
+    // ACP permission requests need not carry locations.
     const autoAcceptEdits: AcpRuntimePolicy = { runtimeMode: "auto-accept-edits", cwd };
     for (const kind of ["edit", "delete", "move"] as const) {
       assert.equal(acpPermissionDisposition(autoAcceptEdits, permissionRequest(kind)), "allow");
diff --git a/apps/server/src/provider/acp/AcpClientPolicy.ts b/apps/server/src/provider/acp/AcpClientPolicy.ts
index ce3e18c07443..1a7c3f5bb231 100644
--- a/apps/server/src/provider/acp/AcpClientPolicy.ts
+++ b/apps/server/src/provider/acp/AcpClientPolicy.ts
@@ -209,7 +209,7 @@ function acpOperationDisposition(
     case undefined:
       if (runtimePolicy.runtimeMode === "approval-required") return "deny";
       // Auto-accept edits approves file changes wherever the agent makes them
-      // (Grok's prompts carry no locations to confine); other actions still ask.
+      // (ACP prompts need not carry locations to confine); other actions still ask.
       if (
         runtimePolicy.runtimeMode === "auto-accept-edits" &&
         runtimePolicy.approvalPolicy === undefined &&
diff --git a/apps/server/src/provider/acp/GrokAcpSupport.test.ts b/apps/server/src/provider/acp/GrokAcpSupport.test.ts
index d766abad06d1..d15b12fbc2da 100644
--- a/apps/server/src/provider/acp/GrokAcpSupport.test.ts
+++ b/apps/server/src/provider/acp/GrokAcpSupport.test.ts
@@ -61,14 +61,14 @@ describe("grokAcpSpawnArgs", () => {
     expect(grokAcpSpawnArgs("full-access")).toEqual(["agent", "--always-approve", "stdio"]);
   });
 
-  it("launches Auto-accept edits asking and Auto on Grok's classifier", () => {
+  it("launches Auto on Grok's classifier and a mode Grok does not offer asking", () => {
+    expect(grokAcpSpawnArgs("auto")).toEqual(["--permission-mode", "auto", "agent", "stdio"]);
     expect(grokAcpSpawnArgs("auto-accept-edits")).toEqual([
       "--permission-mode",
       "default",
       "agent",
       "stdio",
     ]);
-    expect(grokAcpSpawnArgs("auto")).toEqual(["--permission-mode", "auto", "agent", "stdio"]);
   });
 });
 
diff --git a/apps/server/src/provider/acp/GrokAcpSupport.ts b/apps/server/src/provider/acp/GrokAcpSupport.ts
index ce3611a9097f..7b50e566599b 100644
--- a/apps/server/src/provider/acp/GrokAcpSupport.ts
+++ b/apps/server/src/provider/acp/GrokAcpSupport.ts
@@ -32,24 +32,32 @@ interface GrokAcpRuntimeInput extends Omit<
   readonly runtimeMode?: RuntimeMode;
 }
 
+/**
+ * The runtime modes `grok agent` can launch in: ask, its auto classifier, and
+ * always-approve. It has no Auto-accept edits: `acceptEdits` only exists as a
+ * settings-file `permissions.defaultMode`, and `grok agent` treats it as ask.
+ */
+export const GROK_SUPPORTED_RUNTIME_MODES = [
+  "approval-required",
+  "auto",
+  "full-access",
+] as const satisfies ReadonlyArray<RuntimeMode>;
+
 /**
  * Launch argv for a runtime mode. `--permission-mode` on the argv beats the
  * user's Grok config, so Supervised cannot inherit a configured always-approve.
- * `grok agent` only wires always-approve and auto at launch; `acceptEdits`
- * would behave exactly like `default`, so Auto-accept edits launches asking
- * and T3's ACP client policy approves the edit prompts.
+ * A mode Grok does not offer launches asking.
  */
 export function grokAcpSpawnArgs(runtimeMode?: RuntimeMode): ReadonlyArray<string> {
   switch (runtimeMode) {
-    case "approval-required":
-    case "auto-accept-edits":
-      return ["--permission-mode", "default", "agent", "stdio"];
+    case undefined:
+      return ["agent", "stdio"];
     case "auto":
       return ["--permission-mode", "auto", "agent", "stdio"];
     case "full-access":
       return ["agent", "--always-approve", "stdio"];
     default:
-      return ["agent", "stdio"];
+      return ["--permission-mode", "default", "agent", "stdio"];
   }
 }