diff --git a/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts b/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts
index 6604edbf82a8c..7a922d79c7317 100644
--- a/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts
+++ b/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts
@@ -3,6 +3,7 @@ import { expect, it, vi } from "vite-plus/test";
 import { it as effectIt } from "@effect/vitest";
 import {
   CheckpointScopeId,
+  GitCommandError,
   MessageId,
   NodeId,
   ProviderSessionId,
@@ -33,6 +34,8 @@ import * as Schema from "effect/Schema";
 import * as ServerConfig from "../config.ts";
 import { withWorkspaceLease } from "../workspace/workspaceLease.ts";
 import * as GitWorkflow from "../git/GitWorkflowService.ts";
+import * as GitVcsDriver from "../vcs/GitVcsDriver.ts";
+import { layerRealGit } from "./ProviderTurnStartService.testkit.ts";
 import * as ProjectService from "../project/ProjectService.ts";
 import * as ProviderAuthService from "../provider/ProviderAuthService.ts";
 import * as ServerSettings from "../serverSettings.ts";
@@ -121,6 +124,7 @@ function startWithMissingWorktree(
   const startRootRun = vi.fn(() => Effect.void);
   const pruneWorktrees = vi.fn(() => Effect.void);
   const createWorktree = vi.fn(() => Effect.succeed({} as never));
+  const listLocalBranchNames = vi.fn(() => Effect.succeed(["feature/restore"]));
   const layer = ProviderTurnStart.layer.pipe(
     Layer.provide(
       Layer.mergeAll(
@@ -142,7 +146,11 @@ function startWithMissingWorktree(
                 ),
         } as never),
         layerWorktreeLocation(),
-        Layer.mock(GitWorkflow.GitWorkflowService)({ pruneWorktrees, createWorktree }),
+        Layer.mock(GitWorkflow.GitWorkflowService)({
+          pruneWorktrees,
+          createWorktree,
+          listLocalBranchNames,
+        }),
         Layer.mock(ProjectService.ProjectService)({
           getById: () =>
             Effect.succeedSome({ workspaceRoot: "/tmp/provider-turn-start-project" } as never),
@@ -257,6 +265,8 @@ function makeLocalCommandHarness(input: {
   readonly text: string;
   readonly worktreePath?: string;
   readonly worktreesDir?: string;
+  readonly workspaceRoot?: string;
+  readonly gitWorkflow?: GitWorkflow.GitWorkflowService["Service"];
   readonly fileSystem?: FileSystem.FileSystem;
   readonly previousNativeSession?: boolean;
   readonly previousMessages?: ReadonlyArray<string>;
@@ -664,7 +674,9 @@ function makeLocalCommandHarness(input: {
     ({ thread }: Parameters<RuntimePolicy.RuntimePolicyV2Shape["resolve"]>[0]) =>
       Effect.succeed({ cwd: thread.worktreePath ?? "/tmp/native-account-command" } as never),
   );
-  const createWorktree = vi.fn(() => Effect.succeed({} as never));
+  const createWorktree = vi.fn<GitWorkflow.GitWorkflowService["Service"]["createWorktree"]>(() =>
+    Effect.succeed({} as never),
+  );
   const getThreadRecords = vi.fn<ProjectionStore.ProjectionStoreV2Shape["getThreadRecords"]>(() =>
     Effect.succeed(projection),
   );
@@ -690,13 +702,18 @@ function makeLocalCommandHarness(input: {
         input.fileSystem === undefined
           ? FileSystem.layerNoop({ exists: () => Effect.succeed(true) })
           : Layer.succeed(FileSystem.FileSystem, input.fileSystem),
-        Layer.mock(GitWorkflow.GitWorkflowService)({
-          pruneWorktrees: () => Effect.void,
-          createWorktree,
-        }),
+        input.gitWorkflow === undefined
+          ? Layer.mock(GitWorkflow.GitWorkflowService)({
+              pruneWorktrees: () => Effect.void,
+              listLocalBranchNames: () => Effect.succeed(["feature/restore"]),
+              createWorktree,
+            })
+          : Layer.succeed(GitWorkflow.GitWorkflowService, input.gitWorkflow),
         Layer.mock(ProjectService.ProjectService)({
           getById: () =>
-            Effect.succeedSome({ workspaceRoot: "/tmp/native-account-project" } as never),
+            Effect.succeedSome({
+              workspaceRoot: input.workspaceRoot ?? "/tmp/native-account-project",
+            } as never),
         }),
         Layer.mock(ProjectionStore.ProjectionStoreV2)({
           getThreadRecords,
@@ -770,6 +787,167 @@ function makeLocalCommandHarness(input: {
   };
 }
 
+effectIt.effect(
+  "recovers the thread branch tip, falls back to the current project branch, and rejects detached HEAD",
+  () =>
+    Effect.gen(function* () {
+      const fileSystem = yield* FileSystem.FileSystem;
+      const path = yield* Path.Path;
+      const gitWorkflow = yield* GitWorkflow.GitWorkflowService;
+      const driver = yield* GitVcsDriver.GitVcsDriver;
+      const root = yield* fileSystem.makeTempDirectoryScoped({ prefix: "t3-recreate-repo-" });
+      const workspaceRoot = path.join(root, "project");
+      const worktreesDir = path.join(root, "worktrees");
+      const worktreePath = path.join(worktreesDir, "project", "restore");
+      yield* fileSystem.makeDirectory(workspaceRoot);
+      const git = (cwd: string, args: ReadonlyArray<string>) =>
+        driver
+          .execute({ operation: "test.worktreeRecovery", cwd, args })
+          .pipe(Effect.map((result) => result.stdout.trim()));
+      yield* git(workspaceRoot, ["init", "-b", "main"]);
+      yield* git(workspaceRoot, ["config", "user.name", "Test"]);
+      yield* git(workspaceRoot, ["config", "user.email", "test@example.com"]);
+      yield* git(workspaceRoot, ["commit", "--allow-empty", "-m", "base"]);
+      yield* git(workspaceRoot, ["worktree", "add", "-b", "feature/restore", worktreePath]);
+      yield* fileSystem.writeFileString(path.join(worktreePath, "thread.txt"), "thread work");
+      yield* git(worktreePath, ["add", "."]);
+      yield* git(worktreePath, ["commit", "-m", "thread tip"]);
+      const threadTip = yield* git(worktreePath, ["rev-parse", "HEAD"]);
+      yield* git(workspaceRoot, ["switch", "-c", "project-current"]);
+      yield* fileSystem.writeFileString(
+        path.join(workspaceRoot, "project.txt"),
+        "new project code",
+      );
+      yield* git(workspaceRoot, ["add", "."]);
+      yield* git(workspaceRoot, ["commit", "-m", "project tip"]);
+      const projectTip = yield* git(workspaceRoot, ["rev-parse", "HEAD"]);
+      expect(projectTip).not.toBe(threadTip);
+      // Tags must neither hide the thread branch nor select a different recovery tip.
+      yield* git(workspaceRoot, ["tag", "feature/restore", projectTip]);
+      yield* git(workspaceRoot, ["tag", "project-current", threadTip]);
+
+      // Reuse the workflow across turns so recovery cannot select a cached project branch.
+      for (const scenario of ["retained", "deleted", "detached"] as const) {
+        yield* fileSystem.remove(worktreePath, { recursive: true });
+        if (scenario !== "retained") {
+          yield* git(workspaceRoot, ["worktree", "prune"]);
+          yield* git(workspaceRoot, ["branch", "-D", "feature/restore"]);
+        }
+        if (scenario === "detached") {
+          yield* git(workspaceRoot, ["switch", "--detach"]);
+          expect(yield* git(workspaceRoot, ["branch", "--show-current"])).toBe("");
+        }
+        const harness = makeLocalCommandHarness({
+          text: "Continue",
+          workspaceRoot,
+          worktreePath,
+          worktreesDir,
+          fileSystem,
+          gitWorkflow,
+          failReadsAfterRunning: true,
+        });
+        const open = harness.open.getMockImplementation()!;
+        harness.open.mockImplementation(() =>
+          Effect.gen(function* () {
+            expect(yield* git(worktreePath, ["branch", "--show-current"])).toBe("feature/restore");
+            expect(yield* git(worktreePath, ["rev-parse", "HEAD"])).toBe(
+              scenario === "retained" ? threadTip : projectTip,
+            );
+            expect(
+              yield* fileSystem.readFileString(
+                path.join(worktreePath, scenario === "retained" ? "thread.txt" : "project.txt"),
+              ),
+            ).toBe(scenario === "retained" ? "thread work" : "new project code");
+            return yield* open();
+          }).pipe(Effect.orDie),
+        );
+
+        yield* harness.start;
+
+        if (scenario === "detached") {
+          expect(harness.open).not.toHaveBeenCalled();
+          expect(harness.startRootRun).not.toHaveBeenCalled();
+          expect(harness.projection().runs.at(-1)?.status).toBe("failed");
+          expect(harness.projection().turnItems).toMatchObject([
+            { type: "error", failure: { message: expect.stringContaining("no current branch") } },
+          ]);
+          expect(yield* fileSystem.exists(worktreePath)).toBe(false);
+          expect(yield* git(workspaceRoot, ["branch", "--list", "feature/restore"])).toBe("");
+        } else {
+          expect(harness.open).toHaveBeenCalledOnce();
+          expect(harness.startRootRun).toHaveBeenCalledWith(
+            expect.objectContaining({
+              runtimePolicy: expect.objectContaining({ cwd: worktreePath }),
+            }),
+          );
+          expect(harness.projection().runs.at(-1)?.status).toBe("running");
+        }
+      }
+    }).pipe(Effect.scoped, Effect.provide(layerRealGit)),
+);
+
+effectIt.effect(
+  "preserves recreation interrupts and retries, then fails the final attempt before provider start",
+  () =>
+    Effect.gen(function* () {
+      const fileSystem = yield* FileSystem.FileSystem;
+      const path = yield* Path.Path;
+      const worktreesDir = yield* fileSystem.makeTempDirectoryScoped({
+        prefix: "t3-recreate-failure-",
+      });
+      const worktreePath = path.join(worktreesDir, "project", "restore");
+      const harness = makeLocalCommandHarness({
+        text: "Continue",
+        worktreesDir,
+        worktreePath,
+        fileSystem,
+        failReadsAfterRunning: true,
+      });
+      harness.createWorktree.mockImplementationOnce(() => Effect.interrupt);
+      harness.createWorktree.mockImplementation(() =>
+        Effect.fail(
+          new GitCommandError({
+            operation: "worktree-add",
+            command: "git worktree add",
+            cwd: "/tmp/native-account-project",
+            detail: "fatal: private git diagnostic",
+          }),
+        ),
+      );
+
+      const interrupted = yield* Effect.exit(harness.start);
+      expect(interrupted._tag).toBe("Failure");
+      if (interrupted._tag === "Failure")
+        expect(Cause.hasInterruptsOnly(interrupted.cause)).toBe(true);
+      expect(harness.events).toEqual([]);
+      expect(harness.projection().runs.at(-1)?.status).toBe("starting");
+
+      const retry = yield* Effect.result(harness.startWithRetry);
+      expect(retry).toMatchObject({ _tag: "Failure", failure: { _tag: "ProviderTurnStartError" } });
+      expect(harness.events).toEqual([]);
+      expect(harness.projection().runs.at(-1)?.status).toBe("starting");
+
+      yield* harness.start;
+      expect(harness.createWorktree).toHaveBeenCalledTimes(3);
+      expect(harness.writeIfRunCurrent).toHaveBeenCalledOnce();
+      expect(harness.open).not.toHaveBeenCalled();
+      expect(harness.startRootRun).not.toHaveBeenCalled();
+      const projection = harness.projection();
+      expect(projection.runs.at(-1)).toMatchObject({ status: "failed", startedAt: null });
+      expect(projection.attempts[0]).toMatchObject({ status: "failed", startedAt: null });
+      expect(projection.nodes[0]).toMatchObject({ status: "failed", startedAt: null });
+      expect(projection.turnItems).toMatchObject([
+        {
+          type: "error",
+          failure: {
+            message: `Could not recreate the worktree for branch 'feature/restore' at ${worktreePath}.`,
+          },
+        },
+      ]);
+      expect(JSON.stringify(harness.events)).not.toContain("private git diagnostic");
+    }).pipe(Effect.scoped, Effect.provide(NodeServices.layer)),
+);
+
 effectIt.effect("recovers an abandoned failed turn before continuing its native conversation", () =>
   Effect.gen(function* () {
     const harness = makeLocalCommandHarness({
diff --git a/apps/server/src/orchestration-v2/ProviderTurnStartService.testkit.ts b/apps/server/src/orchestration-v2/ProviderTurnStartService.testkit.ts
index 6e517ef73a66b..5b614b1e2aa6c 100644
--- a/apps/server/src/orchestration-v2/ProviderTurnStartService.testkit.ts
+++ b/apps/server/src/orchestration-v2/ProviderTurnStartService.testkit.ts
@@ -1,3 +1,18 @@
+import { SourceControlProviderError, SourceControlProviderKind } from "@t3tools/contracts";
+import * as NodeServices from "@effect/platform-node/NodeServices";
+import * as ServerConfig from "../config.ts";
+import * as GitManager from "../git/GitManager.ts";
+import * as GitVcsDriver from "../vcs/GitVcsDriver.ts";
+import * as VcsDriverRegistry from "../vcs/VcsDriverRegistry.ts";
+import * as VcsProjectConfig from "../vcs/VcsProjectConfig.ts";
+import * as VcsProcess from "../vcs/VcsProcess.ts";
+import * as ServerSettings from "../serverSettings.ts";
+import * as ProjectSetupScriptRunner from "../project/ProjectSetupScriptRunner.ts";
+import * as ProviderRegistry from "../provider/ProviderRegistry.ts";
+import * as SourceControlProviderRegistry from "../sourceControl/SourceControlProviderRegistry.ts";
+import * as TextGeneration from "../textGeneration/TextGeneration.ts";
+import * as ProjectionStore from "./ProjectionStore.ts";
+import * as ProjectStore from "./ProjectStore.ts";
 import * as Effect from "effect/Effect";
 import * as Layer from "effect/Layer";
 
@@ -13,3 +28,35 @@ export const layer = Layer.merge(
     getById: () => Effect.succeedNone,
   }),
 );
+
+// Keep repository detection, branch selection and worktree creation on the real Git path.
+export const layerRealGit = GitWorkflow.layer.pipe(
+  Layer.provide(GitManager.layer),
+  Layer.provide(
+    Layer.mergeAll(
+      Layer.mock(SourceControlProviderRegistry.SourceControlProviderRegistry)({
+        resolveLink: () => undefined,
+        resolve: ({ cwd }) =>
+          Effect.fail(
+            new SourceControlProviderError({
+              provider: SourceControlProviderKind.make("unknown"),
+              operation: "resolve",
+              cwd,
+              detail: "No source control provider in tests",
+            }),
+          ),
+      }),
+      Layer.mock(TextGeneration.TextGeneration)({}),
+      Layer.mock(ProviderRegistry.ProviderRegistry)({}),
+      Layer.mock(ProjectSetupScriptRunner.ProjectSetupScriptRunner)({}),
+      Layer.mock(ProjectionStore.ProjectionStoreV2)({}),
+      Layer.mock(ProjectStore.ProjectStoreV2)({}),
+      ServerSettings.layerTest(),
+    ),
+  ),
+  Layer.provide(VcsDriverRegistry.layer.pipe(Layer.provide(VcsProjectConfig.layer))),
+  Layer.provideMerge(GitVcsDriver.layer),
+  Layer.provideMerge(VcsProcess.layer),
+  Layer.provideMerge(ServerConfig.layerTest(process.cwd(), { prefix: "t3-recreate-" })),
+  Layer.provideMerge(NodeServices.layer),
+);
diff --git a/apps/server/src/orchestration-v2/ProviderTurnStartService.ts b/apps/server/src/orchestration-v2/ProviderTurnStartService.ts
index 97fdb7c85ca71..9d9ae2e646cd5 100644
--- a/apps/server/src/orchestration-v2/ProviderTurnStartService.ts
+++ b/apps/server/src/orchestration-v2/ProviderTurnStartService.ts
@@ -15,7 +15,6 @@ import {
   ThreadId,
 } from "@t3tools/contracts";
 import * as Context from "effect/Context";
-import * as Cause from "effect/Cause";
 import * as DateTime from "effect/DateTime";
 import * as Effect from "effect/Effect";
 import * as FileSystem from "effect/FileSystem";
@@ -68,6 +67,28 @@ export class ProviderTurnStartError extends Schema.TaggedError<ProviderTurnStart
   },
 ) {}
 
+class WorktreeRecreateError extends Schema.TaggedError<WorktreeRecreateError>()(
+  "WorktreeRecreateError",
+  {
+    worktreePath: Schema.String,
+    branch: Schema.String,
+    cause: Schema.Defect(),
+  },
+) {
+  override get message(): string {
+    return `Could not recreate the worktree for branch '${this.branch}' at ${this.worktreePath}.`;
+  }
+}
+
+class WorktreeRecreateNoBaseError extends Schema.TaggedError<WorktreeRecreateNoBaseError>()(
+  "WorktreeRecreateNoBaseError",
+  { worktreePath: Schema.String, branch: Schema.String },
+) {
+  override get message(): string {
+    return `Could not recreate branch '${this.branch}' at ${this.worktreePath}: the project workspace has no current branch to start it from (detached HEAD?).`;
+  }
+}
+
 const isProviderTurnStartError = Schema.is(ProviderTurnStartError);
 
 /**
@@ -131,6 +152,35 @@ export const layer: Layer.Layer<
     const runtimePolicy = yield* RuntimePolicy.RuntimePolicyV2;
     const isManagedWorktreePath = yield* makeIsManagedWorktreePath;
 
+    const recreateMissingWorktree = Effect.fn("ProviderTurnStartService.recreateMissingWorktree")(
+      function* (input: {
+        readonly cwd: string;
+        readonly worktreePath: string;
+        readonly branch: string;
+      }) {
+        const { cwd, worktreePath, branch } = input;
+        yield* gitWorkflow.pruneWorktrees({ cwd });
+        const localBranchNames = yield* gitWorkflow.listLocalBranchNames(cwd);
+        if (localBranchNames.includes(branch)) {
+          yield* gitWorkflow.createWorktree({ cwd, refName: branch, path: worktreePath });
+          return;
+        }
+        // Recovery can follow an external checkout, before the status cache expires.
+        yield* gitWorkflow.invalidateLocalStatus(cwd);
+        const { refName: baseRef } = yield* gitWorkflow.localStatus({ cwd });
+        if (baseRef === null) {
+          return yield* new WorktreeRecreateNoBaseError({ worktreePath, branch });
+        }
+        yield* gitWorkflow.createWorktree({
+          cwd,
+          refName: `refs/heads/${baseRef}`,
+          newRefName: branch,
+          baseRefName: `refs/heads/${baseRef}`,
+          path: worktreePath,
+        });
+      },
+    );
+
     // Build draining callbacks outside startup scope so they cannot retain full thread history.
     const makeRunControls = (input: {
       readonly threadId: ThreadId;
@@ -399,6 +449,39 @@ export const layer: Layer.Layer<
           });
         },
       );
+      const settleStartFailure = Effect.fn("ProviderTurnStartService.settleStartFailure")(
+        function* (failed: {
+          readonly signal: string;
+          readonly title: string;
+          readonly error: Error;
+          readonly message?: string;
+        }) {
+          const nestedCause = "cause" in failed.error ? failed.error.cause : undefined;
+          yield* settleRunBeforeStart({
+            signal: failed.signal,
+            status: "failed",
+            now: yield* DateTime.now,
+            providerInstanceId: run.providerInstanceId,
+            itemProviderThreadId: providerThread.id,
+            item: {
+              type: "error",
+              title: failed.title,
+              failure: makeProviderFailure({
+                cause: failed.error,
+                message:
+                  failed.message ??
+                  knownProviderFailureMessage(failed.error) ??
+                  (nestedCause instanceof Error
+                    ? nestedCause.message
+                    : typeof nestedCause === "string"
+                      ? nestedCause
+                      : failed.error.message),
+                class: "provider_error",
+              }),
+            },
+          });
+        },
+      );
       if (message.attachments.length === 0 && message.text.trimStart().startsWith("/")) {
         const isEmptyCompaction =
           message.text.trim().toLowerCase() === "/compact" && !projection.hasConversation;
@@ -500,24 +583,29 @@ export const layer: Layer.Layer<
               worktreePath,
               branch,
             });
-            yield* gitWorkflow.pruneWorktrees({ cwd: project.workspaceRoot }).pipe(
-              Effect.andThen(
-                gitWorkflow.createWorktree({
-                  cwd: project.workspaceRoot,
-                  refName: branch,
-                  path: worktreePath,
-                }),
-              ),
-              Effect.catchCauseIf(
-                (cause) => !Cause.hasInterruptsOnly(cause),
-                (cause) =>
-                  Effect.logWarning("provider turn start failed to recreate worktree", {
-                    threadId: projection.thread.id,
-                    worktreePath,
-                    cause: Cause.pretty(cause),
-                  }),
+            const recreateResult = yield* Effect.result(
+              recreateMissingWorktree({
+                cwd: project.workspaceRoot,
+                worktreePath,
+                branch,
+              }).pipe(
+                Effect.mapError((cause) =>
+                  cause._tag === "WorktreeRecreateNoBaseError"
+                    ? cause
+                    : new WorktreeRecreateError({ worktreePath, branch, cause }),
+                ),
               ),
             );
+            if (recreateResult._tag === "Failure") {
+              if (input.willRetry === true) return yield* recreateResult.failure;
+              yield* settleStartFailure({
+                signal: "worktree-recreate-failure",
+                title: "Couldn't recreate thread workspace",
+                error: recreateResult.failure,
+                message: recreateResult.failure.message,
+              });
+              return;
+            }
           }
         }
       }
@@ -553,37 +641,6 @@ export const layer: Layer.Layer<
       const existingSessionProjection = projection.providerSessions.find(
         (candidate) => candidate.id === providerSessionId,
       );
-      const settleStartFailure = Effect.fn("ProviderTurnStartService.settleStartFailure")(
-        function* (failed: {
-          readonly signal: string;
-          readonly title: string;
-          readonly error: Error;
-        }) {
-          const nestedCause = "cause" in failed.error ? failed.error.cause : undefined;
-          yield* settleRunBeforeStart({
-            signal: failed.signal,
-            status: "failed",
-            now: yield* DateTime.now,
-            providerInstanceId: run.providerInstanceId,
-            itemProviderThreadId: providerThread.id,
-            item: {
-              type: "error",
-              title: failed.title,
-              failure: makeProviderFailure({
-                cause: failed.error,
-                message:
-                  knownProviderFailureMessage(failed.error) ??
-                  (nestedCause instanceof Error
-                    ? nestedCause.message
-                    : typeof nestedCause === "string"
-                      ? nestedCause
-                      : failed.error.message),
-                class: "provider_error",
-              }),
-            },
-          });
-        },
-      );
       const failedRuns = new Map(
         projection.runs
           .filter(
diff --git a/apps/server/src/vcs/GitVcsDriverCore.ts b/apps/server/src/vcs/GitVcsDriverCore.ts
index 8c15b808d61e2..e151e22782b9f 100644
--- a/apps/server/src/vcs/GitVcsDriverCore.ts
+++ b/apps/server/src/vcs/GitVcsDriverCore.ts
@@ -4385,7 +4385,7 @@ export const makeGitVcsDriverCore = Effect.fn("makeGitVcsDriverCore")(function*
       "branch",
       "--list",
       "--no-column",
-      "--format=%(refname:short)",
+      "--format=%(refname:lstrip=2)",
     ]).pipe(
       Effect.map((stdout) => {
         const branchNames: Array<string> = [];