feat: make worktree branch prefix configurable

apps/server/src/git/Layers/GitManager.test.ts

@@ -463,7 +463,7 @@ function resolvePullRequest(manager: GitManagerShape, input: { cwd: string; refe
 
 function preparePullRequestThread(
   manager: GitManagerShape,
-  input: { cwd: string; reference: string; mode: "local" | "worktree" },
+  input: { cwd: string; reference: string; mode: "local" | "worktree"; branchPrefix?: string },
 ) {
   return manager.preparePullRequestThread(input);
 }
@@ -1789,6 +1789,59 @@ it.layer(GitManagerTestLayer)("GitManager", (it) => {
       }),
   );
 
+  it.effect("uses a custom prefix for cross-repo PR worktree branches", () =>
+    Effect.gen(function* () {
+      const repoDir = yield* makeTempDir("t3code-git-manager-");
+      yield* initRepo(repoDir);
+      const originDir = yield* createBareRemote();
+      const forkDir = yield* createBareRemote();
+      yield* runGit(repoDir, ["remote", "add", "origin", originDir]);
+      yield* runGit(repoDir, ["push", "-u", "origin", "main"]);
+      yield* runGit(repoDir, ["remote", "add", "fork-seed", forkDir]);
+      yield* runGit(repoDir, ["checkout", "-b", "fork-main-source"]);
+      fs.writeFileSync(path.join(repoDir, "fork-custom-prefix.txt"), "fork custom prefix\n");
+      yield* runGit(repoDir, ["add", "fork-custom-prefix.txt"]);
+      yield* runGit(repoDir, ["commit", "-m", "Fork custom prefix branch"]);
+      yield* runGit(repoDir, ["push", "-u", "fork-seed", "fork-main-source:main"]);
+      yield* runGit(repoDir, ["checkout", "main"]);
+
+      const { manager } = yield* makeManager({
+        ghScenario: {
+          pullRequest: {
+            number: 93,
+            title: "Fork main custom prefix PR",
+            url: "https://github.com/pingdotgg/codething-mvp/pull/93",
+            baseRefName: "main",
+            headRefName: "main",
+            state: "open",
+            isCrossRepository: true,
+            headRepositoryNameWithOwner: "octocat/codething-mvp",
+            headRepositoryOwnerLogin: "octocat",
+          },
+          repositoryCloneUrls: {
+            "octocat/codething-mvp": {
+              url: forkDir,
+              sshUrl: forkDir,
+            },
+          },
+        },
+      });
+
+      const result = yield* preparePullRequestThread(manager, {
+        cwd: repoDir,
+        reference: "93",
+        mode: "worktree",
+        branchPrefix: "custom/team",
+      });
+
+      expect(result.branch).toBe("custom/team/pr-93/main");
+      expect(result.worktreePath).not.toBeNull();
+      expect(
+        (yield* runGit(result.worktreePath as string, ["branch", "--show-current"])).stdout.trim(),
+      ).toBe("custom/team/pr-93/main");
+    }),
+  );
+
   it.effect(
     "does not overwrite an existing local main branch when preparing a fork PR worktree",
     () =>

apps/server/src/git/Layers/GitManager.ts

@@ -4,7 +4,7 @@ import { realpathSync } from "node:fs";
 import { Effect, FileSystem, Layer, Path } from "effect";
 import {
   resolveAutoFeatureBranchName,
-  sanitizeBranchFragment,
+  resolvePullRequestWorktreeLocalBranchName,
   sanitizeFeatureBranchName,
 } from "@t3tools/shared/git";
 
@@ -81,18 +81,6 @@ function resolveHeadRepositoryNameWithOwner(
   return `${ownerLogin}/${repositoryName}`;
 }
 
-function resolvePullRequestWorktreeLocalBranchName(
-  pullRequest: ResolvedPullRequest & PullRequestHeadRemoteInfo,
-): string {
-  if (!pullRequest.isCrossRepository) {
-    return pullRequest.headBranch;
-  }
-
-  const sanitizedHeadBranch = sanitizeBranchFragment(pullRequest.headBranch).trim();
-  const suffix = sanitizedHeadBranch.length > 0 ? sanitizedHeadBranch : "head";
-  return `t3code/pr-${pullRequest.number}/${suffix}`;
-}
-
 function parseGitHubRepositoryNameWithOwnerFromRemoteUrl(url: string | null): string | null {
   const trimmed = url?.trim() ?? "";
   if (trimmed.length === 0) {
@@ -880,8 +868,14 @@ export const makeGitManager = Effect.gen(function* () {
         ...pullRequest,
         ...toPullRequestHeadRemoteInfo(pullRequestSummary),
       } as const;
-      const localPullRequestBranch =
-        resolvePullRequestWorktreeLocalBranchName(pullRequestWithRemoteInfo);
+      const localPullRequestBranch = resolvePullRequestWorktreeLocalBranchName({
+        number: pullRequestWithRemoteInfo.number,
+        headBranch: pullRequestWithRemoteInfo.headBranch,
+        ...(pullRequestWithRemoteInfo.isCrossRepository !== undefined
+          ? { isCrossRepository: pullRequestWithRemoteInfo.isCrossRepository }
+          : {}),
+        ...(input.branchPrefix ? { branchPrefix: input.branchPrefix } : {}),
+      });
 
       const findLocalHeadBranch = (cwd: string) =>
         gitCore.listBranches({ cwd }).pipe(

apps/server/src/orchestration/Layers/ProviderCommandReactor.test.ts

@@ -175,14 +175,13 @@ describe("ProviderCommandReactor", () => {
             : "renamed-branch",
       }),
     );
-    const generateBranchName = vi.fn(() =>
+    const generateBranchName = vi.fn((() =>
       Effect.fail(
         new TextGenerationError({
           operation: "generateBranchName",
           detail: "disabled in test harness",
         }),
-      ),
-    );
+      )) as TextGenerationShape["generateBranchName"]);
 
     const unsupported = () => Effect.die(new Error("Unsupported provider call in test")) as never;
     const service: ProviderServiceShape = {
@@ -1299,4 +1298,56 @@ describe("ProviderCommandReactor", () => {
     expect(thread?.session?.threadId).toBe("thread-1");
     expect(thread?.session?.activeTurnId).toBeNull();
   });
+
+  it("preserves a custom temporary worktree prefix when renaming the first-turn branch", async () => {
+    const harness = await createHarness();
+    const now = new Date().toISOString();
+
+    harness.generateBranchName.mockImplementation(() =>
+      Effect.succeed({
+        branch: "feat/refine-toolbar",
+      }),
+    );
+
+    await Effect.runPromise(
+      harness.engine.dispatch({
+        type: "thread.meta.update",
+        commandId: CommandId.makeUnsafe("cmd-thread-meta-custom-prefix"),
+        threadId: ThreadId.makeUnsafe("thread-1"),
+        branch: "custom/team/1a2b3c4d",
+        worktreePath: "/tmp/provider-project-worktree",
+      }),
+    );
+
+    await Effect.runPromise(
+      harness.engine.dispatch({
+        type: "thread.turn.start",
+        commandId: CommandId.makeUnsafe("cmd-turn-start-custom-prefix"),
+        threadId: ThreadId.makeUnsafe("thread-1"),
+        message: {
+          messageId: asMessageId("user-message-custom-prefix"),
+          role: "user",
+          text: "refine the branch toolbar interactions",
+          attachments: [],
+        },
+        interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+        runtimeMode: "approval-required",
+        createdAt: now,
+      }),
+    );
+
+    await waitFor(() => harness.renameBranch.mock.calls.length === 1);
+    expect(harness.renameBranch.mock.calls[0]?.[0]).toMatchObject({
+      oldBranch: "custom/team/1a2b3c4d",
+      newBranch: "custom/team/feat/refine-toolbar",
+    });
+
+    await waitFor(async () => {
+      const readModel = await Effect.runPromise(harness.engine.getReadModel());
+      const thread = readModel.threads.find(
+        (entry) => entry.id === ThreadId.makeUnsafe("thread-1"),
+      );
+      return thread?.branch === "custom/team/feat/refine-toolbar";
+    });
+  });
 });

apps/server/src/orchestration/Layers/ProviderCommandReactor.ts

@@ -15,6 +15,11 @@ import {
 } from "@t3tools/contracts";
 import { Cache, Cause, Duration, Effect, Layer, Option, Schema, Stream } from "effect";
 import { makeDrainableWorker } from "@t3tools/shared/DrainableWorker";
+import {
+  buildGeneratedWorktreeBranchName,
+  extractTemporaryWorktreeBranchPrefix,
+  isTemporaryWorktreeBranch,
+} from "@t3tools/shared/git";
 
 import { resolveThreadWorkspaceCwd } from "../../checkpointing/Utils.ts";
 import { GitCore } from "../../git/Services/GitCore.ts";
@@ -73,8 +78,6 @@ const serverCommandId = (tag: string): CommandId =>
 const HANDLED_TURN_START_KEY_MAX = 10_000;
 const HANDLED_TURN_START_KEY_TTL = Duration.minutes(30);
 const DEFAULT_RUNTIME_MODE: RuntimeMode = "full-access";
-const WORKTREE_BRANCH_PREFIX = "t3code";
-const TEMP_WORKTREE_BRANCH_PATTERN = new RegExp(`^${WORKTREE_BRANCH_PREFIX}\\/[0-9a-f]{8}$`);
 
 const sameModelOptions = (
   left: ProviderModelOptions | undefined,
@@ -111,34 +114,6 @@ function stalePendingRequestDetail(
 ): string {
   return `Stale pending ${requestKind} request: ${requestId}. Provider callback state does not survive app restarts or recovered sessions. Restart the turn to continue.`;
 }
-
-function isTemporaryWorktreeBranch(branch: string): boolean {
-  return TEMP_WORKTREE_BRANCH_PATTERN.test(branch.trim().toLowerCase());
-}
-
-function buildGeneratedWorktreeBranchName(raw: string): string {
-  const normalized = raw
-    .trim()
-    .toLowerCase()
-    .replace(/^refs\/heads\//, "")
-    .replace(/['"`]/g, "");
-
-  const withoutPrefix = normalized.startsWith(`${WORKTREE_BRANCH_PREFIX}/`)
-    ? normalized.slice(`${WORKTREE_BRANCH_PREFIX}/`.length)
-    : normalized;
-
-  const branchFragment = withoutPrefix
-    .replace(/[^a-z0-9/_-]+/g, "-")
-    .replace(/\/+/g, "/")
-    .replace(/-+/g, "-")
-    .replace(/^[./_-]+|[./_-]+$/g, "")
-    .slice(0, 64)
-    .replace(/[./_-]+$/g, "");
-
-  const safeFragment = branchFragment.length > 0 ? branchFragment : "update";
-  return `${WORKTREE_BRANCH_PREFIX}/${safeFragment}`;
-}
-
 const make = Effect.gen(function* () {
   const orchestrationEngine = yield* OrchestrationEngineService;
   const providerService = yield* ProviderService;
@@ -461,7 +436,10 @@ const make = Effect.gen(function* () {
         Effect.flatMap((generated) => {
           if (!generated) return Effect.void;
 
-          const targetBranch = buildGeneratedWorktreeBranchName(generated.branch);
+          const targetBranch = buildGeneratedWorktreeBranchName(
+            generated.branch,
+            extractTemporaryWorktreeBranchPrefix(oldBranch),
+          );
           if (targetBranch === oldBranch) return Effect.void;
 
           return Effect.flatMap(

apps/web/src/appSettings.ts

@@ -1,5 +1,6 @@
 import { useCallback } from "react";
 import { Option, Schema } from "effect";
+import { DEFAULT_WORKTREE_BRANCH_PREFIX, normalizeWorktreeBranchPrefix } from "@t3tools/shared/git";
 import { TrimmedNonEmptyString, type ProviderKind } from "@t3tools/contracts";
 import { getDefaultModel, getModelOptions, normalizeModelSlug } from "@t3tools/shared/model";
 import { useLocalStorage } from "./hooks/useLocalStorage";
@@ -41,6 +42,9 @@ export const AppSettingsSchema = Schema.Struct({
   customCodexModels: Schema.Array(Schema.String).pipe(withDefaults(() => [])),
   customClaudeModels: Schema.Array(Schema.String).pipe(withDefaults(() => [])),
   textGenerationModel: Schema.optional(TrimmedNonEmptyString),
+  worktreeBranchPrefix: Schema.String.check(Schema.isMaxLength(256)).pipe(
+    withDefaults(() => DEFAULT_WORKTREE_BRANCH_PREFIX),
+  ),
 });
 export type AppSettings = typeof AppSettingsSchema.Type;
 export interface AppModelOption {
@@ -85,6 +89,7 @@ function normalizeAppSettings(settings: AppSettings): AppSettings {
     ...settings,
     customCodexModels: normalizeCustomModelSlugs(settings.customCodexModels, "codex"),
     customClaudeModels: normalizeCustomModelSlugs(settings.customClaudeModels, "claudeAgent"),
+    worktreeBranchPrefix: normalizeWorktreeBranchPrefix(settings.worktreeBranchPrefix),
   };
 }
 export function getAppModelOptions(

apps/web/src/components/ChatView.logic.ts

@@ -1,4 +1,5 @@
 import { ProjectId, type ProviderKind, type ThreadId } from "@t3tools/contracts";
+import { normalizeWorktreeBranchPrefix } from "@t3tools/shared/git";
 import { type ChatMessage, type Thread } from "../types";
 import { randomUUID } from "~/lib/utils";
 import { getAppModelOptions } from "../appSettings";
@@ -11,7 +12,6 @@ import {
 } from "../lib/terminalContext";
 
 export const LAST_INVOKED_SCRIPT_BY_PROJECT_KEY = "t3code:last-invoked-script-by-project";
-const WORKTREE_BRANCH_PREFIX = "t3code";
 
 export const LastInvokedScriptByProjectSchema = Schema.Record(ProjectId, Schema.String);
 
@@ -99,10 +99,10 @@ export function readFileAsDataUrl(file: File): Promise<string> {
   });
 }
 
-export function buildTemporaryWorktreeBranchName(): string {
+export function buildTemporaryWorktreeBranchName(prefix: string): string {
   // Keep the 8-hex suffix shape for backend temporary-branch detection.
   const token = randomUUID().slice(0, 8).toLowerCase();
-  return `${WORKTREE_BRANCH_PREFIX}/${token}`;
+  return `${normalizeWorktreeBranchPrefix(prefix)}/${token}`;
 }
 
 export function cloneComposerImageForRetry(

apps/web/src/components/ChatView.tsx

@@ -2543,7 +2543,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
       // On first message: lock in branch + create worktree if needed.
       if (baseBranchForWorktree) {
         beginSendPhase("preparing-worktree");
-        const newBranch = buildTemporaryWorktreeBranchName();
+        const newBranch = buildTemporaryWorktreeBranchName(settings.worktreeBranchPrefix);
         const result = await createWorktreeMutation.mutateAsync({
           cwd: activeProject.cwd,
           branch: baseBranchForWorktree,
@@ -4123,6 +4123,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
               key={pullRequestDialogState.key}
               open
               cwd={activeProject?.cwd ?? null}
+              branchPrefix={settings.worktreeBranchPrefix}
               initialReference={pullRequestDialogState.initialReference}
               onOpenChange={(open) => {
                 if (!open) {

apps/web/src/components/PullRequestThreadDialog.tsx

@@ -25,6 +25,7 @@ import { Spinner } from "./ui/spinner";
 interface PullRequestThreadDialogProps {
   open: boolean;
   cwd: string | null;
+  branchPrefix: string;
   initialReference: string | null;
   onOpenChange: (open: boolean) => void;
   onPrepared: (input: { branch: string; worktreePath: string | null }) => Promise<void> | void;
@@ -33,6 +34,7 @@ interface PullRequestThreadDialogProps {
 export function PullRequestThreadDialog({
   open,
   cwd,
+  branchPrefix,
   initialReference,
   onOpenChange,
   onPrepared,
@@ -130,6 +132,7 @@ export function PullRequestThreadDialog({
         const result = await preparePullRequestThreadMutation.mutateAsync({
           reference: parsedReference,
           mode,
+          branchPrefix,
         });
         await onPrepared({
           branch: result.branch,
@@ -141,6 +144,7 @@ export function PullRequestThreadDialog({
       }
     },
     [
+      branchPrefix,
       cwd,
       onOpenChange,
       onPrepared,

apps/web/src/lib/gitReactQuery.ts

@@ -201,13 +201,22 @@ export function gitPreparePullRequestThreadMutationOptions(input: {
   queryClient: QueryClient;
 }) {
   return mutationOptions({
-    mutationFn: async ({ reference, mode }: { reference: string; mode: "local" | "worktree" }) => {
+    mutationFn: async ({
+      reference,
+      mode,
+      branchPrefix,
+    }: {
+      reference: string;
+      mode: "local" | "worktree";
+      branchPrefix?: string;
+    }) => {
       const api = ensureNativeApi();
       if (!input.cwd) throw new Error("Pull request thread preparation is unavailable.");
       return api.git.preparePullRequestThread({
         cwd: input.cwd,
         reference,
         mode,
+        ...(branchPrefix ? { branchPrefix } : {}),
       });
     },
     mutationKey: gitMutationKeys.preparePullRequestThread(input.cwd),