diff --git a/.project-docs/30-worklog/tasks/20260826-ml01-project-identity-4d8a7c21.md b/.project-docs/30-worklog/tasks/20260826-ml01-project-identity-4d8a7c21.md
new file mode 100644
index 0000000..8b4ec6e
--- /dev/null
+++ b/.project-docs/30-worklog/tasks/20260826-ml01-project-identity-4d8a7c21.md
@@ -0,0 +1,118 @@
+# Task: Implement ML-01 project identity contract
+
+## Identity
+
+- Task ID: 20260826-ml01-project-identity-4d8a7c21
+- Mode: Feature
+- Branch: codex/20260826-ml01-project-identity-4d8a7c21-ml01-project-identity
+- Worktree: D:\Datas\OthersProjects\makelore-ml01-project-identity-4d8a7c21
+- Base commit: 7e54b8fbda1899b73334d7c3e732ce8e73460ed8
+- Owner: ml01-project-identity
+- Status: Ready for integration
+
+## Scope
+
+- Implement ML-01 durable project identity core from the accepted MakeLore Data
+  Service P0 specification, sections 5.1 and 8.1/8.3-8.5, on the exact base
+  `7e54b8fbda1899b73334d7c3e732ce8e73460ed8`.
+- Own only the ticket paths: shared project contracts; project config,
+  project service, migration, coding-project Host routes and composition
+  identity callback wiring; Pi release-proof create fixtures; and identity
+  focused/direct create-project tests required by the new request contract.
+- Deliver optional canonical `projectId` persistence, required create/bind
+  creation identity, one-time legacy resolution, immutable ordinary saves,
+  confirmed independent-copy identity rotation, one centralized active-real-
+  project-with-identity helper, and atomic preview/resource invalidation.
+
+## Intent And Constraints
+
+- Work in the isolated ticket worktree and branch owned by this task. Do not
+  modify the occupied root `main` worktree or absorb changes from other tasks.
+- Preserve local `CodingProjectSummary.id`, normalized-path reuse/index
+  behavior, Pi local project/session identifiers, and the `opencode-projects`
+  electron-store compatibility name. None may become the durable cloud ID.
+- Do not add Data Service cloud/Host calls, Firebase compatibility, published
+  runtime support, generic operation multiplexing, or a filesystem-copy engine.
+- New creation must require an explicit `{kind: "create"|"bind"}` identity;
+  Main generates `crypto.randomUUID()` for create and validates canonical
+  lowercase hyphenated UUIDs for bind. Legacy config opening/migration must
+  remain identity-free until a dedicated identity operation.
+- Ordinary config saves preserve an existing identity and reject changes or
+  clear attempts; only the identity-resolution or confirmed independent-copy
+  operation may write it. Preview invalidation runs before the atomic metadata
+  write and callback failure must leave config unchanged.
+- The centralized active-real-project helper must validate indexed active
+  project, resolved/stat'ed directory, `.niancode/project.json`, durable ID,
+  and trusted-context path equality without accepting model/tool owner or ID.
+
+## Planning Gate
+
+- Result: Passed on 2026-08-26 after Concurrent Task Gate isolation.
+- Task identity, exact base, branch, worktree, and owner match the local
+  `task_context.py status --json` record.
+- Loaded MakeLore AGENTS, required project-memory entry documents, accepted
+  architecture/domain/decision/evidence/commitment material, the cross-repo
+  Data Service spec sections 5.1 and 8.1/8.3-8.5, and the ML-01 ticket plan.
+- Active peer review found the parent client coordinator task with the same
+  overall program but no semantic conflict; other planning records were either
+  placeholder/unknown or unrelated. The root integration record is completed;
+  root remains out of scope per the user handoff.
+- Project positioning is still a template placeholder and therefore stale
+  context, not a source of product behavior; the accepted spec and contract
+  are the authoritative task inputs.
+
+## Implementation Plan
+
+1. Inspect the exact-base project identity/config/migration/service/route,
+   composition, Pi release-proof, and affected test seams; map all direct
+   create callers before editing.
+2. Add contract/config normalization and migration-preserving optional identity,
+   then enforce required create identity and atomic creation semantics.
+3. Add immutable save and one-time identity-resolution/independent-copy
+   operations, centralized active-real-project helper, route wiring, callback
+   invalidation, and release-proof/test fixtures.
+4. Run focused identity tests plus typecheck and relevant lint/build checks;
+   inspect the diff for ownership boundaries and task-specific regressions.
+5. Update this record with actual outcome/verification, run doc drift and
+   complete the task context, then commit one implementation commit.
+
+## Outcome
+
+- Implemented ML-01 in the isolated client worktree. V2 project metadata now
+  optionally persists a canonical lowercase hyphenated UUID without silently
+  backfilling legacy projects; Main-owned creation requires an explicit
+  create/bind choice and validates/generates the durable ID before any project
+  directory/config write. Ordinary saves preserve identity immutability.
+- Added one-time legacy resolution and confirmed independent-copy operations,
+  exact Host routes, callback-before-atomic-write sequencing, resource refresh
+  hooks, centralized active-real-project-with-identity validation, and the
+  affected Pi release-proof/direct create fixtures.
+- Preserved local summary/store IDs, migration omission, normalized-path
+  behavior, local Pi identifiers, and the existing project-store compatibility
+  name. No cloud/data-service calls or filesystem-copy engine were added.
+
+## Verification
+
+- `tsc --noEmit` passed with the bundled Node/TypeScript runtime.
+- Focused Vitest passed: `coding-project-identity.test.ts` (8 tests),
+  `coding-projects-migration.test.ts` (8 tests),
+  `coding-core-routes.test.ts` (28 tests), and
+  `coding-projects-schema-v2.test.ts` (4 tests); 48 tests total.
+- Focused ESLint passed for all modified implementation and test files.
+- `git diff --check` passed.
+- The initial dependency install attempted to add an approval note to
+  `pnpm-workspace.yaml`; it was removed immediately and is not part of this
+  task's diff.
+
+## Follow-ups
+
+- ML-02 must project the required identity choice into the Renderer create and
+  legacy/independent-copy UX. ML-03 must use
+  `requireActiveRealProjectWithIdentity()` for all Data Service callers.
+- Parent merger should integrate this commit after confirming the exact
+  post-ML-00 base and rerun the repository-wide client gates.
+
+## Promotion Candidates
+
+- None: this ticket implements the accepted identity contract without a new
+  project-memory decision or canonical-document change.
diff --git a/electron/api/coding-composition.ts b/electron/api/coding-composition.ts
index e6d4fd0..2aa3d52 100644
--- a/electron/api/coding-composition.ts
+++ b/electron/api/coding-composition.ts
@@ -178,6 +178,9 @@ export function createCodingComposition(
         .catch(() => []);
       for (const conversation of conversations) registry.forget(conversation.id);
     },
+    onProjectIdentityChanging: async (project) => {
+      await options.browser.close(project.path);
+    },
     onProjectDeactivated: async (project, reason) => {
       const conversations = await conversationStoreForProject(project.path).read()
         .then((file) => file.conversations)
diff --git a/electron/api/routes/coding-projects.ts b/electron/api/routes/coding-projects.ts
index b836ee9..7fe6d5a 100644
--- a/electron/api/routes/coding-projects.ts
+++ b/electron/api/routes/coding-projects.ts
@@ -1,5 +1,6 @@
 import type { IncomingMessage, ServerResponse } from 'node:http';
 import type { ProjectType } from '../../../shared/project-config';
+import type { ProjectIdentityChoice } from '../../../shared/coding-project-contracts';
 import type { CodingProjectConfigSnapshot } from '../../coding-projects/project-service';
 import type { CodingProject } from '../../coding-projects/project-store';
 import type { HostApiContext } from '../context';
@@ -65,10 +66,41 @@ export async function handleCodingProjectRoutes(
         parentPath?: string;
         projectName?: string;
         projectType?: ProjectType;
+        identity: ProjectIdentityChoice;
       }>(req);
       sendJson(res, 201, { snapshot: publicProjectSnapshot(await projects.createProject(body)) });
       return true;
     }
+    if (url.pathname === '/api/coding/projects/identity' && req.method === 'POST') {
+      const body = await parseJsonBody<{
+        localProjectId?: string;
+        identity: ProjectIdentityChoice;
+      }>(req);
+      sendJson(res, 200, {
+        snapshot: publicProjectSnapshot(
+          await projects.resolveProjectIdentity(
+            body.localProjectId ?? '',
+            body.identity,
+          ),
+        ),
+      });
+      return true;
+    }
+    if (url.pathname === '/api/coding/projects/identity/independent-copy' && req.method === 'POST') {
+      const body = await parseJsonBody<{
+        localProjectId?: string;
+        confirmed: unknown;
+      }>(req);
+      sendJson(res, 200, {
+        snapshot: publicProjectSnapshot(
+          await projects.makeProjectIndependentCopy(
+            body.localProjectId ?? '',
+            body.confirmed as true,
+          ),
+        ),
+      });
+      return true;
+    }
     if (url.pathname === '/api/coding/projects/remove' && req.method === 'POST') {
       const body = await parseJsonBody<{ projectId?: string }>(req);
       await projects.removeProject(body.projectId ?? '');
diff --git a/electron/api/routes/coding-route-errors.ts b/electron/api/routes/coding-route-errors.ts
index 0cf112a..5fe5618 100644
--- a/electron/api/routes/coding-route-errors.ts
+++ b/electron/api/routes/coding-route-errors.ts
@@ -5,6 +5,8 @@ import { sendJson } from '../route-utils';
 
 const FIXED_CODING_ERROR_MESSAGES: Readonly<Record<string, string>> = {
   CODING_ACTIVE_PROJECT_REQUIRED: '请先选择一个编程项目。',
+  CODING_ACTIVE_PROJECT_INVALID: '当前编程项目不可用，请重新打开。',
+  CODING_ACTIVE_PROJECT_PATH_MISMATCH: '当前编程项目路径已变化，请重新打开。',
   CODING_AGENT_NOT_FOUND: '当前伙伴不可用，请重新选择。',
   CODING_AGENT_ID_IMMUTABLE: '已有伙伴标识不能修改。',
   CODING_CONVERSATION_NOT_FOUND: '指定的对话不存在。',
@@ -19,6 +21,8 @@ const FIXED_CODING_ERROR_MESSAGES: Readonly<Record<string, string>> = {
   CODING_PROJECT_ALREADY_EXISTS: '该编程项目已经存在。',
   CODING_PROJECT_CONFIG_INVALID: '项目配置无效，请检查后重试。',
   CODING_PROJECT_IDENTITY_IMMUTABLE: '项目创建标识不能修改。',
+  CODING_PROJECT_IDENTITY_CONFIRMATION_REQUIRED: '设为独立副本需要明确确认。',
+  CODING_PROJECT_IDENTITY_REQUIRED: '请先为该编程项目选择项目 ID。',
   CODING_PROJECT_NOT_FOUND: '指定的编程项目不存在。',
   CODING_PROJECT_REQUEST_INVALID: '项目请求无效，请检查输入。',
   CODING_PROJECT_TYPE_IMMUTABLE: '项目类型创建后不能修改。',
diff --git a/electron/coding-projects/project-config.ts b/electron/coding-projects/project-config.ts
index 8386ce1..cfb03aa 100644
--- a/electron/coding-projects/project-config.ts
+++ b/electron/coding-projects/project-config.ts
@@ -9,6 +9,7 @@ import {
 import type {
   CodingProjectAgent,
   CodingProjectConfig,
+  ProjectIdentityChoice,
 } from '../../shared/coding-project-contracts';
 import type {
   ConversationModelState,
@@ -47,6 +48,24 @@ export interface CreateCodingProjectAgentInput {
   pinned?: boolean;
 }
 
+const CANONICAL_PROJECT_ID_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/u;
+
+export function isCanonicalCodingProjectId(value: unknown): value is string {
+  return typeof value === 'string' && CANONICAL_PROJECT_ID_PATTERN.test(value);
+}
+
+export function normalizeProjectIdentityChoice(value: unknown): ProjectIdentityChoice {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) {
+    throw new Error('Project identity choice is invalid');
+  }
+  const record = value as { kind?: unknown; projectId?: unknown };
+  if (record.kind === 'create') return { kind: 'create' };
+  if (record.kind === 'bind' && isCanonicalCodingProjectId(record.projectId)) {
+    return { kind: 'bind', projectId: record.projectId };
+  }
+  throw new Error('Project identity choice is invalid');
+}
+
 const AGENT_ID_PATTERN = /^[a-z0-9][a-z0-9-]{0,63}$/;
 const AVATAR_ID_PATTERN = /^avatar-(0[1-9]|1[0-6])$/;
 const THINKING_LEVELS = new Set<ConversationThinkingLevel>([
@@ -182,6 +201,9 @@ export function normalizeCodingProjectConfigV2(value: unknown): CodingProjectCon
   const record = value as Partial<CodingProjectConfigV2>;
   if (record.schemaVersion !== 2) throw new Error('Unsupported coding project config schema');
   if (!isProjectType(record.projectType)) throw new Error('Invalid project type');
+  if (record.projectId !== undefined && !isCanonicalCodingProjectId(record.projectId)) {
+    throw new Error('Project identity is invalid');
+  }
   if (typeof record.initialized !== 'boolean') throw new Error('Project initialized state is invalid');
   if (record.knowledgeDirectory !== 'knowledge') throw new Error('Project knowledge directory is invalid');
   if (!Array.isArray(record.agents)) throw new Error('Project Agents must be an array');
@@ -199,6 +221,7 @@ export function normalizeCodingProjectConfigV2(value: unknown): CodingProjectCon
   return {
     schemaVersion: 2,
     projectType: record.projectType,
+    ...(record.projectId !== undefined ? { projectId: record.projectId } : {}),
     initialized: record.initialized === true,
     agents,
     knowledgeDirectory: 'knowledge',
@@ -211,10 +234,15 @@ export function normalizeCodingProjectConfigV2(value: unknown): CodingProjectCon
 export function createCodingProjectConfigV2(
   now = new Date().toISOString(),
   projectType: ProjectType = 'custom',
+  projectId?: string,
 ): CodingProjectConfigV2 {
+  if (projectId !== undefined && !isCanonicalCodingProjectId(projectId)) {
+    throw new Error('Project identity is invalid');
+  }
   return {
     schemaVersion: 2,
     projectType,
+    ...(projectId !== undefined ? { projectId } : {}),
     initialized: false,
     agents: [],
     knowledgeDirectory: 'knowledge',
@@ -252,6 +280,7 @@ export async function createCodingProjectMetadata(
   projectPath: string,
   options: {
     projectType?: ProjectType;
+    projectId?: string;
     now?: string;
     writer?: JsonFileWriter;
   } = {},
@@ -262,7 +291,7 @@ export async function createCodingProjectMetadata(
   } catch (error) {
     if ((error as NodeJS.ErrnoException).code !== 'ENOENT') throw error;
   }
-  const config = createCodingProjectConfigV2(options.now, options.projectType);
+  const config = createCodingProjectConfigV2(options.now, options.projectType, options.projectId);
   await Promise.all([
     mkdir(path.join(projectPath, '.niancode'), { recursive: true }),
     mkdir(path.join(projectPath, 'knowledge'), { recursive: true }),
diff --git a/electron/coding-projects/project-service.ts b/electron/coding-projects/project-service.ts
index 6d45484..711faff 100644
--- a/electron/coding-projects/project-service.ts
+++ b/electron/coding-projects/project-service.ts
@@ -1,13 +1,17 @@
-import { mkdir, readdir, stat, writeFile } from 'node:fs/promises';
+import { randomUUID } from 'node:crypto';
+import { mkdir, readdir, realpath, stat, writeFile } from 'node:fs/promises';
 import path from 'node:path';
 import { isProjectType, type ProjectType } from '../../shared/project-config';
+import type { ProjectIdentityChoice } from '../../shared/coding-project-contracts';
 import {
   createCodingConversationStore,
   type CodingConversationV2,
 } from './conversation-store';
 import {
   acknowledgeLegacyConversationNotice,
+  isCanonicalCodingProjectId,
   normalizeCodingProjectConfigV2,
+  normalizeProjectIdentityChoice,
   readCodingProjectConfigV2,
   writeCodingProjectConfigV2,
   type CodingProjectConfigV2,
@@ -18,6 +22,7 @@ import {
 } from './migration';
 import {
   createLocalCodingProject,
+  normalizeCodingProjectPath,
   type CodingProject,
   type CodingProjectStore,
 } from './project-store';
@@ -50,6 +55,7 @@ export interface CreateCodingProjectRequest {
   parentPath?: string;
   projectName?: string;
   projectType?: ProjectType;
+  identity: ProjectIdentityChoice;
 }
 
 export interface CodingProjectConfigSnapshot {
@@ -59,7 +65,14 @@ export interface CodingProjectConfigSnapshot {
 }
 
 export interface CodingProjectServiceOptions {
+  createProjectId?: () => string;
+  now?: () => string;
   onResourcesChanged?(project: CodingProject): Promise<void> | void;
+  onProjectIdentityChanging?(
+    project: CodingProject,
+    previousProjectId: string | undefined,
+    nextProjectId: string,
+  ): Promise<void> | void;
   onProjectDeactivated?(
     project: CodingProject,
     reason: 'project_deactivated' | 'project_removed',
@@ -94,12 +107,40 @@ function assertStableConfig(previous: CodingProjectConfigV2, next: CodingProject
   if (next.createdAt !== previous.createdAt) {
     throw new CodingProjectServiceError(409, 'CODING_PROJECT_IDENTITY_IMMUTABLE', 'Project creation identity cannot be changed');
   }
+  if (next.projectId !== previous.projectId) {
+    throw new CodingProjectServiceError(409, 'CODING_PROJECT_IDENTITY_IMMUTABLE', 'Project creation identity cannot be changed');
+  }
   const nextIds = new Set(next.agents.map(({ id }) => id));
   if (previous.agents.some(({ id }) => !nextIds.has(id))) {
     throw new CodingProjectServiceError(409, 'CODING_AGENT_ID_IMMUTABLE', 'Existing Agent ids must be preserved');
   }
 }
 
+function resolveProjectIdentity(
+  identity: unknown,
+  createProjectId: () => string,
+): string {
+  let choice: ProjectIdentityChoice;
+  try {
+    choice = normalizeProjectIdentityChoice(identity);
+  } catch {
+    throw new CodingProjectServiceError(
+      400,
+      'CODING_PROJECT_REQUEST_INVALID',
+      'Project identity choice is invalid',
+    );
+  }
+  const projectId = choice.kind === 'create' ? createProjectId() : choice.projectId;
+  if (!isCanonicalCodingProjectId(projectId)) {
+    throw new CodingProjectServiceError(
+      400,
+      'CODING_PROJECT_REQUEST_INVALID',
+      'Project identity is invalid',
+    );
+  }
+  return projectId;
+}
+
 export class CodingProjectService {
   private readonly conversationStores = new Map<
     string,
@@ -107,6 +148,7 @@ export class CodingProjectService {
   >();
   private activeTransitionTail = Promise.resolve();
   private readonly migrationFlights = new Map<string, Promise<CodingProjectConfigV2>>();
+  private readonly identityTransitionTails = new Map<string, Promise<void>>();
 
   constructor(
     private readonly store: CodingProjectStore,
@@ -133,6 +175,67 @@ export class CodingProjectService {
     return project;
   }
 
+  async requireActiveRealProjectWithIdentity(trustedProjectPath?: string): Promise<{
+    project: CodingProject;
+    path: string;
+    projectId: string;
+  }> {
+    const project = await this.requireActiveProject();
+    let projectPath: string;
+    try {
+      projectPath = await realpath(path.resolve(project.path));
+    } catch {
+      throw new CodingProjectServiceError(
+        409,
+        'CODING_ACTIVE_PROJECT_INVALID',
+        'The active coding project directory is unavailable',
+      );
+    }
+    const entry = await stat(projectPath).catch(() => null);
+    if (!entry?.isDirectory()) {
+      throw new CodingProjectServiceError(
+        409,
+        'CODING_ACTIVE_PROJECT_INVALID',
+        'The active coding project directory is unavailable',
+      );
+    }
+    if (trustedProjectPath !== undefined) {
+      let trustedRealPath: string;
+      try {
+        trustedRealPath = await realpath(path.resolve(trustedProjectPath));
+      } catch {
+        throw new CodingProjectServiceError(
+          409,
+          'CODING_ACTIVE_PROJECT_PATH_MISMATCH',
+          'The trusted coding project path does not match the active project',
+        );
+      }
+      if (normalizeCodingProjectPath(trustedRealPath) !== normalizeCodingProjectPath(projectPath)) {
+        throw new CodingProjectServiceError(
+          409,
+          'CODING_ACTIVE_PROJECT_PATH_MISMATCH',
+          'The trusted coding project path does not match the active project',
+        );
+      }
+    }
+    const config = await this.readCurrentConfig(projectPath);
+    if (!config) {
+      throw new CodingProjectServiceError(
+        409,
+        'CODING_PROJECT_CONFIG_INVALID',
+        'Coding project configuration is unavailable',
+      );
+    }
+    if (!config.projectId) {
+      throw new CodingProjectServiceError(
+        409,
+        'CODING_PROJECT_IDENTITY_REQUIRED',
+        'A durable coding project identity is required',
+      );
+    }
+    return { project, path: projectPath, projectId: config.projectId };
+  }
+
   async getProject(projectId: string): Promise<CodingProject> {
     const id = projectId.trim();
     const project = (await this.store.listProjects()).find((candidate) => candidate.id === id);
@@ -159,6 +262,10 @@ export class CodingProjectService {
   }
 
   async createProject(input: CreateCodingProjectRequest): Promise<CodingProjectConfigSnapshot> {
+    const projectId = resolveProjectIdentity(
+      input.identity,
+      this.options.createProjectId ?? randomUUID,
+    );
     const selectedPath = input.projectPath?.trim();
     if (selectedPath && (input.parentPath?.trim() || input.projectName?.trim())) {
       throw new CodingProjectServiceError(400, 'CODING_PROJECT_REQUEST_INVALID', 'Project path input is ambiguous');
@@ -184,6 +291,7 @@ export class CodingProjectService {
       return await this.transitionActiveProject(async () => {
         const { project, config } = await createLocalCodingProject({
           projectPath,
+          projectId,
           ...(input.projectType ? { projectType: input.projectType } : {}),
         }, this.store);
         const snapshot = { project, config, knowledgeFiles: [] };
@@ -272,6 +380,97 @@ export class CodingProjectService {
     };
   }
 
+  async resolveProjectIdentity(
+    localProjectId: string,
+    identity: ProjectIdentityChoice,
+  ): Promise<CodingProjectConfigSnapshot> {
+    const project = await this.getProject(localProjectId);
+    return await this.serializeIdentityTransition(project.path, async () => {
+      const current = await this.getConfig(project.id);
+      if (current.config.projectId !== undefined) {
+        throw new CodingProjectServiceError(
+          409,
+          'CODING_PROJECT_IDENTITY_IMMUTABLE',
+          'Project creation identity cannot be changed',
+        );
+      }
+      const nextProjectId = resolveProjectIdentity(
+        identity,
+        this.options.createProjectId ?? randomUUID,
+      );
+      await this.options.onProjectIdentityChanging?.(
+        project,
+        undefined,
+        nextProjectId,
+      );
+      const next = {
+        ...current.config,
+        projectId: nextProjectId,
+        updatedAt: this.options.now?.() ?? new Date().toISOString(),
+      };
+      try {
+        await (this.options.writeConfig ?? writeCodingProjectConfigV2)(project.path, next);
+      } catch (error) {
+        storageFailure(error);
+      }
+      await this.options.onResourcesChanged?.(project);
+      return {
+        project: current.project,
+        config: next,
+        knowledgeFiles: await this.listKnowledgeFiles(current.project.path),
+      };
+    });
+  }
+
+  async makeProjectIndependentCopy(
+    localProjectId: string,
+    confirmed: true,
+  ): Promise<CodingProjectConfigSnapshot> {
+    if (confirmed !== true) {
+      throw new CodingProjectServiceError(
+        400,
+        'CODING_PROJECT_IDENTITY_CONFIRMATION_REQUIRED',
+        'Independent copy requires explicit confirmation',
+      );
+    }
+    const project = await this.getProject(localProjectId);
+    return await this.serializeIdentityTransition(project.path, async () => {
+      const current = await this.getConfig(project.id);
+      if (current.config.projectId === undefined) {
+        throw new CodingProjectServiceError(
+          409,
+          'CODING_PROJECT_IDENTITY_REQUIRED',
+          'A durable coding project identity is required',
+        );
+      }
+      const nextProjectId = resolveProjectIdentity(
+        { kind: 'create' },
+        this.options.createProjectId ?? randomUUID,
+      );
+      await this.options.onProjectIdentityChanging?.(
+        project,
+        current.config.projectId,
+        nextProjectId,
+      );
+      const next = {
+        ...current.config,
+        projectId: nextProjectId,
+        updatedAt: this.options.now?.() ?? new Date().toISOString(),
+      };
+      try {
+        await (this.options.writeConfig ?? writeCodingProjectConfigV2)(project.path, next);
+      } catch (error) {
+        storageFailure(error);
+      }
+      await this.options.onResourcesChanged?.(project);
+      return {
+        project: current.project,
+        config: next,
+        knowledgeFiles: await this.listKnowledgeFiles(current.project.path),
+      };
+    });
+  }
+
   async addKnowledgeFile(input: {
     projectId: string;
     fileName: string;
@@ -343,6 +542,21 @@ export class CodingProjectService {
     return { project, conversation };
   }
 
+  private serializeIdentityTransition<T>(
+    projectPath: string,
+    operation: () => Promise<T>,
+  ): Promise<T> {
+    const previous = this.identityTransitionTails.get(projectPath) ?? Promise.resolve();
+    const result = previous.then(operation, operation);
+    const tail = result.then(() => undefined, () => undefined);
+    this.identityTransitionTails.set(projectPath, tail);
+    return result.finally(() => {
+      if (this.identityTransitionTails.get(projectPath) === tail) {
+        this.identityTransitionTails.delete(projectPath);
+      }
+    });
+  }
+
   private async listKnowledgeFiles(projectPath: string): Promise<string[]> {
     try {
       const entries = await readdir(path.join(projectPath, 'knowledge'), { withFileTypes: true });
diff --git a/electron/coding-projects/project-store.ts b/electron/coding-projects/project-store.ts
index aefe4c6..4514480 100644
--- a/electron/coding-projects/project-store.ts
+++ b/electron/coding-projects/project-store.ts
@@ -196,12 +196,14 @@ export async function createLocalCodingProject(
   input: {
     projectPath: string;
     projectType?: ProjectType;
+    projectId?: string;
     now?: string;
   },
   store: CodingProjectStore,
 ): Promise<{ project: CodingProject; config: CodingProjectConfigV2 }> {
   const config = await createCodingProjectMetadata(input.projectPath, {
     projectType: input.projectType,
+    projectId: input.projectId,
     now: input.now,
   });
   const project = await store.openFolder(input.projectPath);
diff --git a/electron/coding-runtime/pi/release-proof.ts b/electron/coding-runtime/pi/release-proof.ts
index 9294949..23bd3e0 100644
--- a/electron/coding-runtime/pi/release-proof.ts
+++ b/electron/coding-runtime/pi/release-proof.ts
@@ -1436,7 +1436,10 @@ export async function startFinalAsarProxyCompositionProof(input: {
       PROXY_PROOF_MODEL_ID,
     ));
     await providerService.setDefaultAccount(PROOF_ACCOUNT_ID);
-    const project = await input.composition.projects.createProject({ projectPath: input.projectPath });
+    const project = await input.composition.projects.createProject({
+      projectPath: input.projectPath,
+      identity: { kind: 'create' },
+    });
     projectId = project.project.id;
     await createCodingProjectAgent(input.projectPath, {
       id: PROOF_AGENT_ID,
@@ -1777,7 +1780,10 @@ export async function startFinalAsarResilienceProof(input: {
         keepRecentTokens: 1,
       },
     }, null, 2), 'utf8');
-    const project = await input.composition.projects.createProject({ projectPath: input.projectPath });
+    const project = await input.composition.projects.createProject({
+      projectPath: input.projectPath,
+      identity: { kind: 'create' },
+    });
     projectId = project.project.id;
     await createCodingProjectAgent(input.projectPath, {
       id: PROOF_AGENT_ID,
diff --git a/shared/coding-project-contracts.ts b/shared/coding-project-contracts.ts
index 2ad514a..e5ea183 100644
--- a/shared/coding-project-contracts.ts
+++ b/shared/coding-project-contracts.ts
@@ -9,6 +9,10 @@ export interface CodingProjectSummary {
   lastOpenedAt: string;
 }
 
+export type ProjectIdentityChoice =
+  | { kind: 'create' }
+  | { kind: 'bind'; projectId: string };
+
 export interface CodingProjectAgent extends ConversationModelState {
   id: string;
   avatarId: string;
@@ -29,6 +33,7 @@ export interface CodingProjectAgent extends ConversationModelState {
 export interface CodingProjectConfig {
   schemaVersion: 2;
   projectType: ProjectType;
+  projectId?: string;
   initialized: boolean;
   agents: CodingProjectAgent[];
   knowledgeDirectory: 'knowledge';
diff --git a/tests/unit/coding-core-routes.test.ts b/tests/unit/coding-core-routes.test.ts
index b28cc80..0c6fc52 100644
--- a/tests/unit/coding-core-routes.test.ts
+++ b/tests/unit/coding-core-routes.test.ts
@@ -117,7 +117,10 @@ describe('PI-100 coding core Host contract', () => {
       },
     });
     try {
-      const created = await composition.projects.createProject({ projectPath });
+      const created = await composition.projects.createProject({
+        projectPath,
+        identity: { kind: 'create' },
+      });
       await createCodingProjectAgent(projectPath, {
         id: 'builder',
         avatarId: 'avatar-01',
@@ -682,7 +685,10 @@ describe('PI-100 coding core Host contract', () => {
     });
 
     const opened = await projects.openProject(projectRoots[1]!);
-    const created = await projects.createProject({ projectPath: projectRoots[2]! });
+    const created = await projects.createProject({
+      projectPath: projectRoots[2]!,
+      identity: { kind: 'create' },
+    });
     await projects.setActiveProject(first.project.id);
     await projects.removeProject(first.project.id);
 
@@ -716,7 +722,7 @@ describe('PI-100 coding core Host contract', () => {
       path: '/api/coding/projects/create',
       method: 'POST',
       headers: { 'content-type': 'application/json' },
-      body: JSON.stringify({ projectPath: createRoot }),
+      body: JSON.stringify({ projectPath: createRoot, identity: { kind: 'create' } }),
     }));
 
     for (const response of responses) {
diff --git a/tests/unit/coding-project-identity.test.ts b/tests/unit/coding-project-identity.test.ts
new file mode 100644
index 0000000..4d0b28a
--- /dev/null
+++ b/tests/unit/coding-project-identity.test.ts
@@ -0,0 +1,290 @@
+// @vitest-environment node
+
+import { copyFile, mkdir, mkdtemp, rename, rm, stat } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import path from 'node:path';
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import type { HostApiContext } from '../../electron/api/context';
+import { dispatchHostApiRequest } from '../../electron/api/host-api-dispatcher';
+import {
+  createCodingProjectConfigV2,
+  isCanonicalCodingProjectId,
+  normalizeCodingProjectConfigV2,
+  readCodingProjectConfigV2,
+  writeCodingProjectConfigV2,
+} from '../../electron/coding-projects/project-config';
+import { CodingProjectService } from '../../electron/coding-projects/project-service';
+import {
+  createCodingProjectStore,
+  createLocalCodingProject,
+  createMemoryCodingProjectStorage,
+  normalizeCodingProjectPath,
+} from '../../electron/coding-projects/project-store';
+
+const roots: string[] = [];
+const CREATED = '2026-08-26T00:00:00.000Z';
+const UPDATED = '2026-08-26T00:01:00.000Z';
+const PROJECT_ID = 'aaaaaaaa-aaaa-4aaa-8aaa-aaaaaaaaaaaa';
+const NEXT_PROJECT_ID = 'bbbbbbbb-bbbb-4bbb-8bbb-bbbbbbbbbbbb';
+
+afterEach(async () => {
+  await Promise.all(roots.splice(0).map((root) => rm(root, { recursive: true, force: true })));
+});
+
+async function makeRoot(prefix = 'makelore-project-identity-'): Promise<string> {
+  const root = await mkdtemp(path.join(tmpdir(), prefix));
+  roots.push(root);
+  return root;
+}
+
+function makeStore(localId = 'local-project-id') {
+  return createCodingProjectStore(createMemoryCodingProjectStorage(), {
+    createId: () => localId,
+    now: () => CREATED,
+  });
+}
+
+describe('coding project durable identity', () => {
+  it('preserves canonical identity and rejects noncanonical values without backfill', () => {
+    const initialized = createCodingProjectConfigV2(CREATED, 'custom', PROJECT_ID);
+    expect(initialized.projectId).toBe(PROJECT_ID);
+    expect(isCanonicalCodingProjectId(PROJECT_ID)).toBe(true);
+
+    const legacy = createCodingProjectConfigV2(CREATED, 'custom');
+    expect(legacy).not.toHaveProperty('projectId');
+    expect(normalizeCodingProjectConfigV2(legacy)).not.toHaveProperty('projectId');
+
+    for (const projectId of [
+      PROJECT_ID.toUpperCase(),
+      `{${PROJECT_ID}}`,
+      PROJECT_ID.replaceAll('-', ''),
+      ` ${PROJECT_ID}`,
+      'not-a-project-id',
+      null,
+    ]) {
+      expect(() => normalizeCodingProjectConfigV2({ ...legacy, projectId }))
+        .toThrow('Project identity is invalid');
+    }
+  });
+
+  it('requires an explicit create/bind choice and writes no config on invalid bind', async () => {
+    const projectPath = await makeRoot();
+    const store = makeStore();
+    const createProjectId = vi.fn(() => PROJECT_ID);
+    const identityChanging = vi.fn();
+    const projects = new CodingProjectService(store, {
+      createProjectId,
+      onProjectIdentityChanging: identityChanging,
+    });
+
+    const created = await projects.createProject({
+      projectPath,
+      identity: { kind: 'create' },
+    });
+    expect(created.config.projectId).toBe(PROJECT_ID);
+    expect(createProjectId).toHaveBeenCalledTimes(1);
+    expect(identityChanging).not.toHaveBeenCalled();
+
+    const invalidPath = path.join(await makeRoot('makelore-project-identity-parent-'), 'invalid');
+    await expect(projects.createProject({
+      projectPath: invalidPath,
+      identity: { kind: 'bind', projectId: 'not-canonical' },
+    })).rejects.toMatchObject({
+      code: 'CODING_PROJECT_REQUEST_INVALID',
+      status: 400,
+    });
+    await expect(readCodingProjectConfigV2(invalidPath)).resolves.toEqual({ status: 'missing' });
+    await expect(stat(invalidPath)).rejects.toMatchObject({ code: 'ENOENT' });
+
+    const boundPath = await makeRoot();
+    const bound = await projects.createProject({
+      projectPath: boundPath,
+      identity: { kind: 'bind', projectId: NEXT_PROJECT_ID },
+    });
+    expect(bound.config.projectId).toBe(NEXT_PROJECT_ID);
+    expect(createProjectId).toHaveBeenCalledTimes(1);
+  });
+
+  it('resolves a legacy identity once and invalidates before writing resources', async () => {
+    const projectPath = await makeRoot();
+    const store = makeStore();
+    const local = await createLocalCodingProject({ projectPath, now: CREATED }, store);
+    const events: string[] = [];
+    const projects = new CodingProjectService(store, {
+      createProjectId: () => PROJECT_ID,
+      now: () => UPDATED,
+      onProjectIdentityChanging: () => { events.push('invalidate'); },
+      writeConfig: async (filePath, value) => {
+        events.push('write');
+        await writeCodingProjectConfigV2(filePath, value);
+      },
+      onResourcesChanged: () => { events.push('resources'); },
+    });
+
+    expect(local.config).not.toHaveProperty('projectId');
+    const resolved = await projects.resolveProjectIdentity(local.project.id, { kind: 'create' });
+    expect(resolved.config.projectId).toBe(PROJECT_ID);
+    expect(events).toEqual(['invalidate', 'write', 'resources']);
+    await expect(projects.resolveProjectIdentity(local.project.id, {
+      kind: 'bind',
+      projectId: NEXT_PROJECT_ID,
+    })).rejects.toMatchObject({
+      code: 'CODING_PROJECT_IDENTITY_IMMUTABLE',
+      status: 409,
+    });
+    expect((await projects.getConfig(local.project.id)).config.projectId).toBe(PROJECT_ID);
+  });
+
+  it('keeps ordinary saves immutable and supports a confirmed independent copy', async () => {
+    const projectPath = await makeRoot();
+    const store = makeStore();
+    const local = await createLocalCodingProject({
+      projectPath,
+      projectId: PROJECT_ID,
+      now: CREATED,
+    }, store);
+    const invalidating = vi.fn();
+    const projects = new CodingProjectService(store, {
+      createProjectId: () => NEXT_PROJECT_ID,
+      now: () => UPDATED,
+      onProjectIdentityChanging: invalidating,
+    });
+    const current = await projects.getConfig(local.project.id);
+
+    await expect(projects.saveConfig(local.project.id, {
+      ...current.config,
+      projectId: undefined,
+    })).rejects.toMatchObject({ code: 'CODING_PROJECT_IDENTITY_IMMUTABLE', status: 409 });
+    await expect(projects.saveConfig(local.project.id, {
+      ...current.config,
+      projectId: NEXT_PROJECT_ID,
+    })).rejects.toMatchObject({ code: 'CODING_PROJECT_IDENTITY_IMMUTABLE', status: 409 });
+
+    await expect(projects.makeProjectIndependentCopy(
+      local.project.id,
+      false as unknown as true,
+    )).rejects.toMatchObject({
+      code: 'CODING_PROJECT_IDENTITY_CONFIRMATION_REQUIRED',
+      status: 400,
+    });
+    const independent = await projects.makeProjectIndependentCopy(local.project.id, true);
+    expect(independent.config.projectId).toBe(NEXT_PROJECT_ID);
+    expect(independent.config.updatedAt).toBe(UPDATED);
+    expect(invalidating).toHaveBeenCalledWith(local.project, PROJECT_ID, NEXT_PROJECT_ID);
+  });
+
+  it('does not write a legacy identity when preview invalidation fails', async () => {
+    const projectPath = await makeRoot();
+    const store = makeStore();
+    const local = await createLocalCodingProject({ projectPath }, store);
+    const projects = new CodingProjectService(store, {
+      createProjectId: () => PROJECT_ID,
+      onProjectIdentityChanging: () => {
+        throw new Error('preview close failed');
+      },
+    });
+
+    await expect(projects.resolveProjectIdentity(local.project.id, { kind: 'create' }))
+      .rejects.toThrow('preview close failed');
+    const current = await readCodingProjectConfigV2(projectPath);
+    expect(current).toMatchObject({ status: 'valid', config: { projectType: 'custom' } });
+    if (current.status === 'valid') expect(current.config).not.toHaveProperty('projectId');
+  });
+
+  it('retains identity across a move and raw folder copy', async () => {
+    const parent = await makeRoot('makelore-project-identity-move-parent-');
+    const originalPath = path.join(parent, 'original');
+    await mkdir(originalPath);
+    const store = makeStore();
+    const original = await createLocalCodingProject({
+      projectPath: originalPath,
+      projectId: PROJECT_ID,
+      now: CREATED,
+    }, store);
+
+    const movedPath = path.join(parent, 'moved');
+    await rename(originalPath, movedPath);
+    const movedStore = makeStore('moved-local-project-id');
+    const moved = await movedStore.openFolder(movedPath);
+    expect((await readCodingProjectConfigV2(moved.path)).status).toBe('valid');
+    const movedConfig = await readCodingProjectConfigV2(moved.path);
+    expect(movedConfig).toMatchObject({ status: 'valid', config: { projectId: PROJECT_ID } });
+
+    const copiedPath = path.join(parent, 'copied');
+    await mkdir(path.join(copiedPath, '.niancode'), { recursive: true });
+    await copyFile(
+      path.join(movedPath, '.niancode', 'project.json'),
+      path.join(copiedPath, '.niancode', 'project.json'),
+    );
+    const copied = await readCodingProjectConfigV2(copiedPath);
+    expect(copied).toMatchObject({ status: 'valid', config: { projectId: PROJECT_ID } });
+    expect(original.project.id).not.toBe(moved.id);
+  });
+
+  it('centralizes the active real path and durable identity checks', async () => {
+    const projectPath = await makeRoot();
+    const store = makeStore();
+    const local = await createLocalCodingProject({ projectPath, projectId: PROJECT_ID }, store);
+    const projects = new CodingProjectService(store);
+
+    const active = await projects.requireActiveRealProjectWithIdentity(projectPath);
+    expect(active).toMatchObject({ project: local.project, projectId: PROJECT_ID });
+    expect(normalizeCodingProjectPath(active.path)).toBe(normalizeCodingProjectPath(local.project.path));
+    const otherPath = await makeRoot('makelore-project-identity-other-');
+    await expect(projects.requireActiveRealProjectWithIdentity(otherPath)).rejects.toMatchObject({
+      code: 'CODING_ACTIVE_PROJECT_PATH_MISMATCH',
+      status: 409,
+    });
+
+    const legacyPath = await makeRoot('makelore-project-identity-legacy-');
+    const legacyStore = makeStore();
+    await createLocalCodingProject({ projectPath: legacyPath }, legacyStore);
+    await expect(new CodingProjectService(legacyStore).requireActiveRealProjectWithIdentity())
+      .rejects.toMatchObject({ code: 'CODING_PROJECT_IDENTITY_REQUIRED', status: 409 });
+  });
+
+  it('exposes identity resolution and independent-copy through the Host routes', async () => {
+    const projectPath = await makeRoot();
+    const store = makeStore();
+    const local = await createLocalCodingProject({ projectPath }, store);
+    const generatedIds = [PROJECT_ID, NEXT_PROJECT_ID];
+    const projects = new CodingProjectService(store, {
+      createProjectId: () => generatedIds.shift() ?? 'cccccccc-cccc-4ccc-8ccc-cccccccccccc',
+    });
+    const context = {
+      codingProducts: { projects, conversations: {} },
+    } as unknown as HostApiContext;
+
+    const resolved = await dispatchHostApiRequest(context, {
+      path: '/api/coding/projects/identity',
+      method: 'POST',
+      headers: { 'content-type': 'application/json' },
+      body: JSON.stringify({ localProjectId: local.project.id, identity: { kind: 'create' } }),
+    });
+    expect(resolved).toMatchObject({
+      status: 200,
+      json: { snapshot: { config: { projectId: PROJECT_ID } } },
+    });
+
+    const independent = await dispatchHostApiRequest(context, {
+      path: '/api/coding/projects/identity/independent-copy',
+      method: 'POST',
+      headers: { 'content-type': 'application/json' },
+      body: JSON.stringify({ localProjectId: local.project.id, confirmed: true }),
+    });
+    expect(independent.status).toBe(200);
+    expect((independent.json as { snapshot: { config: { projectId: string } } }).snapshot.config.projectId)
+      .not.toBe(PROJECT_ID);
+
+    const rejected = await dispatchHostApiRequest(context, {
+      path: '/api/coding/projects/identity/independent-copy',
+      method: 'POST',
+      headers: { 'content-type': 'application/json' },
+      body: JSON.stringify({ localProjectId: local.project.id, confirmed: false }),
+    });
+    expect(rejected).toMatchObject({
+      status: 400,
+      json: { code: 'CODING_PROJECT_IDENTITY_CONFIRMATION_REQUIRED' },
+    });
+  });
+});
diff --git a/tests/unit/coding-projects-migration.test.ts b/tests/unit/coding-projects-migration.test.ts
index 0d02816..b995678 100644
--- a/tests/unit/coding-projects-migration.test.ts
+++ b/tests/unit/coding-projects-migration.test.ts
@@ -177,6 +177,7 @@ describe('coding project v1 to v2 migration', () => {
 
     expect(result.status).toBe('migrated');
     if (result.status !== 'migrated') throw new Error('Expected migrated result');
+    expect(result.config).not.toHaveProperty('projectId');
     expect(result.config.agents).toEqual([
       expect.objectContaining({
         id: 'unique',