diff --git a/apps/server/execution/orchestrator.test.ts b/apps/server/execution/orchestrator.test.ts
index 6cf293d..ebf6ea2 100644
--- a/apps/server/execution/orchestrator.test.ts
+++ b/apps/server/execution/orchestrator.test.ts
@@ -46,6 +46,8 @@ function createMocks() {
     ensureBranch: vi.fn(),
     mergeBranch: vi.fn().mockResolvedValue({ success: true, message: 'merged', previousRef: 'abc000' }),
     diffBranches: vi.fn().mockResolvedValue(''),
+    diffBranchesStat: vi.fn().mockResolvedValue([]),
+    diffFileSingle: vi.fn().mockResolvedValue(''),
     deleteBranch: vi.fn(),
     branchExists: vi.fn().mockResolvedValue(true),
     remoteBranchExists: vi.fn().mockResolvedValue(false),
diff --git a/apps/server/git/branch-manager.ts b/apps/server/git/branch-manager.ts
index 9ba6d85..dc7d174 100644
--- a/apps/server/git/branch-manager.ts
+++ b/apps/server/git/branch-manager.ts
@@ -6,7 +6,7 @@
  * a worktree to be checked out.
  */
 
-import type { MergeResult, MergeabilityResult, BranchCommit } from './types.js';
+import type { MergeResult, MergeabilityResult, BranchCommit, FileStatEntry } from './types.js';
 
 export interface BranchManager {
   /**
@@ -29,6 +29,22 @@ export interface BranchManager {
    */
   diffBranches(repoPath: string, baseBranch: string, headBranch: string): Promise<string>;
 
+  /**
+   * Get per-file metadata for changes between two branches.
+   * Uses three-dot diff (baseBranch...headBranch) — same divergence model as diffBranches.
+   * Binary files are included with status 'binary' and additions/deletions both 0.
+   * Does NOT return hunk content.
+   */
+  diffBranchesStat(repoPath: string, baseBranch: string, headBranch: string): Promise<FileStatEntry[]>;
+
+  /**
+   * Get the raw unified diff for a single file between two branches.
+   * Uses three-dot diff (baseBranch...headBranch).
+   * Returns empty string for binary files (caller must detect binary separately).
+   * filePath must be URL-decoded before being passed here.
+   */
+  diffFileSingle(repoPath: string, baseBranch: string, headBranch: string, filePath: string): Promise<string>;
+
   /**
    * Delete a branch. No-op if the branch doesn't exist.
    */
diff --git a/apps/server/git/simple-git-branch-manager.test.ts b/apps/server/git/simple-git-branch-manager.test.ts
index 18cb50a..f59c65b 100644
--- a/apps/server/git/simple-git-branch-manager.test.ts
+++ b/apps/server/git/simple-git-branch-manager.test.ts
@@ -65,6 +65,69 @@ async function createTestRepoWithRemote(): Promise<{
   };
 }
 
+/**
+ * Create a repo pair for testing diff operations.
+ * Sets up bare + clone with a 'feature' branch that has known changes vs 'main'.
+ */
+async function createTestRepoForDiff(): Promise<{
+  clonePath: string;
+  cleanup: () => Promise<void>;
+}> {
+  const tmpBase = await mkdtemp(path.join(tmpdir(), 'cw-diff-test-'));
+  const barePath = path.join(tmpBase, 'bare.git');
+  const workPath = path.join(tmpBase, 'work');
+  const clonePath = path.join(tmpBase, 'clone');
+
+  // Create bare repo
+  await simpleGit().init([barePath, '--bare']);
+
+  // Set up main branch in work dir
+  await simpleGit().clone(barePath, workPath);
+  const workGit = simpleGit(workPath);
+  await workGit.addConfig('user.email', 'test@example.com');
+  await workGit.addConfig('user.name', 'Test User');
+  await writeFile(path.join(workPath, 'README.md'), '# README\n');
+  await writeFile(path.join(workPath, 'to-delete.txt'), 'delete me\n');
+  await workGit.add(['README.md', 'to-delete.txt']);
+  await workGit.commit('Initial commit');
+  await workGit.push('origin', 'main');
+
+  // Clone and create feature branch with changes
+  await simpleGit().clone(barePath, clonePath);
+  const cloneGit = simpleGit(clonePath);
+  await cloneGit.addConfig('user.email', 'test@example.com');
+  await cloneGit.addConfig('user.name', 'Test User');
+  await cloneGit.checkoutLocalBranch('feature');
+
+  // Add new text file
+  await writeFile(path.join(clonePath, 'added.txt'), 'new content\n');
+  await cloneGit.add('added.txt');
+
+  // Modify existing file
+  await writeFile(path.join(clonePath, 'README.md'), '# README\n\nModified content\n');
+  await cloneGit.add('README.md');
+
+  // Delete a file
+  await cloneGit.rm(['to-delete.txt']);
+
+  // Add binary file
+  await writeFile(path.join(clonePath, 'image.bin'), Buffer.alloc(16));
+  await cloneGit.add('image.bin');
+
+  // Add file with space in name
+  await writeFile(path.join(clonePath, 'has space.txt'), 'content\n');
+  await cloneGit.add('has space.txt');
+
+  await cloneGit.commit('Feature branch changes');
+
+  return {
+    clonePath,
+    cleanup: async () => {
+      await rm(tmpBase, { recursive: true, force: true });
+    },
+  };
+}
+
 describe('SimpleGitBranchManager', () => {
   let clonePath: string;
   let cleanup: () => Promise<void>;
@@ -108,3 +171,80 @@ describe('SimpleGitBranchManager', () => {
     });
   });
 });
+
+describe('SimpleGitBranchManager - diffBranchesStat and diffFileSingle', () => {
+  let clonePath: string;
+  let cleanup: () => Promise<void>;
+  let branchManager: SimpleGitBranchManager;
+
+  beforeEach(async () => {
+    const setup = await createTestRepoForDiff();
+    clonePath = setup.clonePath;
+    cleanup = setup.cleanup;
+    branchManager = new SimpleGitBranchManager();
+  });
+
+  afterEach(async () => {
+    await cleanup();
+  });
+
+  describe('diffBranchesStat', () => {
+    it('returns correct entries for added, modified, and deleted text files', async () => {
+      const entries = await branchManager.diffBranchesStat(clonePath, 'main', 'feature');
+      const added = entries.find(e => e.path === 'added.txt');
+      const modified = entries.find(e => e.path === 'README.md');
+      const deleted = entries.find(e => e.path === 'to-delete.txt');
+
+      expect(added?.status).toBe('added');
+      expect(added?.additions).toBeGreaterThan(0);
+      expect(modified?.status).toBe('modified');
+      expect(deleted?.status).toBe('deleted');
+      expect(deleted?.deletions).toBeGreaterThan(0);
+    });
+
+    it('marks binary files as status=binary with additions=0, deletions=0', async () => {
+      const entries = await branchManager.diffBranchesStat(clonePath, 'main', 'feature');
+      const binary = entries.find(e => e.path === 'image.bin');
+      expect(binary?.status).toBe('binary');
+      expect(binary?.additions).toBe(0);
+      expect(binary?.deletions).toBe(0);
+    });
+
+    it('returns empty array when there are no changes', async () => {
+      const entries = await branchManager.diffBranchesStat(clonePath, 'main', 'main');
+      expect(entries).toEqual([]);
+    });
+
+    it('handles files with spaces in their names', async () => {
+      const entries = await branchManager.diffBranchesStat(clonePath, 'main', 'feature');
+      const spaced = entries.find(e => e.path === 'has space.txt');
+      expect(spaced).toBeDefined();
+      expect(spaced?.status).toBe('added');
+    });
+  });
+
+  describe('diffFileSingle', () => {
+    it('returns unified diff containing addition hunks for an added file', async () => {
+      const diff = await branchManager.diffFileSingle(clonePath, 'main', 'feature', 'added.txt');
+      expect(diff).toContain('+');
+      expect(diff).toContain('added.txt');
+    });
+
+    it('returns unified diff with removal hunks for a deleted file', async () => {
+      const diff = await branchManager.diffFileSingle(clonePath, 'main', 'feature', 'to-delete.txt');
+      expect(diff).toContain('-');
+      expect(diff).toContain('to-delete.txt');
+    });
+
+    it('returns string for a binary file', async () => {
+      const diff = await branchManager.diffFileSingle(clonePath, 'main', 'feature', 'image.bin');
+      // git diff returns empty or a "Binary files differ" line — no hunk content
+      expect(typeof diff).toBe('string');
+    });
+
+    it('handles file paths with spaces', async () => {
+      const diff = await branchManager.diffFileSingle(clonePath, 'main', 'feature', 'has space.txt');
+      expect(diff).toContain('has space.txt');
+    });
+  });
+});
diff --git a/apps/server/git/simple-git-branch-manager.ts b/apps/server/git/simple-git-branch-manager.ts
index 47b690e..7e96848 100644
--- a/apps/server/git/simple-git-branch-manager.ts
+++ b/apps/server/git/simple-git-branch-manager.ts
@@ -11,11 +11,31 @@ import { mkdtempSync, rmSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { simpleGit } from 'simple-git';
 import type { BranchManager } from './branch-manager.js';
-import type { MergeResult, MergeabilityResult, BranchCommit } from './types.js';
+import type { MergeResult, MergeabilityResult, BranchCommit, FileStatEntry } from './types.js';
 import { createModuleLogger } from '../logger/index.js';
 
 const log = createModuleLogger('branch-manager');
 
+/**
+ * Normalize a numstat path to the new path for rename entries.
+ * Handles patterns like:
+ *   - "{old.txt => new.txt}" → "new.txt"
+ *   - "dir/{old.txt => new.txt}" → "dir/new.txt"
+ *   - "old_dir/file.txt => new_dir/file.txt" → "new_dir/file.txt"
+ */
+function normalizeNumstatPath(pathStr: string): string {
+  const braceMatch = pathStr.match(/^(.*)\{(.*) => (.*)\}(.*)$/);
+  if (braceMatch) {
+    const [, prefix, , newPart, suffix] = braceMatch;
+    return `${prefix}${newPart}${suffix}`;
+  }
+  const arrowMatch = pathStr.match(/^.* => (.+)$/);
+  if (arrowMatch) {
+    return arrowMatch[1];
+  }
+  return pathStr;
+}
+
 export class SimpleGitBranchManager implements BranchManager {
   async ensureBranch(repoPath: string, branch: string, baseBranch: string): Promise<void> {
     const git = simpleGit(repoPath);
@@ -97,6 +117,91 @@ export class SimpleGitBranchManager implements BranchManager {
     return diff;
   }
 
+  async diffBranchesStat(repoPath: string, baseBranch: string, headBranch: string): Promise<FileStatEntry[]> {
+    const git = simpleGit(repoPath);
+    const range = `${baseBranch}...${headBranch}`;
+
+    const [nameStatusRaw, numStatRaw] = await Promise.all([
+      git.raw(['diff', '--name-status', range]),
+      git.raw(['diff', '--numstat', range]),
+    ]);
+
+    if (!nameStatusRaw.trim()) return [];
+
+    // Parse numstat: "<additions>\t<deletions>\t<path>"
+    // Binary files: "-\t-\t<path>"
+    const numStatMap = new Map<string, { additions: number; deletions: number; binary: boolean }>();
+    for (const line of numStatRaw.split('\n')) {
+      if (!line.trim()) continue;
+      const tabIdx1 = line.indexOf('\t');
+      const tabIdx2 = line.indexOf('\t', tabIdx1 + 1);
+      if (tabIdx1 === -1 || tabIdx2 === -1) continue;
+      const addStr = line.slice(0, tabIdx1);
+      const delStr = line.slice(tabIdx1 + 1, tabIdx2);
+      const pathStr = line.slice(tabIdx2 + 1);
+      const binary = addStr === '-' && delStr === '-';
+      // Normalize rename paths like "{old => new}" or "dir/{old => new}/file" to new path
+      const newPath = normalizeNumstatPath(pathStr);
+      numStatMap.set(newPath, {
+        additions: binary ? 0 : parseInt(addStr, 10),
+        deletions: binary ? 0 : parseInt(delStr, 10),
+        binary,
+      });
+    }
+
+    // Parse name-status: "<status>\t<path>" or "<Rxx>\t<oldPath>\t<newPath>"
+    const entries: FileStatEntry[] = [];
+    for (const line of nameStatusRaw.split('\n')) {
+      if (!line.trim()) continue;
+      const parts = line.split('\t');
+      if (parts.length < 2) continue;
+
+      const statusCode = parts[0];
+      let status: FileStatEntry['status'];
+      let filePath: string;
+      let oldPath: string | undefined;
+
+      if (statusCode.startsWith('R')) {
+        status = 'renamed';
+        oldPath = parts[1];
+        filePath = parts[2];
+      } else if (statusCode === 'A') {
+        status = 'added';
+        filePath = parts[1];
+      } else if (statusCode === 'M') {
+        status = 'modified';
+        filePath = parts[1];
+      } else if (statusCode === 'D') {
+        status = 'deleted';
+        filePath = parts[1];
+      } else {
+        status = 'modified';
+        filePath = parts[1];
+      }
+
+      const numStat = numStatMap.get(filePath);
+      if (numStat?.binary) {
+        status = 'binary';
+      }
+
+      const entry: FileStatEntry = {
+        path: filePath,
+        status,
+        additions: numStat?.additions ?? 0,
+        deletions: numStat?.deletions ?? 0,
+      };
+      if (oldPath !== undefined) entry.oldPath = oldPath;
+      entries.push(entry);
+    }
+
+    return entries;
+  }
+
+  async diffFileSingle(repoPath: string, baseBranch: string, headBranch: string, filePath: string): Promise<string> {
+    const git = simpleGit(repoPath);
+    return git.diff([`${baseBranch}...${headBranch}`, '--', filePath]);
+  }
+
   async deleteBranch(repoPath: string, branch: string): Promise<void> {
     const git = simpleGit(repoPath);
     const exists = await this.branchExists(repoPath, branch);
diff --git a/apps/server/git/types.ts b/apps/server/git/types.ts
index 51a35b7..00cb829 100644
--- a/apps/server/git/types.ts
+++ b/apps/server/git/types.ts
@@ -100,6 +100,29 @@ export interface BranchCommit {
   deletions: number;
 }
 
+// =============================================================================
+// File Stat Entry (per-file diff metadata)
+// =============================================================================
+
+/**
+ * Metadata for a single file changed between two branches.
+ * No hunk content — only path, status, and line-count statistics.
+ */
+export interface FileStatEntry {
+  /** New path (or old path for deletions) */
+  path: string;
+  /** Only set for renames — the path before the rename */
+  oldPath?: string;
+  /** Nature of the change */
+  status: 'added' | 'modified' | 'deleted' | 'renamed' | 'binary';
+  /** Lines added (0 for binary files) */
+  additions: number;
+  /** Lines deleted (0 for binary files) */
+  deletions: number;
+  /** Which project clone this file belongs to (populated by callers in multi-project scenarios) */
+  projectId?: string;
+}
+
 // =============================================================================
 // WorktreeManager Port Interface
 // =============================================================================
diff --git a/docs/git-process-logging.md b/docs/git-process-logging.md
index 2e5d8c4..16968af 100644
--- a/docs/git-process-logging.md
+++ b/docs/git-process-logging.md
@@ -40,6 +40,8 @@ Worktrees stored in `.cw-worktrees/` subdirectory of the repo. Each agent gets a
 | `ensureBranch(repoPath, branch, baseBranch)` | Create branch from base if it doesn't exist (idempotent) |
 | `mergeBranch(repoPath, source, target)` | Merge via ephemeral worktree, returns conflict info |
 | `diffBranches(repoPath, base, head)` | Three-dot diff between branches |
+| `diffBranchesStat(repoPath, base, head)` | Per-file metadata (path, status, additions, deletions) — no hunk content. Binary files included with `status: 'binary'` and counts of 0. Returns `FileStatEntry[]`. |
+| `diffFileSingle(repoPath, base, head, filePath)` | Raw unified diff for a single file (three-dot diff). `filePath` must be URL-decoded. Returns empty string for binary files. |
 | `deleteBranch(repoPath, branch)` | Delete local branch (no-op if missing) |
 | `branchExists(repoPath, branch)` | Check local branches |
 | `remoteBranchExists(repoPath, branch)` | Check remote tracking branches (`origin/<branch>`) |