diff --git a/lib/sandbox/__tests__/createSandboxHandler.test.ts b/lib/sandbox/__tests__/createSandboxHandler.test.ts
index 2bf048a1..c48b0cb5 100644
--- a/lib/sandbox/__tests__/createSandboxHandler.test.ts
+++ b/lib/sandbox/__tests__/createSandboxHandler.test.ts
@@ -10,10 +10,14 @@ import { installSessionGlobalSkills } from "@/lib/sandbox/installSessionGlobalSk
 import { findOrgSnapshot } from "@/lib/sandbox/findOrgSnapshot";
 import { kickBuildOrgSnapshotWorkflow } from "@/lib/sandbox/kickBuildOrgSnapshotWorkflow";
 import { kickSandboxLifecycleWorkflow } from "@/lib/sandbox/kickSandboxLifecycleWorkflow";
+import { resolveGitUser } from "@/lib/sandbox/resolveGitUser";
 
 vi.mock("@/lib/networking/getCorsHeaders", () => ({
   getCorsHeaders: () => ({ "Access-Control-Allow-Origin": "*" }),
 }));
+vi.mock("@/lib/sandbox/resolveGitUser", () => ({
+  resolveGitUser: vi.fn(),
+}));
 vi.mock("@/lib/sandbox/validateCreateSandboxBody", () => ({
   validateCreateSandboxBody: vi.fn(),
 }));
@@ -73,6 +77,23 @@ describe("createSandboxHandler", () => {
       fakeSandbox() as unknown as Awaited<ReturnType<typeof connectSandbox>>,
     );
     vi.mocked(updateSession).mockResolvedValue({} as any);
+    vi.mocked(resolveGitUser).mockResolvedValue({
+      name: "Ada Lovelace",
+      email: "ada@example.com",
+    });
+  });
+
+  it("passes the resolved gitUser through to connectSandbox", async () => {
+    await createSandboxHandler(makeReq());
+
+    expect(resolveGitUser).toHaveBeenCalledWith(ACCOUNT_ID);
+    const args = vi.mocked(connectSandbox).mock.calls[0]?.[0] as {
+      options?: { gitUser?: { name: string; email: string } };
+    };
+    expect(args.options?.gitUser).toEqual({
+      name: "Ada Lovelace",
+      email: "ada@example.com",
+    });
   });
 
   it("short-circuits with the validator's response on validation failure", async () => {
diff --git a/lib/sandbox/__tests__/resolveGitUser.test.ts b/lib/sandbox/__tests__/resolveGitUser.test.ts
new file mode 100644
index 00000000..04aef07f
--- /dev/null
+++ b/lib/sandbox/__tests__/resolveGitUser.test.ts
@@ -0,0 +1,83 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { resolveGitUser } from "@/lib/sandbox/resolveGitUser";
+import { selectAccounts } from "@/lib/supabase/accounts/selectAccounts";
+import selectAccountEmails from "@/lib/supabase/account_emails/selectAccountEmails";
+
+vi.mock("@/lib/supabase/accounts/selectAccounts", () => ({
+  selectAccounts: vi.fn(),
+}));
+vi.mock("@/lib/supabase/account_emails/selectAccountEmails", () => ({
+  default: vi.fn(),
+}));
+
+const ACCOUNT_ID = "11111111-2222-3333-4444-555555555555";
+
+describe("resolveGitUser", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("uses the account's name and email when both are populated", async () => {
+    vi.mocked(selectAccounts).mockResolvedValueOnce([
+      { id: ACCOUNT_ID, name: "Ada Lovelace", timestamp: null },
+    ] as never);
+    vi.mocked(selectAccountEmails).mockResolvedValueOnce([
+      { id: "e1", account_id: ACCOUNT_ID, email: "ada@example.com", updated_at: "" },
+    ] as never);
+
+    const gitUser = await resolveGitUser(ACCOUNT_ID);
+
+    expect(gitUser).toEqual({ name: "Ada Lovelace", email: "ada@example.com" });
+  });
+
+  it("falls back to a stable synthetic name when the account has no name", async () => {
+    vi.mocked(selectAccounts).mockResolvedValueOnce([
+      { id: ACCOUNT_ID, name: null, timestamp: null },
+    ] as never);
+    vi.mocked(selectAccountEmails).mockResolvedValueOnce([
+      { id: "e1", account_id: ACCOUNT_ID, email: "ada@example.com", updated_at: "" },
+    ] as never);
+
+    const gitUser = await resolveGitUser(ACCOUNT_ID);
+
+    expect(gitUser.name).toBe(`recoupable-${ACCOUNT_ID.slice(0, 8)}`);
+    expect(gitUser.email).toBe("ada@example.com");
+  });
+
+  it("falls back to a noreply email when no account_emails row exists", async () => {
+    vi.mocked(selectAccounts).mockResolvedValueOnce([
+      { id: ACCOUNT_ID, name: "Ada Lovelace", timestamp: null },
+    ] as never);
+    vi.mocked(selectAccountEmails).mockResolvedValueOnce([] as never);
+
+    const gitUser = await resolveGitUser(ACCOUNT_ID);
+
+    expect(gitUser.name).toBe("Ada Lovelace");
+    expect(gitUser.email).toBe(`${ACCOUNT_ID}@users.noreply.recoupable.com`);
+  });
+
+  it("falls back on both fields when nothing is on file", async () => {
+    vi.mocked(selectAccounts).mockResolvedValueOnce([] as never);
+    vi.mocked(selectAccountEmails).mockResolvedValueOnce([] as never);
+
+    const gitUser = await resolveGitUser(ACCOUNT_ID);
+
+    expect(gitUser).toEqual({
+      name: `recoupable-${ACCOUNT_ID.slice(0, 8)}`,
+      email: `${ACCOUNT_ID}@users.noreply.recoupable.com`,
+    });
+  });
+
+  it("ignores account_emails rows where email is null", async () => {
+    vi.mocked(selectAccounts).mockResolvedValueOnce([
+      { id: ACCOUNT_ID, name: "Ada Lovelace", timestamp: null },
+    ] as never);
+    vi.mocked(selectAccountEmails).mockResolvedValueOnce([
+      { id: "e1", account_id: ACCOUNT_ID, email: null, updated_at: "" },
+    ] as never);
+
+    const gitUser = await resolveGitUser(ACCOUNT_ID);
+
+    expect(gitUser.email).toBe(`${ACCOUNT_ID}@users.noreply.recoupable.com`);
+  });
+});
diff --git a/lib/sandbox/createSandboxHandler.ts b/lib/sandbox/createSandboxHandler.ts
index 399126d1..83922877 100644
--- a/lib/sandbox/createSandboxHandler.ts
+++ b/lib/sandbox/createSandboxHandler.ts
@@ -9,6 +9,7 @@ import { getSessionSandboxName } from "@/lib/sandbox/getSessionSandboxName";
 import { installSessionGlobalSkills } from "@/lib/sandbox/installSessionGlobalSkills";
 import { kickBuildOrgSnapshotWorkflow } from "@/lib/sandbox/kickBuildOrgSnapshotWorkflow";
 import { kickSandboxLifecycleWorkflow } from "@/lib/sandbox/kickSandboxLifecycleWorkflow";
+import { resolveGitUser } from "@/lib/sandbox/resolveGitUser";
 import { extractOrgRepoName } from "@/lib/recoupable/extractOrgRepoName";
 import { updateSession } from "@/lib/supabase/sessions/updateSession";
 import { getServiceGithubToken } from "@/lib/github/getServiceGithubToken";
@@ -82,6 +83,12 @@ export async function createSandboxHandler(request: NextRequest): Promise<NextRe
 
   const startTime = Date.now();
 
+  // Per-account `gitUser` controls commit authorship inside the sandbox
+  // (`git config user.name` / `user.email`). The push credential is a
+  // separate hardcoded service token — `gitUser` is purely about who
+  // each commit object is *authored* by.
+  const gitUser = await resolveGitUser(auth.accountId);
+
   let sandbox;
   try {
     sandbox = await connectSandbox({
@@ -100,6 +107,7 @@ export async function createSandboxHandler(request: NextRequest): Promise<NextRe
         timeout: DEFAULT_TIMEOUT_MS,
         ports: DEFAULT_PORTS,
         githubToken: getServiceGithubToken(),
+        gitUser,
         ...(orgSnapshotId ? { baseSnapshotId: orgSnapshotId } : {}),
         persistent: !!sandboxName,
         resume: !!sandboxName,
diff --git a/lib/sandbox/resolveGitUser.ts b/lib/sandbox/resolveGitUser.ts
new file mode 100644
index 00000000..12d3d027
--- /dev/null
+++ b/lib/sandbox/resolveGitUser.ts
@@ -0,0 +1,39 @@
+import selectAccountEmails from "@/lib/supabase/account_emails/selectAccountEmails";
+import { selectAccounts } from "@/lib/supabase/accounts/selectAccounts";
+
+interface GitUser {
+  name: string;
+  email: string;
+}
+
+/**
+ * Resolves the per-account `gitUser` identity that the sandbox should
+ * use for `git config user.name` / `user.email`. Driven by:
+ *   - `accounts.name` for the display name
+ *   - `account_emails.email` for the address
+ *
+ * When either field is missing, falls back to a synthetic value derived
+ * from the account id. This keeps commit attribution consistent across
+ * sandbox restores without leaking PII when the account row is sparse.
+ *
+ * Note: this controls *commit authorship* only. The push credential
+ * (the GitHub token) is a single hardcoded service token issued via
+ * `getServiceGithubToken` and is unrelated.
+ *
+ * @param accountId - The authenticated account id.
+ * @returns A `{ name, email }` pair safe to pass to `connectSandbox`.
+ */
+export async function resolveGitUser(accountId: string): Promise<GitUser> {
+  const [accounts, emails] = await Promise.all([
+    selectAccounts(accountId),
+    selectAccountEmails({ accountIds: accountId }),
+  ]);
+
+  const account = accounts[0] ?? null;
+  const emailRow = emails.find(row => typeof row.email === "string" && row.email.length > 0);
+
+  const name = account?.name?.trim() || `recoupable-${accountId.slice(0, 8)}`;
+  const email = emailRow?.email ?? `${accountId}@users.noreply.recoupable.com`;
+
+  return { name, email };
+}