diff --git a/server/create-content.mjs b/server/create-content.mjs
index 586f664..dbf6a71 100644
--- a/server/create-content.mjs
+++ b/server/create-content.mjs
@@ -15,6 +15,7 @@ import { mkdirSync, writeFileSync, existsSync } from "node:fs";
 import { join, dirname } from "node:path";
 import { execFileSync } from "node:child_process";
 import { descriptorById } from "./content-types.mjs";
+import { ANGLESITE_COMMIT_IDENTITY } from "./git-identity.mjs";
 
 /**
  * Scaffold a new Astro page under `src/pages/`.
@@ -215,14 +216,24 @@ function renderEntry(descriptor, title, now = new Date()) {
  * Stage and commit exactly `relPath` on the current branch. Returns the new HEAD SHA, or null
  * on any failure (not a git repo, no prior commit, a pre-commit hook rejecting, git missing).
  * Commits a single pathspec so unrelated staged/working changes are left untouched.
+ *
+ * Passes `ANGLESITE_COMMIT_IDENTITY` on the commit itself: guest environments (e.g. the
+ * Anglesite-app container) have no `user.name`/`user.email` git config, and `git commit`'s
+ * own auto-detect fallback ("Please tell me who you are") fails there too — same root cause
+ * as #428, see `git-identity.mjs`.
  */
 function commitFile(projectRoot, relPath, message) {
-  const run = (args) =>
-    execFileSync("git", args, { cwd: projectRoot, encoding: "utf-8", stdio: ["ignore", "pipe", "pipe"] }).trim();
+  const run = (args, env = {}) =>
+    execFileSync("git", args, {
+      cwd: projectRoot,
+      encoding: "utf-8",
+      stdio: ["ignore", "pipe", "pipe"],
+      env: { ...process.env, ...env },
+    }).trim();
   try {
     run(["rev-parse", "--git-dir"]);
     run(["add", "--", relPath]);
-    run(["commit", "-m", message, "--", relPath]);
+    run(["commit", "-m", message, "--", relPath], ANGLESITE_COMMIT_IDENTITY);
     return run(["rev-parse", "HEAD"]);
   } catch {
     return null;
diff --git a/test/create-content.test.js b/test/create-content.test.js
index 64be772..b79bf53 100644
--- a/test/create-content.test.js
+++ b/test/create-content.test.js
@@ -212,3 +212,50 @@ describe("createTyped", () => {
     }
   });
 });
+
+describe("commitFile — no ambient git identity (#428)", () => {
+  // Reproduces the container guest environment from #428: no ~/.gitconfig, no
+  // GIT_AUTHOR/COMMITTER_NAME/EMAIL in the ambient environment. `git commit`'s own
+  // auto-detect fallback fails there too ("Please tell me who you are"), same as
+  // commit-tree — createPage/createPost/createTyped must supply their own identity
+  // rather than relying on it (see git-identity.mjs).
+  const identityKeys = [
+    "GIT_AUTHOR_NAME", "GIT_AUTHOR_EMAIL", "GIT_COMMITTER_NAME", "GIT_COMMITTER_EMAIL",
+    "GIT_CONFIG_GLOBAL", "GIT_CONFIG_SYSTEM", "GIT_CONFIG_NOSYSTEM",
+  ];
+  let saved;
+
+  beforeEach(() => {
+    git(["config", "--unset", "user.email"]);
+    git(["config", "--unset", "user.name"]);
+    // Also isolate from this sandbox's own ~/.gitconfig and any system config, so the
+    // ambient environment matches the container guest in #428: no identity available
+    // from config OR env, anywhere.
+    saved = Object.fromEntries(identityKeys.map((k) => [k, process.env[k]]));
+    identityKeys.forEach((k) => delete process.env[k]);
+    process.env.GIT_CONFIG_GLOBAL = "/dev/null";
+    process.env.GIT_CONFIG_NOSYSTEM = "1";
+  });
+
+  afterEach(() => {
+    identityKeys.forEach((k) => {
+      if (saved[k] === undefined) delete process.env[k];
+      else process.env[k] = saved[k];
+    });
+  });
+
+  it("createPage still commits", () => {
+    const result = createPage(repo, { name: "About Us" });
+    expect(result.commit).toMatch(/^[0-9a-f]{40}$/);
+  });
+
+  it("createPost still commits", () => {
+    const result = createPost(repo, { title: "Hello, World!" });
+    expect(result.commit).toMatch(/^[0-9a-f]{40}$/);
+  });
+
+  it("createTyped still commits", () => {
+    const result = createTyped(repo, { type: "note", title: "Quick thought" });
+    expect(result.commit).toMatch(/^[0-9a-f]{40}$/);
+  });
+});