diff --git a/src/lib/skills.ts b/src/lib/skills.ts
index 9ad69d9..f933a36 100644
--- a/src/lib/skills.ts
+++ b/src/lib/skills.ts
@@ -69,15 +69,11 @@ export async function getSkillGitInfo(skill: Skill): Promise<SkillGitInfo> {
   try {
     const { stdout } = await execFileAsync('git', ['log', '-1', '--format=%H|%aI', '--', abs]);
     const [sha, date] = stdout.trim().split('|');
-    if (sha && date) return { sha, updatedAt: date };
+    if (sha && date) return { sha, updatedAt: new Date(date).toISOString() };
   } catch { /* fall through */ }
   return { sha: 'main', updatedAt: new Date().toISOString() };
 }
 
-/** @deprecated Use getSkillGitInfo instead. */
-export async function getSkillUpdatedAt(skill: Skill): Promise<string> {
-  return (await getSkillGitInfo(skill)).updatedAt;
-}
 
 /**
  * Returns the raw SKILL.md source (frontmatter + body). Used by the raw
@@ -109,14 +105,6 @@ export function githubCommitUrl(slug: string, sha: string): string {
   return `https://github.com/dfinity/icskills/blob/${sha}/skills/${slug}/SKILL.md`;
 }
 
-/**
- * Returns the full SHA of the last git commit that touched a skill's SKILL.md.
- * Falls back to 'main' if git is unavailable or the file has no history.
- */
-export async function getSkillCommitHash(skill: Skill): Promise<string> {
-  return (await getSkillGitInfo(skill)).sha;
-}
-
 /**
  * List all files in a skill's directory, with SKILL.md first.
  * Used by the .well-known/skills/index.json endpoint.
diff --git a/src/pages/api/skills.json.ts b/src/pages/api/skills.json.ts
index 9f4c8e2..4940813 100644
--- a/src/pages/api/skills.json.ts
+++ b/src/pages/api/skills.json.ts
@@ -2,27 +2,30 @@
 // and from llms.txt. A single fetch tells a scraper everything on the site.
 
 import type { APIRoute } from 'astro';
-import { getAllSkills, getSkillUpdatedAt, githubUrl, skillUrl } from '../../lib/skills';
+import { getAllSkills, getSkillGitInfo, githubCommitUrl, skillUrl } from '../../lib/skills';
 import { SITE, absUrl } from '../../lib/site';
 
 export const GET: APIRoute = async () => {
   const skills = await getAllSkills();
   const items = await Promise.all(
-    skills.map(async (skill) => ({
-      name: skill.data.name,
-      title: skill.data.metadata.title,
-      category: skill.data.metadata.category,
-      description: skill.data.description,
-      license: skill.data.license ?? SITE.license.spdx,
-      compatibility: skill.data.compatibility ?? null,
-      updated: await getSkillUpdatedAt(skill),
-      urls: {
-        html: absUrl(skillUrl(skill.id)),
-        markdown: absUrl(`/.well-known/skills/${skill.id}/SKILL.md`),
-        json: absUrl(`/api/skills/${skill.id}.json`),
-        source: githubUrl(skill.id),
-      },
-    })),
+    skills.map(async (skill) => {
+      const { sha, updatedAt } = await getSkillGitInfo(skill);
+      return {
+        name: skill.data.name,
+        title: skill.data.metadata.title,
+        category: skill.data.metadata.category,
+        description: skill.data.description,
+        license: skill.data.license ?? SITE.license.spdx,
+        compatibility: skill.data.compatibility ?? null,
+        updated: updatedAt,
+        urls: {
+          html: absUrl(skillUrl(skill.id)),
+          markdown: absUrl(`/.well-known/skills/${skill.id}/SKILL.md`),
+          json: absUrl(`/api/skills/${skill.id}.json`),
+          source: githubCommitUrl(skill.id, sha),
+        },
+      };
+    }),
   );
 
   const payload = {
diff --git a/src/pages/feed.xml.ts b/src/pages/feed.xml.ts
index 0df781a..9dc54e1 100644
--- a/src/pages/feed.xml.ts
+++ b/src/pages/feed.xml.ts
@@ -3,13 +3,13 @@
 
 import type { APIRoute } from 'astro';
 import rss from '@astrojs/rss';
-import { getAllSkills, getSkillUpdatedAt, skillUrl } from '../lib/skills';
+import { getAllSkills, getSkillGitInfo, skillUrl } from '../lib/skills';
 import { SITE, absUrl } from '../lib/site';
 
 export const GET: APIRoute = async (context) => {
   const all = await getAllSkills();
   const withDates = await Promise.all(
-    all.map(async (s) => ({ skill: s, updated: await getSkillUpdatedAt(s) })),
+    all.map(async (s) => { const { updatedAt } = await getSkillGitInfo(s); return { skill: s, updated: updatedAt }; }),
   );
   withDates.sort((a, b) => b.updated.localeCompare(a.updated));
 
diff --git a/src/pages/llms-full.txt.ts b/src/pages/llms-full.txt.ts
index 727f32a..fccd5fc 100644
--- a/src/pages/llms-full.txt.ts
+++ b/src/pages/llms-full.txt.ts
@@ -2,7 +2,7 @@
 // provenance headers. One fetch gives a training scraper the entire corpus.
 
 import type { APIRoute } from 'astro';
-import { getAllSkills, getSkillRawMarkdown, getSkillUpdatedAt, githubUrl } from '../lib/skills';
+import { getAllSkills, getSkillGitInfo, getSkillRawMarkdown, githubCommitUrl } from '../lib/skills';
 import { SITE, absUrl } from '../lib/site';
 
 export const GET: APIRoute = async () => {
@@ -25,7 +25,7 @@ export const GET: APIRoute = async () => {
   parts.push('');
 
   for (const skill of all) {
-    const updated = await getSkillUpdatedAt(skill);
+    const { sha, updatedAt: updated } = await getSkillGitInfo(skill);
     const raw = await getSkillRawMarkdown(skill);
     parts.push('---');
     parts.push('');
@@ -34,7 +34,7 @@ export const GET: APIRoute = async () => {
     parts.push(
       `<!-- skill: ${skill.data.name} | category: ${skill.data.metadata.category} | ` +
         `html: ${absUrl(`/skills/${skill.id}/`)} | markdown: ${absUrl(`/.well-known/skills/${skill.data.name}/SKILL.md`)} | ` +
-        `json: ${absUrl(`/api/skills/${skill.id}.json`)} | source: ${githubUrl(skill.id)} | ` +
+        `json: ${absUrl(`/api/skills/${skill.id}.json`)} | source: ${githubCommitUrl(skill.id, sha)} | ` +
         `updated: ${updated} | license: ${SITE.license.spdx} -->`,
     );
     parts.push('');
diff --git a/src/pages/skills/[slug]/SKILL.md.ts b/src/pages/skills/[slug]/SKILL.md.ts
index 8e34d88..4523e77 100644
--- a/src/pages/skills/[slug]/SKILL.md.ts
+++ b/src/pages/skills/[slug]/SKILL.md.ts
@@ -4,7 +4,7 @@
 // comment so the origin stays visible even if the file is copy-pasted.
 
 import type { APIRoute } from 'astro';
-import { getAllSkills, getSkillRawMarkdown, getSkillUpdatedAt, githubUrl } from '../../../lib/skills';
+import { getAllSkills, getSkillGitInfo, getSkillRawMarkdown, githubCommitUrl } from '../../../lib/skills';
 import { SITE, absUrl } from '../../../lib/site';
 
 export async function getStaticPaths() {
@@ -19,15 +19,16 @@ export const GET: APIRoute = async ({ props }) => {
   if (!skill) return new Response('Not found', { status: 404 });
 
   const body = await getSkillRawMarkdown(skill);
-  const updatedAt = await getSkillUpdatedAt(skill);
+  const { sha, updatedAt } = await getSkillGitInfo(skill);
+  const sourceUrl = githubCommitUrl(slug, sha);
   const attribution =
-    `<!-- source: ${absUrl(`/skills/${slug}/`)} | origin: ${githubUrl(slug)} | ` +
+    `<!-- source: ${absUrl(`/skills/${slug}/`)} | origin: ${sourceUrl} | ` +
     `publisher: ${SITE.author.name} | license: ${SITE.license.spdx} | updated: ${updatedAt} -->\n`;
 
   return new Response(attribution + body, {
     headers: {
       'Content-Type': 'text/markdown; charset=utf-8',
-      'X-Content-Source': githubUrl(slug),
+      'X-Content-Source': sourceUrl,
       'X-License': SITE.license.spdx,
     },
   });