diff --git a/README.md b/README.md
index d0ce55b..4de5adb 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,7 @@ Prometheus is a Slack bot that lets community members take responsibility for ke
 | `coin`                                               | Everyone      | Flip a coin                            |
 | `cat`                                                | Everyone      | Get a random cat fact                  |
 | `define <word>`                                      | Everyone      | Look up a word's definition            |
+| `github [owner/]repo`                                | Everyone      | Look up info about a GitHub repository |
 | `help`                                               | Everyone      | Show available commands                |
 | `here <message>`                                     | Moderators    | Ping all online members in the channel |
 | `channel <message>`                                  | Moderators    | Ping everyone in the channel           |
diff --git a/lib/commands/github.js b/lib/commands/github.js
new file mode 100644
index 0000000..7e2bceb
--- /dev/null
+++ b/lib/commands/github.js
@@ -0,0 +1,151 @@
+const FETCH_TIMEOUT_MS = 5000;
+const CACHE_TTL_MS = 5 * 60 * 1000;
+const DEFAULT_OWNER = "hackclub";
+const NAME_PART = /^(?!\.+$)[a-zA-Z0-9._-]+$/;
+
+const MSG_USAGE = ":red-x: Usage: `/pro github [owner/]repo`";
+const MSG_INVALID_NAME = ":red-x: That doesn't look like a valid owner/repo name.";
+const MSG_NOT_FOUND = (owner, repo) => `:red-x: Couldn't find \`${owner}/${repo}\` on GitHub.`;
+const MSG_RATE_LIMITED = ":red-x: Hit GitHub's rate limit — try again in a bit.";
+const MSG_ERROR = ":red-x: Couldn't reach GitHub. Try again in a bit.";
+
+const escapeMrkdwn = (text) =>
+  String(text).replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;");
+
+function parseRepoArg(raw) {
+  const parts = raw.split("/");
+  if (parts.length > 2 || parts.some((p) => !p || !NAME_PART.test(p))) return null;
+  if (parts.length === 2) return { owner: parts[0], repo: parts[1] };
+  return { owner: DEFAULT_OWNER, repo: parts[0] };
+}
+
+const cache = new Map();
+
+function getCached(key) {
+  const entry = cache.get(key);
+  return entry && entry.expiresAt > Date.now() ? entry.data : null;
+}
+
+function setCached(key, data) {
+  cache.set(key, { data, expiresAt: Date.now() + CACHE_TTL_MS });
+}
+
+async function fetchRepo(owner, repo) {
+  const key = `${owner}/${repo}`.toLowerCase();
+  const cached = getCached(key);
+  if (cached) return { data: cached };
+
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);
+
+  try {
+    const res = await fetch(`https://api.github.com/repos/${owner}/${repo}`, {
+      signal: controller.signal,
+      headers: { Accept: "application/vnd.github+json", "User-Agent": "prometheus-slack-bot" },
+    });
+
+    if (res.status === 404) return { notFound: true };
+    if (res.status === 403 && res.headers.get("x-ratelimit-remaining") === "0") {
+      return { rateLimited: true };
+    }
+    if (!res.ok) throw new Error(`GitHub API HTTP ${res.status}`);
+
+    const json = await res.json();
+    const data = {
+      fullName: json.full_name,
+      htmlUrl: json.html_url,
+      description: json.description,
+      stars: json.stargazers_count,
+      forks: json.forks_count,
+      language: json.language,
+      openIssues: json.open_issues_count,
+      license: json.license?.name,
+      pushedAt: json.pushed_at,
+      createdAt: json.created_at,
+      archived: json.archived,
+      homepage: json.homepage || null,
+      topics: json.topics || [],
+      isFork: json.fork,
+      parentFullName: json.parent?.full_name,
+      parentUrl: json.parent?.html_url,
+    };
+    setCached(key, data);
+    return { data };
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+function slackDate(iso, label) {
+  const ts = Math.floor(new Date(iso).getTime() / 1000);
+  return `${label} <!date^${ts}^{date_short_pretty}|${iso}>`;
+}
+
+function buildRepoBlocks(data) {
+  const lines = [
+    `:github: *<${data.htmlUrl}|${escapeMrkdwn(data.fullName)}>*${data.archived ? " _(archived)_" : ""}`,
+  ];
+
+  if (data.isFork && data.parentFullName) {
+    lines.push(`_Forked from <${data.parentUrl}|${escapeMrkdwn(data.parentFullName)}>_`);
+  }
+
+  if (data.description) lines.push(escapeMrkdwn(data.description));
+
+  if (data.homepage) lines.push(`:link: <${data.homepage}>`);
+
+  if (data.topics.length) {
+    lines.push(data.topics.map((t) => `\`${escapeMrkdwn(t)}\``).join(" "));
+  }
+
+  const stats = [`:star: ${data.stars.toLocaleString()}`, `:fork: ${data.forks.toLocaleString()}`];
+  if (data.language) stats.push(escapeMrkdwn(data.language));
+  stats.push(`${data.openIssues.toLocaleString()} open issues`);
+  if (data.license) stats.push(escapeMrkdwn(data.license));
+  lines.push(stats.join("  ·  "));
+
+  const dates = [];
+  if (data.createdAt) dates.push(slackDate(data.createdAt, "Created"));
+  if (data.pushedAt) dates.push(slackDate(data.pushedAt, "last pushed"));
+  if (dates.length) lines.push(dates.join(", "));
+
+  return [{ type: "section", text: { type: "mrkdwn", text: lines.join("\n") } }];
+}
+
+export default {
+  name: "github",
+  description: "Look up info about a GitHub repository",
+
+  async execute({ command: cmd, args, respond }) {
+    const err = (text) => respond({ response_type: "ephemeral", text });
+
+    const raw = args.join(" ").trim();
+    if (!raw) return err(MSG_USAGE);
+
+    const parsed = parseRepoArg(raw);
+    if (!parsed) return err(MSG_INVALID_NAME);
+
+    try {
+      const result = await fetchRepo(parsed.owner, parsed.repo);
+
+      if (result.notFound) {
+        console.log(`[github] ${cmd.user_id} not found: ${parsed.owner}/${parsed.repo}`);
+        return err(MSG_NOT_FOUND(parsed.owner, parsed.repo));
+      }
+      if (result.rateLimited) {
+        console.log(`[github] rate limited on ${parsed.owner}/${parsed.repo}`);
+        return err(MSG_RATE_LIMITED);
+      }
+
+      console.log(`[github] ${cmd.user_id} looked up ${parsed.owner}/${parsed.repo}`);
+      await respond({
+        response_type: "ephemeral",
+        text: result.data.fullName,
+        blocks: buildRepoBlocks(result.data),
+      });
+    } catch (e) {
+      console.log(`[github] error for ${parsed.owner}/${parsed.repo}: ${e.message}`);
+      return err(MSG_ERROR);
+    }
+  },
+};