fix(modal): prefer the control-plane-minted clone_token over Modal-side resolution

api_create_sandbox + api_restore_sandbox computed clone_token = _resolve_clone_token()
(Modal-side: hardcoded GITHUB_CLONE_TOKEN env or generate_clone_token_from_env), which
overrode and discarded the clone_token the control plane sends in the request. The
worker is the authoritative credential resolver (it mints a repo-scoped GitHub App
installation token from the org's installation + per-tenant context), so its token was
silently dropped and private repos cloned UNAUTHENTICATED (sandbox: 'fatal: could not
read Username' -> with the clone-failure fix, a clear error). Now: clone_token =
request.get('clone_token') or _resolve_clone_token() (prefer worker, fall back to
Modal-side). Diagnostic: scripts/gh-app-info.ts (mint App JWT, list installs, test a
repo's clone token) — proved the App is installed on omoios/all and the token mints.

Author: kivo360

packages/modal-infra/src/web_api.py

@@ -150,7 +150,12 @@ async def api_create_sandbox(
 
         manager = SandboxManager()
 
-        clone_token = _resolve_clone_token()
+        # Prefer the control-plane-minted token: the worker is the authoritative
+        # credential resolver (it holds the GitHub App creds, the per-tenant context,
+        # and the entitlement decision, and mints a repo-scoped installation token).
+        # Fall back to Modal-side resolution (hardcoded PAT / env) only when the
+        # request omits one (e.g. older control planes).
+        clone_token = request.get("clone_token") or _resolve_clone_token()
 
         session_config = SessionConfig(
             session_id=request.get("session_id"),
@@ -489,7 +494,9 @@ async def api_restore_sandbox(
         timeout_seconds = int(request.get("timeout_seconds", DEFAULT_SANDBOX_TIMEOUT_SECONDS))
 
         manager = SandboxManager()
-        clone_token = _resolve_clone_token()
+        # Prefer the control-plane-minted token (see api_create_sandbox), else
+        # fall back to Modal-side resolution.
+        clone_token = request.get("clone_token") or _resolve_clone_token()
 
         code_server_enabled = bool(request.get("code_server_enabled", False))
         sandbox_settings = request.get("sandbox_settings") or None

scripts/gh-app-info.ts

@@ -0,0 +1,106 @@
+// Diagnostic: mint a GitHub App JWT from .dev.vars (GITHUB_APP_ID + GITHUB_APP_PRIVATE_KEY)
+// and report the App's install URL + every org/account it's currently installed on.
+// Read-only (GET /app, GET /app/installations). Run: npx tsx scripts/gh-app-info.ts
+import { readFileSync } from "node:fs";
+import { createSign } from "node:crypto";
+
+function fromDevVars(name: string): string {
+  const raw = readFileSync(".dev.vars", "utf8");
+  // Match KEY=value where value may be double-quoted and span multiple lines.
+  const quoted = new RegExp(`^\\s*${name}="([\\s\\S]*?)"\\s*$`, "m").exec(raw);
+  if (quoted) return quoted[1].replace(/\\n/g, "\n");
+  const bare = new RegExp(`^\\s*${name}=(.+)$`, "m").exec(raw);
+  if (bare) return bare[1].trim().replace(/^"|"$/g, "").replace(/\\n/g, "\n");
+  throw new Error(`${name} not found in .dev.vars`);
+}
+
+function b64url(buf: Buffer | string): string {
+  return Buffer.from(buf).toString("base64").replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
+}
+
+function appJwt(appId: string, pemRaw: string): string {
+  // .dev.vars stores the key with no line breaks (-----BEGIN-----<base64>-----END-----);
+  // the Worker decodes the raw DER, but Node's PEM parser needs wrapped lines. Re-wrap.
+  const body = pemRaw.replace(/-----(BEGIN|END) PRIVATE KEY-----/g, "").replace(/\s/g, "");
+  const pem = `-----BEGIN PRIVATE KEY-----\n${(body.match(/.{1,64}/g) ?? []).join("\n")}\n-----END PRIVATE KEY-----\n`;
+  const now = Math.floor(Date.now() / 1000);
+  const header = b64url(JSON.stringify({ alg: "RS256", typ: "JWT" }));
+  const payload = b64url(JSON.stringify({ iat: now - 60, exp: now + 540, iss: appId }));
+  const data = `${header}.${payload}`;
+  const sig = createSign("RSA-SHA256").update(data).end().sign(pem);
+  return `${data}.${b64url(sig)}`;
+}
+
+async function gh(path: string, jwt: string): Promise<unknown> {
+  const res = await fetch(`https://api.github.com${path}`, {
+    headers: {
+      Accept: "application/vnd.github+json",
+      Authorization: `Bearer ${jwt}`,
+      "X-GitHub-Api-Version": "2022-11-28",
+      "User-Agent": "agent-coordinator",
+    },
+  });
+  const body = await res.text();
+  if (!res.ok) throw new Error(`GET ${path} -> ${res.status} ${body.slice(0, 200)}`);
+  return JSON.parse(body);
+}
+
+async function main(): Promise<void> {
+  const appId = process.env.GITHUB_APP_ID ?? "3939828"; // wrangler.jsonc var, not a .dev.vars secret
+  const pem = fromDevVars("GITHUB_APP_PRIVATE_KEY");
+  const jwt = appJwt(appId, pem);
+
+  const app = (await gh("/app", jwt)) as { slug?: string; name?: string; html_url?: string };
+  console.log(`App: ${app.name} (slug=${app.slug}, id=${appId})`);
+  console.log(`Install URL: https://github.com/apps/${app.slug}/installations/new`);
+
+  const insts = (await gh("/app/installations", jwt)) as Array<{
+    id?: number;
+    account?: { login?: string; type?: string };
+    repository_selection?: string;
+  }>;
+  console.log(`\nCurrently installed on ${insts.length} account(s):`);
+  for (const i of insts) {
+    console.log(`  - ${i.account?.login} (${i.account?.type})  installation_id=${i.id}  repos=${i.repository_selection}`);
+  }
+  if (insts.length === 0) console.log("  (none — the App isn't installed anywhere yet)");
+
+  // Replicate resolveInstallationToken (src/lib/github-token-resolver.ts) for a repo,
+  // to confirm a clone token is obtainable: GET /repos/:o/:r/installation -> POST tokens.
+  const tokenRepo = process.env.TOKEN_REPO; // "owner/repo"
+  if (tokenRepo) {
+    const [owner, repo] = tokenRepo.split("/");
+    console.log(`\n=== Resolve clone token for ${owner}/${repo} (repo-based lookup) ===`);
+    try {
+      const inst = (await gh(`/repos/${owner}/${repo}/installation`, jwt)) as { id?: number };
+      console.log(`  lookup -> installation_id=${inst.id}`);
+      const res = await fetch(`https://api.github.com/app/installations/${inst.id}/access_tokens`, {
+        method: "POST",
+        headers: {
+          Accept: "application/vnd.github+json",
+          Authorization: `Bearer ${jwt}`,
+          "X-GitHub-Api-Version": "2022-11-28",
+          "User-Agent": "agent-coordinator",
+        },
+        body: JSON.stringify({
+          repositories: [repo],
+          permissions: { contents: "write", metadata: "read", pull_requests: "write", workflows: "write" },
+        }),
+      });
+      const body = await res.text();
+      if (res.ok) {
+        const tok = JSON.parse(body) as { token?: string; expires_at?: string };
+        console.log(`  TOKEN OBTAINED ✓  ${tok.token?.slice(0, 8)}…  expires ${tok.expires_at}`);
+      } else {
+        console.log(`  TOKEN FAILED ✗  ${res.status} ${body.slice(0, 200)}`);
+      }
+    } catch (e) {
+      console.log(`  LOOKUP FAILED ✗  ${e instanceof Error ? e.message : e}`);
+    }
+  }
+}
+
+main().catch((e) => {
+  console.error("gh-app-info failed:", e instanceof Error ? e.message : e);
+  process.exit(1);
+});