[damienrj]

Adds bl curl, a supported way for agents and scripts to call protected BuilderLab hosted apps. Today hosted apps only accept the browser-derived hosted-site session, so there's no supported way to curl them, and people copy browser cookies instead.

bl curl https://my-app.apps.block.builderlab.xyz/llms.txt
bl curl -X POST https://my-app.apps.block.builderlab.xyz/_compose/server/upload --data-binary @session.jsonl.gz

The first call for a tenant runs a type=cli_hosted browser login, which reuses the existing loopback, state and PKCE flow. It stores the resulting hosted-app session in the existing auth storage, separate from the normal CLI session, then runs the system curl with that session as the hosted-site cookie.

Security

• Only https://<app>.apps.<org>.<root> URLs for the configured org are accepted. Anything else is refused before any login or request. A session is stored only if the server's cookie_domain is exactly that tenant's hosted-app domain.
• The cookie and added headers are passed to curl on stdin with --config -, never on the command line. -q ignores ~/.curlrc, and --globoff keeps the URL to one request.
• Only an allowlist of curl options is accepted. Options that could print or forward the cookie are refused (-v, --trace*, --libcurl, -L, -b, -c, -K, -k, --resolve, -u, extra URLs), as are request bodies read from stdin. Negations that would undo an enforced option or hide the request method (--no-globoff, --no-disable, --no-get, --no-head) are refused too.
• POSTs to /_compose/server/* get Origin: https://<host> unless the user sets one.
• A 401 with X-BB-Consent-Url, or a {"error":"consent_required"} body, prints the approval URL and exits 3.
• A 401 with WWW-Authenticate: BBIdentity on a stored session drops it and logs in again. Only GET, HEAD and OPTIONS are resent automatically; other methods exit 3 and ask the user to rerun, so a mutation is never submitted twice.
• bl auth logout revokes each stored hosted session on the server (best effort), then removes it locally.

Depends on

A matching BuilderLab backend change that adds cli_hosted sessions to hosted-app ingress, and an ingress change that forwards the consent header on denials. Until those ship, bl curl gets the existing 401.

Open questions

• I assumed the hosted credential comes back in the existing session_credential field of the exchange response. The backend PR does it that way.
• cookie_domain must equal apps.<org>.<root>, ignoring a leading dot. A broader domain is refused.
• Hosted-app roots are a fixed list (builderlab.xyz, builderlabstaging.xyz). Other environments would need adding.

[nathan-thillairajah]

🤖 left three inline comments on mutation retries, hosted-session logout, and URL globbing.