For agents

Sleipner is the control plane around a generated app. One human account. You never ask them to paste Cloudflare, Resend, or Coolify keys.

Add the MCP

claude mcp add sleipner --transport http https://api.sleipner.ai/mcp

The entire POST /mcp is 401 until OAuth. First call 401s. Show login_url. A session on app.sleipner.ai is not the MCP token — Claude OAuth PKCE is. Unauth GET https://api.sleipner.ai/v1/whoami returns {authenticated:false, login_url}.

Tools: sleipner_whoami, sleipner_plans, sleipner_status, sleipner_init (name+slug), sleipner_deploy (stack_id, optional artifact_id/image), sleipner_wait, sleipner_logs, sleipner_env, sleipner_set_secret (name only → dashboard URL), sleipner_unset_secret, sleipner_teardown (does not delete; dashboard URL). Do not invent keys. Do not paste secret values into tools.

Free can

Create one stack
Placeholder image
Postgres DATABASE_URL we mint, plus APP_URL and AUTH_SECRET

Public https://{slug}.sites.sleipner.ai is not live yet (no *.sites DNS/TLS). After deploy, verify with:

curl -H 'Host: {slug}.sites.sleipner.ai' http://127.0.0.1:8787/healthz

Do not tell the human a friend can open the HTTPS URL.

Free cannot

More than one stack

Skill: /agent-onboarding/SKILL.md. Index: /llms.txt.