Documentation
littlebook computes, for a birth date, the natal cards and the card of each cycle (life: 13 years, seven years: 1 year, 52-day period, day), at any date between the birth and the 120th birthday. Profiles are not stored: each call sends them.
MCP connector (Claude, ChatGPT)
Connector URL: https://api.littlebook.cards/mcp
- claude.ai, ChatGPT: add a custom connector with this URL. The application sends you here to sign in and allow access (OAuth).
- Claude Code, with your API key:
claude mcp add --transport http littlebook https://api.littlebook.cards/mcp \ --header "Authorization: Bearer YOUR_KEY"
Tools: get_profile, get_cycle_cards, get_timeline, find_card_dates, get_spread, get_card_in_tableau, compare_profiles. Give the birth date and, if you can, the birth time and timezone: without them, the ruling cards may be ambiguous.
REST API
Authentication: Authorization: Bearer YOUR_KEY (key on your account). Profiles travel in the JSON body of POST requests, never in the URL.
curl -s https://api.littlebook.cards/v1/cycles -H "Authorization: Bearer YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"profile": {"birthdate": "1990-05-17", "birthtime": "08:15", "tz": "Asia/Tokyo"}, "date": "2026-01-01"}'
| Call | Purpose |
|---|---|
POST /v1/profile | natal cards, rulers, suits |
POST /v1/cycles | the card of each cycle at a date |
POST /v1/timeline | the cards of a cycle over a period |
POST /v1/search/card-dates | when a card comes back in a cycle |
POST /v1/spreads/current | the tableau of a cycle at a date |
POST /v1/relation | the cards two profiles share |
GET /v1/spreads/{index}/cards/{card_id} | a card in a tableau: place, environment and displacement cards |
GET /v1/spreads/{index}, GET /v1/cards | tableaux and cards |
Full reference: Swagger (OpenAPI). Every error has the shape {"error", "message", "details"}. Limit: 10 requests per second per key, bursts of 30.