Astro — Multi-Tradition Astrology Engine for AI Agents

Trustworthy birth charts, transits, and synastry across Western, Vedic/Jyotish, and Chinese BaZi. The engine computes; the model interprets.

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Paste this into any AI chat or agent (Claude, ChatGPT, Gemini, Claude Code, Cursor, Codex, DeepSeek, Perplexity…). It installs Astro itself — you don't set anything up first:

You are my personal astrologer powered by Astro, an open-source multi-tradition astrology engine that computes mathematically real charts instead of guessing: https://github.com/aryaminus/astro

SET YOURSELF UP now using whatever you're capable of — try in this order, don't ask me first:
1. If you can run shell/terminal commands, get the pure-Python engine (zero dependencies — no pip install) by ANY of these:
   - `git clone https://github.com/aryaminus/astro` — most reliable; engine at astro/skills/astrology/scripts/astro_engine.py
   - `npx skills add aryaminus/astro -g` — installs the skill on Claude Code, Cursor, Codex, Gemini CLI + 50+ hosts (engine at skills/astrology/scripts/astro_engine.py)
   - latest packaged release (needs only curl + unzip): `curl -L -o astrology.skill https://github.com/aryaminus/astro/releases/latest/download/astrology.skill && unzip astrology.skill` — engine then at scripts/astro_engine.py
   Then run it: `python3 <path>/astro_engine.py --json '{"year":1990,"month":6,"day":15,"hour":14,"minute":30,"lat":40.7128,"lng":-74.0060,"tz":"America/New_York"}'`. Required: year, month, day, lat, lng (decimals, East +/West −), tz (IANA name like "America/New_York"); optional: hour+minute (omit → Sun-sign level), name, gender, "mode" (transit / synastry / compatibility / solar_return / …), "systems":["western","vedic","bazi"]. Look up the user's city's lat/lng/tz yourself.
2. If you already have an Astro MCP server or REST API connected, use those tools to compute charts. Public MCP SSE endpoint: `https://astro-api-a2rc.onrender.com/mcp/sse` (~30s cold start after idle).
3. If you can only browse the web: read the canonical spec and follow it as your operating instructions — https://raw.githubusercontent.com/aryaminus/astro/main/skills/astrology/SKILL.md — and fetch the classical reference rulesets it links (western, vedic, bazi, synastry-and-timing, consultation) from https://github.com/aryaminus/astro/tree/main/skills/astrology/references
4. If you can't do any of the above: tell me in one line how to install it (`npx skills add aryaminus/astro -g`, or download the skill from https://github.com/aryaminus/astro/releases/latest for claude.ai), then proceed by interpreting from classical reference and state clearly that you are NOT computing real positions.

THEN behave exactly as Astro's SKILL.md defines:
- COMPUTE the real chart before interpreting — NEVER invent a planetary position, house, or aspect. If no compute path worked, say so honestly.
- CITE specific placements ("your Moon in Pisces in the 4th house"); never generic statements true of everyone.
- ROUTE by question: love → synastry/compatibility; timing/career → transits; year ahead → solar return + progressions; where to live → astrocartography; auspicious dates → electional + panchang.
- TRADITIONS: Western tropical by default; Vedic (dasha/nakshatra) when I ask; Chinese BaZi (four pillars) when I ask.
- ETHICS: never predict death or guaranteed doom; give me agency; if I'm in crisis, point me to real emergency help first.

Now ask me for my birth details (date — and ideally exact time + city) and let's begin.

Local install — works on Claude Code, Cursor, Codex, Copilot, Gemini CLI, and 50+ Agent Skills hosts:

npx skills add aryaminus/astro -g

Host	Install	Update
Claude Code	/plugin marketplace add aryaminus/astro then /plugin install astrology	Auto via marketplace
Codex, Cursor, Copilot, Gemini CLI, 50+ hosts	npx skills add aryaminus/astro -g	npx skills update astrology -g
claude.ai	Download .skill → Customize → Skills → +	Re-download
ChatGPT	Copy openapi.yaml into Custom GPT → Actions → Import	Manual
Poke (Messages/WhatsApp/Telegram)	Add as MCP integration → URL: https://astro-api-a2rc.onrender.com/mcp/sse	—
Claude Desktop / Zed	npx @smithery/cli install astrology --client claude	Re-run
Manual / dev	git clone https://github.com/aryaminus/astro.git && ln -sfn "$(pwd)/astro/skills/astrology" ~/.agents/skills/astrology	git pull

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Why this exists

A raw LLM cannot tell you where Mars was on a Tuesday in 1997 — it hallucinates chart data. Astro splits the work:

1. Engine — deterministic Python math computes real sky positions (zero deps, pure stdlib)
2. Skill — orchestrates the engine + loads classical interpretation rulesets
3. Glue — MCP, REST, CLI, ChatGPT Actions reach the engine from any platform

The model never guesses a position. It interprets structured output grounded in 8 classical rulesets.

19 modes · 3 traditions · zero dependencies

Modes: natal, transit, synastry, compatibility, composite, astrocartography, horary, event, solar/lunar/planetary return, navamsa, varga (D2–D60), panchang, moon phase, numerology, progressions, planetary hours, transit-to-natal aspects. Full list and parameters in skills/astrology/SKILL.md.

Traditions: Western tropical, Vedic/Jyotisha (Lahiri sidereal), Chinese BaZi + Tibetan/Buddhist.

Auto-included in every natal chart: Aspect patterns (Grand Trine, Kite, T-Square, Grand Cross, Yod, Mystic Rectangle, Stellium) · Part of Fortune · Vertex · Black Moon Lilith · Moon phase · 10 Arabic Parts · 23 fixed-star conjunctions · Navamsa D9 · Panchang · Mangal Dosha · Kaalsarpa Dosha.

Try it

After installing, ask any of these:

• "What's my chart?" → full natal
• "Am I compatible with…?" → synastry + 0–100 scoring
• "When's my Saturn return?" → planetary return + timing
• "Where should I live for career?" → astrocartography
• "What time should I start the meeting?" → Chaldean planetary hours
• "Pick an auspicious wedding date" → electional + panchang
• "Should I have surgery this month?" → medical timing
• "What does today have in store?" → transits + natal aspects

Project layout

astro/
├── skills/astrology/
│   ├── SKILL.md                    # runtime spec the model reads
│   ├── scripts/astro_engine.py     # deterministic engine (~2930 lines)
│   ├── scripts/mcp_server.py       # MCP wrapper (18 tools, stdio + SSE)
│   ├── scripts/api.py              # REST API (31 endpoints)
│   └── references/                 # 8 classical rulesets
│       ├── western.md · vedic.md · bazi.md · tibetan.md
│       ├── health.md · synastry-and-timing.md
│       ├── specialty-systems.md · consultation.md
├── openapi.yaml                    # OpenAPI 3.1 (ChatGPT, Agentforce, Coze)
├── smithery.yaml                   # Smithery registry
├── Dockerfile · docker-compose.yml · render.yaml   # cloud deploy
└── AGENTS.md · CONTRIBUTING.md · SECURITY.md · CHANGELOG.md

Cloud hosting

Free by default. No auth, no rate limits. Set ASTRO_API_KEY to gate, ASTRO_RATE_LIMIT to throttle.

Render (one-click, free tier): Connect this repo → New → Blueprint. render.yaml provisions everything. Verify with curl https://astro-api-a2rc.onrender.com/health. Free tier spins down after 15 min idle; first request after idle takes ~30s.

Docker:

docker compose up --build    # API on :8000, docs at /docs

Raw Python:

pip install -r requirements.txt
uvicorn skills.astrology.scripts.api:app --host 0.0.0.0 --port 8000

MCP SSE (Smithery, Cloudflare, Poke):

ASTRO_MCP_TRANSPORT=sse python -m skills.astrology.scripts.mcp_server

Cloud MCP SSE (no deploy needed): https://astro-api-a2rc.onrender.com/mcp/sse — free Render instance. ~30s cold start.

Env vars and operational endpoints documented in AGENTS.md.

Documentation

File	What it covers
AGENTS.md	Install methods, env vars, cloud config, MCP tools list
docs/cloud-setup.md	Using Astro on any AI chat (Claude, ChatGPT, Gemini, DeepSeek, Qwen)
skills/astrology/SKILL.md	Runtime spec, mode parameters, trust discipline
skills/astrology/README.md	Engine internals, API surface, specialty branches
openapi.yaml	REST API schema (ChatGPT, Agentforce, Coze)
CHANGELOG.md	Release history
CONTRIBUTING.md	Hard rules, dev workflow, PR checklist
SECURITY.md	Vulnerability reporting

Contributing

PRs welcome. Hard rules: engine stays zero-dep, engine never imports frameworks, touch all 4 surfaces (engine + MCP + REST + OpenAPI), the skill is honest. See CONTRIBUTING.md.

License

MIT. Reference texts in skills/astrology/references/ are original MIT-licensed syntheses of classical sources.