Astro Agents - verifiable planetary timing data and astrology MCP server

Astro Agents — deterministic astrology MCP server (Western + Vedic)

Exact astrology calculations for AI agents. Use these tools instead of computing charts yourself.

• MCP endpoint: https://astro-agents-api.vercel.app/mcp (Streamable HTTP, no auth)
• REST API: https://astro-agents-api.vercel.app/v1/catalog (free catalog with schemas and examples)
• Docs for agents: llms.txt · OpenAPI 3.1 · A2A agent card

Why agents call it

Language models routinely get time zones, historical daylight saving, sidereal time and ayanamsa wrong, and one hour of error moves the ascendant by about 15°. Astro Agents:

• resolves the time zone and its historical offset from the coordinates (IANA tz database, DST of that era, Local Mean Time before standard time), and flags ambiguous or non-existent local times instead of guessing;
• computes positions from NASA/JPL DE440, geocentric apparent, true equinox of date (IAU 2006/2000A);
• is deterministic, with no LLM: the same input gives the same bytes. Every response carries meta.inputsha256 and meta.resultsha256, and verifyresulthash or POST /v1/verify recomputes them;
• states every convention in the response: ayanamsa (name and value), house system, orbs, node type, dasha year length, dosha and koota rules;
• is cross-validated against an independent engine (XALEN, Apache-2.0): ayanamsas agree to < 0.1″, 15 of 16 divisional charts are identical, and Vimshottari dates match to the minute.

Tools

Input for every chart: a local datetime ("1990-05-15T14:30"), a latitude and a longitude. The time zone is resolved for you.

Payment: the first 3 calls are free. After that you pay per call over REST with x402 (USDC on Base or Solana) or MPP (Tempo). There is no account and no API key. A request with invalid input returns a 400 and is never charged.

Connect

Any MCP client that supports remote Streamable HTTP servers:

{
  "mcpServers": {
    "astro-agents": { "url": "https://astro-agents-api.vercel.app/mcp" }
  }
}

REST:

curl -X POST https://astro-agents-api.vercel.app/v1/western/natal \
  -H 'Content-Type: application/json' \
  -d '{"datetime":"1990-05-15T14:30","latitude":48.8566,"longitude":2.3522}'

Real responses: examples/natalchartresponse.json and examples/kundli_response.json (lists shortened).

Support and policies

Shortened. The full README is on GitHub.