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Astro Agents Western Synastry API
x402
Astro Agents Western Synastry API is a paid API for AI agents from astro-agents-api.vercel.app, paid per call via x402, $0.12/call, status unknown (last checked 2026-10-12).
Computes deterministic Western astrological synastry (compatibility) between two people using the NASA/JPL DE440 ephemeris, returning cross-aspects, orbs, and aspect counts.
Price / call$0.12
Success—
StatusUnknown
How this service works
Deterministic Western + Vedic astrology API for AI agents: JPL DE440 ephemeris, no LLM, reproducible SHA-256 hashes.
Output
Returns a JSON object containing cross-aspects between the two charts (each with aspect type, angle, orb, orb allowed, and exactness percentage), summary counts of harmonious, challenging, and conjunction aspects, plus metadata including ephemeris source, engine version, determinism flag, and a SHA-256 hash of the result for reproducibility verification.
Example use cases
Romantic compatibility for a couple
“My partner and I want to know our astrological compatibility — she was born on April 3, 1992 at 7:15am in Paris (48.85°N, 2.35°E) and I was born on September 14, 1989 at 3:00pm in Chicago (41.88°N, 87.63°W). Can you run a Western synastry with Placidus houses and tropical zodiac and tell me our key cross-aspects?”
Business partner chart compatibility
“I'm considering a business partnership and want to check our synastry — Person A was born January 10, 1985 at 9:00am in Tokyo (35.68°N, 139.69°E) and Person B on July 25, 1980 at 2:30pm in Sydney (33.87°S, 151.21°E). Use whole sign houses and tropical zodiac, and focus on conjunction, opposition, and trine aspects only.”
Friendship compatibility check
“Can you check the astrological synastry between me and my best friend? I was born on November 1, 1995 at 6:00am in Berlin (52.52°N, 13.41°E) and she was born on February 14, 1996 at 10:00pm in Madrid (40.42°N, 3.70°W). Use Placidus houses and tropical zodiac — I want to see if we have more harmonious or challenging aspects.”
Technical details
Endpoint
POSThttps://astro-agents-api.vercel.app/v1/western/synastry?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need deterministic, reproducible astrological synastry calculations between two individuals using the NASA/JPL DE440 ephemeris with no LLM involvement — ideal for applications requiring auditable, hash-verifiable results. Prefer this over LLM-based astrology responses when precision, reproducibility, and Western tropical or sidereal methodology matter. Use when you need structured aspect data (orbs, exactness percentages, aspect types) rather than narrative interpretations.
Side effects
- Missing required latitude/longitude for either person returns validation error
- Invalid or out-of-range date/time values cause parsing failure
- Unsupported house system or ayanamsa enum value returns schema validation error
- Orb values exceeding maximum of 15 degrees are rejected
- Ambiguous local time without timezone or time_basis may yield incorrect planetary positions
- Dates outside ephemeris range (1800–2200) will fail
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"meta": {
"engine": "astro-agents/1.0.0",
"llm_used": false,
"ephemeris": "NASA/JPL DE440 (1800-01-01..2200-01-01)",
"deterministic": true,
"result_sha256": "d73954df219854b1f2ad98476b58986d82ee19cfffc91b8adaea011df6eb4f01"
},
"endpoint": "western/synastry",
"result_excerpt": {
"aspect_counts": {
"harmonious": 27,
"challenging": 28,
"conjunctions": 11
},
"cross_aspects": [
{
"orb": 0.192882,
"angle": 180,
"aspect": "opposition",
"point_a": "a:true_node",
"point_b": "b:mercury",
"orb_allowed": 8,
"exactness_pct": 97.6
}
]
}
}
}Tags
x402
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