---
title: "Western Zodiac Sign Compatibility"
method: GET
path: "/v1/western/compatibility/zodiac"
tags: ["Western Astrology"]
---

# Western Zodiac Sign Compatibility

`GET /v1/western/compatibility/zodiac`

## Request

- Base URL: `https://api.asterwise.com`
- URL: `https://api.asterwise.com/v1/western/compatibility/zodiac`
- Auth: HTTP bearer

Sign-to-sign compatibility without birth data. Based on element and modality affinity (Asterwise heuristic scores). Pass sign names as query parameters: ?sign1=Aries&sign2=Leo. Only the twelve English tropical sign names are accepted (case-insensitive); anything else returns 422.

## Query parameters

- `sign1` string, required: First sign: an English tropical sign name such as Aries (case-insensitive).
- `sign2` string, required: Second sign: an English tropical sign name such as Leo (case-insensitive).

## Response `200`

Successful Response

- ApiResponseZodiacCompatibilityResponse
  - `success` boolean: True if the request succeeded
  - `message` string: Human-readable status message
  - `data` ZodiacCompatibilityResponse, required
    - `sign1` string, required
    - `sign2` string, required
    - `element1` string, required
    - `element2` string, required
    - `modality1` string, required
    - `modality2` string, required
    - `element_affinity` string, required: harmonious | neutral | challenging. From an Asterwise heuristic score: same element 80, fire–air and earth–water 85, other pairs 40–50 (harmonious ≥ 78, neutral ≥ 55).
    - `modality_affinity` string, required: harmonious | neutral | challenging. From an Asterwise heuristic score (cardinal–mutable 75, fixed–mutable 70, mutable–mutable 65, cardinal–cardinal and fixed–fixed 55, cardinal–fixed 50; harmonious ≥ 78, neutral ≥ 55).
    - `overall_score` integer, required: Mean of the element and modality heuristic scores (0–100)
    - `description` string, required

## Other responses

- `401`: Authentication failed
- `403`: Authorization failed
- `404`: Resource not found
- `413`: Payload too large
- `422`: Validation error
- `429`: Rate limit exceeded
- `500`: Internal error
- `502`: Upstream provider error
- `503`: Service unavailable

---

[API](https://skmtc.dev/asterwise/apis/asterwise-api.md) · [All operations](https://skmtc.dev/asterwise/apis/asterwise-api/llms.txt) · [OpenAPI document](https://skmtc.dev/asterwise/apis/asterwise-api/revisions/3c4bbb1194e2?raw)