Western Aspects
asterwise_get_western_aspects
Calculates all active aspects between a supplied set of planetary longitudes. Accepts a dictionary of body name to tropical ecliptic longitude and returns every aspect within standard natal orbs.
Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
positions | object | yes | |
response_format | enum: markdown, json | no |
What it covers
Flexible aspect calculator that works with any set of positions — natal planets, transit planets, progressed planets, or custom hypothetical points. Aspect orbs: conjunction/opposition 5°, square/trine 5°, sextile 3°, semisextile/quincunx/semisquare/sesquiquadrate 1.5°. Returns is_applying based on relative speeds if speeds are provided, otherwise assumed separating.
Workflow
BEFORE: None — standalone; or use asterwise_get_western_natal to get positions first.
AFTER: None.
Input
positions — dict mapping planet/body name (string) to tropical longitude (float 0–360).
Must contain at least 2 entries.
Example: {'Sun': 229.6, 'Moon': 221.8, 'Mars': 189.6, 'Jupiter': 309.6}
Names can be any string — the tool does not enforce planet names.
Output contract
data.aspects[] — each:
planet_a (string), planet_b (string), type (string — aspect name)
exact_angle (float), orb (float), is_applying (bool)
data.orbs_used — dict of aspect type to orb value used
data.body_count (int — number of input bodies)
data.aspect_count (int — number of aspects found)
Response format
response_format=json — aspect grid object.
response_format=markdown — formatted aspect table.
Compute class
FAST_LOOKUP
Errors
INVALID_PARAMS (local):
— fewer than 2 bodies in positions dict → MCP INVALID_PARAMS immediately.
INTERNAL_ERROR: Any upstream API failure → MCP INTERNAL_ERROR
Do not confuse with
asterwise_get_western_natal — computes both positions and aspects from birth data.
asterwise_get_western_synastry — inter-chart aspects between two people.
Connect
Remote MCP endpoint: https://mcp.asterwise.com/mcp. Authenticate with Authorization: Bearer <API key> or OAuth. See the MCP setup guide.