> ## Documentation Index
> Fetch the complete documentation index at: https://docs.geometry.app/llms.txt
> Use this file to discover all available pages before exploring further.

# get_compatibility

> Two birth dates → structured compatibility score (Tool 1).

# get\_compatibility

Two birth dates in → both identities, connections between them, and a scored breakdown. Scoring follows cardology canon (Robert Camp connection system) — fixed weights, transparent, never tuned to fit outcomes.

|             |                                                               |
| ----------- | ------------------------------------------------------------- |
| **Input**   | `birth_date_a`, `birth_date_b` (YYYY-MM-DD)                   |
| **Range**   | Same published window as Tool 2 — `1900-01-01` … `2100-12-31` |
| **MCP URL** | `https://mcp.geometry.app/mcp`                                |

**Ask:**

> How compatible are people born 1985-03-15 and 1990-11-08?

Live payloads are large (\~85 KB) because each side embeds a full cosmic block. Below is a teaching excerpt — `birth_card_a` / `birth_card_b` are abbreviated; on the wire they match [`get_card_for_birthdate`](/tools/get-card-for-birthdate) shape.

**Full payload / raw JSON:** call this tool — live response is the complete object (no verbosity flag). Chat may summarize; ask for the raw tool result if the UI truncates.

## Example response

```json theme={null}
{
  "flags": {
    "is_same_card": false,
    "is_self_pair": false,
    "is_wild_card": false
  },
  "summary": "Compatibility: birth_card_* = full cosmic block (classical_element + periodic_element); true_sidereal informational (v1 policy, not in overall_score); date_context 1900-2100.",
  "life_path_a": 5,
  "life_path_b": 2,
  "birth_card_a": "… full cosmic block: card, tarot, zodiacs, moon phase, season, retrogrades, runes, I Ching, and more …",
  "birth_card_b": "… full cosmic block (same shape) …",
  "date_context": {
    "birth_date_a": "full",
    "birth_date_b": "full"
  },
  "true_sidereal_a": "…",
  "true_sidereal_b": "…",
  "card_connections": [
    {
      "type": "jupiter",
      "direction": "a_to_b",
      "planet_to_planet": "harmonious"
    }
  ],
  "element_to_element": "neutral",
  "compatibility_score": {
    "bonuses": {
      "element_bonus": 0,
      "scoring_policy": "v1",
      "same_card_match": 0,
      "self_pair_penalty": 0,
      "ruling_planet_bonus": 0,
      "true_sidereal_bonus": -1,
      "chinese_zodiac_bonus": -2
    },
    "card_score": {
      "a_to_b": 3,
      "b_to_a": 0,
      "combined": 3,
      "connection_count_total": 1
    },
    "overall_score": 1,
    "interpretation": "neutral",
    "ruling_planet_to_planet": {
      "a_to_b": "neutral",
      "b_to_a": "neutral",
      "bonus_score": 0,
      "card_a_planet": "mars",
      "card_b_planet": "venus"
    }
  },
  "true_sidereal_aspect": "quincunx",
  "chinese_zodiac_aspect": "quincunx"
}
```

## Related

* [get\_card\_for\_birthdate](/tools/get-card-for-birthdate) — one date identity
* [get\_day\_card](/tools/get-day-card) — calendar day