<!-- Extension API v0 — pre-1.0. Interfaces may change without notice until P2 seals the custom-code format. First-party extensions track HEAD. -->

# `compat.check`

Check an artifact's compatibility with this platform version without installing it: {kind: css|bundle|extension|tree, artifact, kit?, variables?} → verdict {ok, breaking[], warnings[]} with TR messages and alias fixes. Public and side-effect-free (CLI `mozaik compat check`, Dev MCP).

- **method + path**: `POST /v1/compat/check`
- **TR label**: Uyumluluk denetimi
- **auth**: public · scope gates: none (public)
- **agentPolicy**: `quote` — a provider call with no store-state change (offers, labels, validators) — every token kind calls it directly.
- **effects**: none
- **idempotency**: server — the platform derives the key
- **wraps**: — (no command inside)

Machine-readable body schema: [/schemas/routes/compat.check.json](/schemas/routes/compat.check.json).

## Body

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "kind": {
      "type": "string",
      "enum": [
        "css",
        "bundle",
        "extension",
        "tree"
      ]
    },
    "artifact": {},
    "kit": {
      "type": "string",
      "pattern": "^[a-z][a-z0-9-]*\\.[a-z][a-z0-9-]*@\\d+$"
    },
    "variables": {
      "maxItems": 40,
      "type": "array",
      "items": {
        "type": "string",
        "maxLength": 40
      }
    }
  },
  "required": [
    "kind",
    "artifact"
  ],
  "additionalProperties": false
}
```