---
title: "Get effective API and MCP capabilities"
method: GET
path: "/capabilities"
tags: ["Capabilities"]
---

# Get effective API and MCP capabilities

`GET /capabilities`

## Request

- Base URL: `https://shipmail.to/api/v1`
- URL: `https://shipmail.to/api/v1/capabilities`
- Auth: one of:
  - HTTP bearer
  - OAuth 2 (authorization code, authorization URL `https://shipmail.to/api/auth/oauth2/authorize`, token URL `https://shipmail.to/api/auth/oauth2/token`)

Return the authenticated API key's effective scopes, resource constraints, MCP tool catalog, and capability contract version.

## Headers

- `X-Shipmail-Organization` string

## Response `200`

Effective capabilities returned.

- CapabilitiesResponse
  - `capability_version` string, required: Semantic version of the server capability contract.
  - `scopes` string[], required
  - `constraints` object, required
    - `mailbox_ids` string[], nullable, required
    - `domain_ids` string[], nullable, required
    - `audience_ids` string[], nullable, required
    - `resource_semantics` 'legacy-intersection' | 'union-v2', required: How mailbox_ids and domain_ids combine. union-v2 grants the union; legacy-intersection preserves older keys.
  - `allowed_mcp_tools` string[], required

## Other responses

- `401`: Authentication failed.
- `429`: Rate limit exceeded.

---

[API](https://skmtc.dev/shipmail/apis/shipmail-api.md) · [All operations](https://skmtc.dev/shipmail/apis/shipmail-api/llms.txt) · [OpenAPI document](https://skmtc.dev/shipmail/apis/shipmail-api/revisions/2c23e59d7e30?raw)