---
title: "GET /v1/installations/{id}/capability"
method: GET
path: "/v1/installations/{id}/capability"
---

# GET /v1/installations/{id}/capability

`GET /v1/installations/{id}/capability`

## Request

- The document declares no server URL.
- Auth: one of:
  - HTTP bearer
  - API key in cookie `__Secure-better-auth.session_token`

A current capability token for this installation's proxy. Re-fetchable; not a secret.

## Path parameters

- `id` string, required

## Response `200`

The request has succeeded.

- InstallationCapability: A signed statement of what an installation's proxy may deliver. Not a secret on its own.
  - `capability` string, required: The capability token, baked in as `FOUNDERMAIL_CAPABILITY`. The proxy presents it verbatim on every inbound message and never parses it — which is what keeps a JWT library out of an artifact we can never patch.
  - `domains` string[], required: The domains it names, so an installer can show what is about to be installed.

## Other responses

- `default`: An unexpected error response.

---

[API](https://skmtc.dev/foundermail/apis/org.md) - [All operations](https://skmtc.dev/foundermail/apis/org/llms.txt) - [OpenAPI document](https://skmtc.dev/foundermail/apis/org/revisions/8bbb36e378ab?raw)