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

# API reference

> Every endpoint of the FastCAC API.

The base URL is `https://api.fastcac.com/v1`. Authenticate with your API key as a bearer token:

```bash theme={null}
curl https://api.fastcac.com/v1/ping -H "Authorization: Bearer fc_test_..."
```

* Requests and responses are JSON, except document uploads (multipart) and the certificate and
  status report (PDF).
* Every response has a `FastCAC-Request-Id` header.
* Errors share [one format](https://docs.fastcac.com/api-basics/errors.md).
* Send an [`Idempotency-Key`](https://docs.fastcac.com/api-basics/idempotency) on `POST`s.
* Lists [paginate](https://docs.fastcac.com/api-basics/pagination.md) with `limit` and `starting_after`.
* Ids are prefixed with their type: `reg_`, `biz_`, `doc_`, `evt_`, `we_`, `org_`, `key_`.
* Timestamps are UTC, in ISO 8601 with a `Z`.

The machine-readable spec is at [`https://api.fastcac.com/v1/openapi.json`](https://api.fastcac.com/v1/openapi.json).


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