# Keys and authentication

How FynePDF API keys work - live and test keys, the Authorization header, request IDs and safe retries.

## Send your key

Every request carries an API key as a bearer token:

```bash
curl https://api.fynepdf.com/v1/me \
  -H "Authorization: Bearer $FYNEPDF_API_KEY"
```

Make keys in [Developers, API keys](https://fynepdf.com/developers/dashboard?section=keys). The full key is shown once; we keep only a hash, so a lost key can't be shown again, only replaced. An account can hold up to 10 keys.

## Live and test keys

| | Live key `fyne_live_…` | Test key `fyne_test_…` |
|---|---|---|
| Cost | Spends credits | Free |
| PDFs | As made | "FynePDF test key" across every page |
| Word, Excel, images, Markdown… | As made | The first 3 pages only |
| AI calls | Real answers | Sample answers, marked as samples |
| Largest file | 50 MB, 250 MB after buying credits | 10 MB |
| Jobs a day | No daily limit | 100 per account |

Live keys need a verified email address on the account. Build against a test key, then swap it for a live one; nothing else changes.

## Keep keys secret

- Call the API from your server, never from a browser or a mobile app.
- One key per place it runs ("Production server", "Staging"), so you can revoke one without touching the others.
- Revoking a key stops it at once: [Developers, API keys](https://fynepdf.com/developers/dashboard?section=keys).

## Request IDs

Every response has a `Request-Id` header (`req_…`), errors included. Quote it to support and we can find the call.

## Safe retries

Send an `Idempotency-Key` header with any `POST`. If the same key comes again within 24 hours, you get the first answer back and nothing runs or charges twice. Use a new key (a UUID) for each new request.

```bash
curl https://api.fynepdf.com/v1/jobs \
  -H "Authorization: Bearer $FYNEPDF_API_KEY" \
  -H "Idempotency-Key: 6f1c2b8e-1d7a-4f0e-9a51-2c8f0b4d9e31" \
  -H "Content-Type: application/json" \
  -d '{"inputs":["file_01jc8x4m2k9q7r3t5vwy6z"],"steps":[{"action":"ocr"}]}'
```

## Assistants don't need a key

Claude, ChatGPT and other assistants connect to the MCP server (`https://api.fynepdf.com/mcp`) by signing in with a FynePDF account, and use that account's plan. API keys also work there as bearer tokens, for agents you run yourself.


---

Open this page in a browser: https://fynepdf.com/developers/docs/authentication

More: [All tools](https://fynepdf.com/tools) · [AI agents](https://fynepdf.com/ai/agents) · [llms.txt](https://fynepdf.com/llms.txt) · [Sitemap](https://fynepdf.com/sitemap.xml)