---
title: "Authentication"
description: "Send a FlightQueue API key in the X-API-Key header or the Authorization Bearer header."
---

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

# Authentication

Every `/api/v1` request needs an API key. Send the key in one of two headers:

```bash
curl -H "X-API-Key: fq_live_your_key" "https://flightqueue.com/api/v1/airports"
```

```bash
curl -H "Authorization: Bearer fq_live_your_key" "https://flightqueue.com/api/v1/airports"
```

Send one header, not both.

## Key types

| Prefix | Source | Access |
| --- | --- | --- |
| `fq_live_` | Developer key from your account | Pro and Enterprise plans |
| `fqagent_` | Agent key from `POST /api/agent/register` | Free endpoints and a 30 requests per minute limit |

Some endpoints need a specific plan. The reference lists the access level for each endpoint.

## Auth errors

| HTTP status | Code | Meaning |
| --- | --- | --- |
| 401 | `MISSING_API_KEY` | No key was sent. |
| 401 | `INVALID_API_KEY` | The key is unknown or revoked. |
| 403 | `PREMIUM_REQUIRED` | The key is valid but its plan does not include the endpoint. |
| 403 | `ENTERPRISE_REQUIRED` | The endpoint needs an Enterprise key. |

Keep keys in server-side configuration. Do not put them in browser code or public repositories.

Source: https://flightqueue.com/developers/reference/authentication/index.mdx