Every request to the Footstep API must include an API key. This page explains how keys work, what happens when authentication fails, and how to keep your keys secure.Documentation Index
Fetch the complete documentation index at: https://docs.footstep.ai/llms.txt
Use this file to discover all available pages before exploring further.
How it works
Pass your API key in thex-api-key header on every request. The API validates the key before processing. If it’s missing, malformed, or invalid, the request is rejected immediately.
The MCP server also accepts the standard
Authorization: Bearer <key> form for compatibility with MCP SDKs whose default is Bearer authentication. Either header is fine; x-api-key is the recommended form across all Footstep surfaces.Key format
All API keys follow the formatsk_live_* (e.g. sk_live_abc123def456). If the key you’re sending doesn’t start with sk_live_, the API will reject it with a 401.
Create and manage keys at console.footstep.ai.
Key states
Keys can be in one of several states. The API checks the key’s state and your account balance on every request:| State | HTTP status | Error message | What to do |
|---|---|---|---|
| Active | 200 | - | Key is working normally |
| Insufficient balance | 402 | Insufficient balance. Please top up your account. | Top up your account at console.footstep.ai. The key itself is fine — only the balance is blocking the request |
| Suspended | 403 | API key is suspended | Contact support. Your key has been temporarily disabled |
| Revoked | 403 | API key has been revoked | Generate a new key in the console. Revoked keys cannot be reactivated |
| Not found | 403 | Invalid API key | Check for typos. If correct, the key may have been deleted |
| Missing or malformed | 401 | Missing or invalid API key format | Ensure you’re sending the x-api-key header with a valid sk_live_* key |
A
401 means the request had no valid key at all. A 402 means the key is valid and active but your account has no credit — top up to resume requests. A 403 means the key was recognised but isn’t allowed: it’s been suspended, revoked, or doesn’t exist.Security best practices
- Use environment variables. Store keys in
FOOTSTEP_API_KEYor your platform’s secret manager, not in source code. - Never include keys in query strings. Query strings appear in server logs, browser history, and CDN caches. Always use the
x-api-keyheader. - Rotate keys regularly. Generate a new key in the console, update your services, then revoke the old one.
- Use separate keys per environment. Different keys for development, staging, and production make it easier to rotate and audit.
- Restrict access. Only share keys with services that need them. If a key is compromised, revoke it immediately and generate a replacement.