40100 Authentication Failed

TikTok's API server could not authenticate your request. This is distinct from an invalid token—it means the authentication mechanism itself failed, often because headers are completely missing or malformed.

What causes this error?

TikTok’s API server could not authenticate your request. This is distinct from an invalid token—it means the authentication mechanism itself failed, often because headers are completely missing or malformed.

How to fix it

1. Check headers: Ensure Access-Token is included as a header (not a query parameter).
2. Verify app status: Make sure your TikTok developer application hasn’t been suspended or deactivated.
3. Check IP allowlist: If you’ve configured IP restrictions on your app, verify the calling server’s IP is included.