Invalid Client

URI: https://docs.ankatech.co/errors/invalid_client
HTTP Status: 401 Unauthorized

This error also corresponds to the RFC 6749 OAuth 2.0 error code invalid_client of the same name. The RFC 7807 type suffix uses the identical underscore form so the two identifiers match.

When you see this

Client authentication at the token endpoint failed — the client identity could not be verified.

Common Causes

An unknown or disabled client_id.
Missing or incorrect client credentials.
Using an unsupported client authentication method.

Response Example

{
  "type": "https://docs.ankatech.co/errors/invalid_client",
  "title": "Invalid Client",
  "status": 401,
  "detail": "Client authentication failed. The client could not be verified.",
  "instance": "/oauth/token",
  "correlationId": "550e8400-e29b-41d4-a716-446655440000",
  "timestamp": 1730000000
}

Content-Type: application/problem+json — the response follows RFC 7807 Problem Details.

How to Resolve

Verify the client_id and client secret (or other client credentials).
Confirm the client is registered and enabled.
Use a supported client authentication method and re-submit.

For full schema definitions, examples, and interactive testing, see the Developer Hub Reference.