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

# Connect API error types

> Interpret Connect API error names and decide whether to correct the request, check access or retry.

Connect APIs use HTTP status codes and structured error responses. Check the endpoint's response schema and error details before retrying. For Observe, use its separate [errors and limits guide](/api-reference/observe/errors).

## internal\_error

An internal operation failed. Retry reads with backoff. Before retrying a write, check whether it already took effect. Contact support with the request details if the failure persists.

## not\_found

The requested resource could not be found. Check the resource ID and the project selected by your credentials.

## method\_not\_allowed

The endpoint does not support the HTTP method you used. Check the method in the endpoint reference.

## validation\_error

One or more request fields failed validation. Use the field details in the response to correct the request before retrying.

A request from an origin that is not authorized for the project also returns `validation_error`, with a message naming the origin. Check the origin configured for your web integration and the project's authorized origins.

## login\_error

Authentication or authorization failed. Check the [credential format](/api-reference/connect/authentication), the key's permissions, expiry and IP restrictions. Use the HTTP status to distinguish missing or invalid authentication from denied access.

A project ID in the query, header or path that does not match the project of your credentials also returns `login_error`.

## invalid\_json

The request body could not be parsed as JSON. Check JSON syntax and send a valid JSON body.

## rate\_limited

The request exceeded a rate limit. Reduce request frequency and retry with backoff, honoring `Retry-After` when provided. Limits depend on the service and deployment configuration; do not assume one fixed limit applies to every endpoint.

## already\_exists

The resource already exists or a uniqueness constraint would be violated. Look up the existing resource before attempting another create request.

## wrong\_content\_type

The request uses an unsupported content type. Use the content type declared by the endpoint, typically `application/json` for JSON request bodies.

## client\_error

The service classified the failure as a client-side request error. Inspect the response details and the endpoint's requirements before retrying.

## source

The `X-Corbado-Source` header contains an unsupported value. Corbado SDKs set this header themselves; when you call the API directly, omit it.

For [signed-passkey verification](/api-reference/connect/backend/passkeys/verify-signedpasskeydata-from-a-passkey-login), create an application session only when the HTTP request succeeds and `verificationResult` is `success`. A successful HTTP status alone does not establish a successful login.