ory/hydra · error · ErrServerError

server_error

server_error

Error message

ErrServerError.WithWrap(err).WithDebug(err.Error()).Error()

What it means

In WriteDeviceResponse, this expression is the server-error branch used when marshaling the DeviceResponse to JSON fails: the OAuth2 device-flow response cannot be serialized, and a generic RFC6749 server_error (500) is written instead. Marshal of a freshly built struct rarely fails, so reaching it indicates an internal inconsistency.

Source

Thrown at fosite/device_write.go:37

	}

	rw.Header().Set("Content-Type", "application/json;charset=UTF-8")
	rw.Header().Set("Cache-Control", "no-store")
	rw.Header().Set("Pragma", "no-cache")

	deviceResponse := &DeviceResponse{
		DeviceCode:              responder.GetDeviceCode(),
		UserCode:                responder.GetUserCode(),
		VerificationURI:         responder.GetVerificationURI(),
		VerificationURIComplete: responder.GetVerificationURIComplete(),
		ExpiresIn:               responder.GetExpiresIn(),
		Interval:                responder.GetInterval(),
	}

	r, err := json.Marshal(deviceResponse)
	_, _ = rw.Write(r)
	if err != nil {
		http.Error(rw, ErrServerError.WithWrap(err).WithDebug(err.Error()).Error(), http.StatusInternalServerError)
		return
	}
}

View on GitHub (pinned to 4174065ffb)

Solutions

1. Inspect the wrapped marshal error for the offending field in DeviceResponse
2. Treat as an internal server error; respond 500 with server_error per RFC 6749
3. Add tests covering the response shape so serialization regressions are caught in CI

When it happens

Trigger: Thrown at fosite/device_write.go:37 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ory/hydra@4174065ffb (2026-09-03). Data as JSON: /api/errors/e847e53cc6e9f6ef. Report an issue: GitHub.