hashicorp/nomad · error

Got 0 byte response with non-nil decode object

Error message

Got 0 byte response with non-nil decode object

What it means

decodeBody guard: the HTTP response has ContentLength 0 but a non-nil decode target was supplied, so there is no body to JSON-decode. Indicates an unexpected empty response from the server for an API call that should return data.

Source

Thrown at api/api.go:1232

	header := resp.Header

	// Parse the X-Nomad-Index
	index, err := strconv.ParseUint(header.Get("X-Nomad-Index"), 10, 64)
	if err != nil {
		return fmt.Errorf("Failed to parse X-Nomad-Index: %v", err)
	}
	q.LastIndex = index
	return nil
}

// decodeBody is used to JSON decode a body
func decodeBody(resp *http.Response, out any) error {
	switch resp.ContentLength {
	case 0:
		if out == nil {
			return nil
		}
		return errors.New("Got 0 byte response with non-nil decode object")
	default:
		dec := json.NewDecoder(resp.Body)
		return dec.Decode(out)
	}
}

// encodeBody prepares the reader to serve as the request body.
//
// Returns the `obj` input if it is a raw io.Reader object; otherwise
// returns a reader of the json format of the passed argument.
func encodeBody(obj any) (io.Reader, error) {
	if reader, ok := obj.(io.Reader); ok {
		return reader, nil
	}

	buf := bytes.NewBuffer(nil)
	enc := json.NewEncoder(buf)
	if err := enc.Encode(obj); err != nil {

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Check the Nomad server version/endpoint — the endpoint may legitimately return an empty body
2. Pass nil as the out object if the response is expected to be empty
3. Inspect server logs for a handler that failed to write a body

When it happens

Trigger: Thrown at api/api.go:1232 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/df40bdd357a949ea. Report an issue: GitHub.