What causes "streams: source empty" in AlexxIT/go2rtc?

Add or fix the src query parameter in the request URL, e.g. /api/ws?src=camera1

streams: source empty

Error message

streams: source empty

What it means

GetOrPatch reads the `src` query parameter to locate or create a stream; when the parameter is absent or empty the request is meaningless, so the API handlers (WSHLS, MP4, WS, MSE, keyframe endpoints) return this error.

Solutions

Add or fix the src query parameter in the request URL, e.g. /api/ws?src=camera1
Verify the variable holding the stream name in the client/template isn't empty at request time
When calling GetOrPatch directly, validate that query.Get("src") != "" before calling

Example fix

// before
const ws = new WebSocket(`ws://host/api/ws?src=${name}`); // name === ""
// after
if (!name) throw new Error("stream name required");
const ws = new WebSocket(`ws://host/api/ws?src=${encodeURIComponent(name)}`);

Defensive patterns

Strategy: validation

Validate before calling

if query.Get("src") == "" {
	return errors.New("src query parameter is required")
}
stream, err := streams.GetOrPatch(query)

Try / catch

stream, err := streams.GetOrPatch(query)
if err != nil {
	http.Error(w, "missing 'src' query parameter", http.StatusBadRequest)
	return
}

Prevention

Always build stream consumer URLs with the src parameter
Use URL templates in player code with required src validation
Return HTTP 400 with a clear message in custom handlers when src is missing

When it happens

Trigger: Calling any stream consumer endpoint (e.g. /api/ws, /api/stream.mp4, /api/stream.m3u8) without `?src=...`, or with `src=` empty; programmatically calling streams.GetOrPatch(url.Values{}) with no src key.

Common situations: Embedded player code built with the stream name omitted; HTML templates that interpolate an empty src variable; frontend URL built after stream name fetch failed silently.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of AlexxIT/go2rtc@c245815e75 (2026-09-07). Data as JSON: /api/errors/921bae4891f7ae57. Report an issue: GitHub.

Appendix: source

Thrown at internal/streams/streams.go:122

	}

	// check an existing stream with this name
	if stream, ok := streams[name]; ok {
		stream.SetSource(source)
		return stream, nil
	}

	// create new stream with this name
	stream := NewStream(source)
	streams[name] = stream
	return stream, nil
}

func GetOrPatch(query url.Values) (*Stream, error) {
	// check if src param exists
	source := query.Get("src")
	if source == "" {
		return nil, errors.New("streams: source empty")
	}

	// check if src is stream name
	if stream := Get(source); stream != nil {
		return stream, nil
	}

	// check if name param provided
	if name := query.Get("name"); name != "" {
		return Patch(name, source)
	}

	// return new stream with src as name
	return Patch(source, source)
}

var log zerolog.Logger

View on GitHub (pinned to c245815e75)