What causes "unsupported URL scheme: {http_url}" in BloopAI/vibe-kanban?

Prefix the configured URL with 'http://' or 'https://' before calling

unsupported URL scheme: {http_url}

Error message

unsupported URL scheme: {http_url}

What it means

http_to_ws_url converts an http:// or https:// base URL into its ws:// or wss:// WebSocket equivalent. Any URL without one of those two prefixes cannot be translated and is rejected, since the target scheme would be ambiguous.

Source

Thrown at crates/relay-tunnel-core/src/lib.rs:28

///
/// Increases the stream window size and write timeout over the defaults (256 KB / 10s)
/// to handle large HTTP responses over slow connections without triggering write timeouts.
pub(crate) fn yamux_config() -> YamuxConfig {
    YamuxConfig {
        max_stream_window_size: 1024 * 1024, // 1 MB (default: 256 KB)
        connection_write_timeout: Duration::from_secs(30), // (default: 10s)
        ..Default::default()
    }
}

/// Convert an HTTP(S) URL to its WebSocket equivalent (ws:// or wss://).
pub fn http_to_ws_url(http_url: &str) -> anyhow::Result<String> {
    if let Some(rest) = http_url.strip_prefix("https://") {
        Ok(format!("wss://{rest}"))
    } else if let Some(rest) = http_url.strip_prefix("http://") {
        Ok(format!("ws://{rest}"))
    } else {
        anyhow::bail!("unsupported URL scheme: {http_url}")
    }
}

View on GitHub (pinned to 4deb7eca8f)

Solutions

Prefix the configured URL with 'http://' or 'https://' before calling
Validate the URL scheme at configuration load time
If the input may already be a ws URL, normalize/strip 'ws://' / 'wss://' first

Example fix

// before
let ws = http_to_ws_url("relay.example.com")?; // bails
// after
let ws = http_to_ws_url("https://relay.example.com")?; // "wss://relay.example.com"

Defensive patterns

Strategy: validation

Validate before calling

if !url.starts_with("http://") && !url.starts_with("https://") { panic!("relay server URL must start with http:// or https://"); }

Try / catch

let ws_url = http_to_ws_url(cfg.server_url).map_err(|e| ConfigError::InvalidServerUrl(e.to_string()))?;

Prevention

Validate configured URLs at startup, not at call time
Include scheme in example config/env var docs
Normalize inputs by auto-prefixing https:// when scheme missing

When it happens

Trigger: Calling http_to_ws_url with a URL missing a scheme (e.g. 'localhost:8080' or 'example.com'), or with a non-HTTP scheme like 'ftp://' or an already-ws URL.

Common situations: Config value for the relay server URL written without 'http://' prefix; user pasted a 'wss://' URL into an http-only setting; env var defaults lacking the scheme.

Related errors

AI-assisted analysis of BloopAI/vibe-kanban@4deb7eca8f (2026-08-29). Data as JSON: /api/errors/2dfa557b35c2b7de. Report an issue: GitHub.