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DevTools

High-level layers for connecting an Effect runtime to the unstable devtools tracer.

DevTools is the application-facing entry point for installing a tracer that mirrors the current tracer and streams spans, span events, span completions, and metric snapshots to an external devtools process. Lower-level socket protocol details live in DevToolsClient.

3 exports Added in v4.0.0 Source

Layers

layer

Added in v4.0.0 Source

Layer that installs the devtools tracer over a WebSocket connection using the global WebSocket constructor, defaulting to ws://localhost:34437.

When to use

Use to stream Effect tracing and metrics telemetry to a devtools process when the runtime environment already provides a global WebSocket constructor.

Details

This is a convenience wrapper around layerWebSocket(url) that provides Socket.layerWebSocketConstructorGlobal, so the resulting layer has no remaining requirements.

Gotchas

This layer only installs the client-side tracer; it does not start a devtools server, so the configured WebSocket endpoint must already be reachable. It relies on globalThis.WebSocket being available in the runtime.

See

  • layerWebSocket for installing the devtools tracer with an explicit WebSocketConstructor requirement
  • layerSocket for installing the devtools tracer over an existing Socket transport

Signature

declare function layer(url: string): Layer<never>;

layerSocket

Added in v4.0.0 Source

Layer that installs the devtools tracer using an existing Socket.

Signature

declare const layerSocket: Layer.Layer<never, never, Socket.Socket>;

layerWebSocket

Added in v4.0.0 Source

Layer that installs the devtools tracer over a WebSocket connection to the specified URL, defaulting to ws://localhost:34437.

Signature

declare function layerWebSocket(url: string): Layer<never, never, WebSocketConstructor>;