Module progress 

Progress-notification hook for long-running tools.

This module provides an additive, no-op-by-default surface that tools can use to emit progress events during execution. Callers that care about progress (e.g. a future MCP server wrapping Construct tools and forwarding notifications/progress) can supply a real ProgressSink; everyone else gets a NoopProgressSink and pays no cost.

Design

The Tool trait gained a new default method, [Tool::execute_with_progress], that takes a &dyn ProgressSink alongside the existing args. Its default body simply calls Tool::execute and drops the sink, so the ~93 existing tool implementations compile and behave exactly as before. Tool authors that want to emit progress opt in by overriding execute_with_progress.

MCP alignment

The ProgressSink::notify shape (progress_token, progress, total: Option<u64>, message: Option<&str>) mirrors the MCP notifications/progress payload so that a future adapter can forward events verbatim.

Structs

NoopProgressSink

Zero-cost sink used whenever a caller does not care about progress.

ProgressHandle

Ergonomic scoped handle: binds a ProgressToken to a ProgressSink so tool code can emit without repeating the token argument.

ProgressToken

Opaque token identifying a single progress stream.

Traits

ProgressSink

Sink that receives progress emissions from a running tool.

Functions

noop_sink

Process-wide default no-op sink, handed out when no sink is supplied.

Type Aliases

SharedProgressSink

Shared/owned sink alias, for callers that need to stash one in a struct.