feat: custom fetcher

[sittiponghaus]

Add custom fetcher support for export via VPC Bindings

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Note

Low Risk
Optional API with default fetch preserves existing behavior; custom fetch only affects OTLP HTTP export routing when configured.

Overview
Adds an optional fetcher (Fetcher['fetch']) so OTLP telemetry can be sent through a bound implementation (e.g. Workers VPC fetch) instead of only the global fetch.

OTLPTransport and OTLPTransportConfig accept fetcher, defaulting to fetch, and export requests use unwrap(this.fetcher). OTLPExporterConfig / OTLPExporter store the same optional fetcher in the constructor. README adds a Custom Fetcher example wiring trace exporter and log transport from env.VPC_BINDING.

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[sittiponghaus]

Is this repository open to contributions?

[ifharry]

Hey! yes it is - whats the usecase for this? (mb just noticed the think); right now we just use the default fetch under the hood, if you resolve the conflicts on this happy to merge, it should be allowed for the logger and tracer preferably! :)

[cursor]

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[cursor]

Custom fetcher unused in exporter

High Severity

OTLPExporter accepts and stores config.fetcher, but send still calls global fetch via unwrap(fetch) instead of this.fetcher. Custom fetchers (including VPC bindings shown in the README) are ignored for traces, while OTLPTransport correctly uses this.fetcher.

Additional Locations (1)

• src/exporter.ts#L16-L21

 

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