Fetch Request Streaming

[dandclark]

Description

Fetch request streaming allows developers to create a fetch request with a ReadableStream body. This can be used for uploading streaming data, or for talking to a streaming endpoint without requiring an intermediary.

Tests: https://wpt.fyi/results/fetch/api/basic?label=experimental&label=master&aligned&q=fetch%2Fapi%2Fbasic%2Frequest-upload

Specification

https://fetch.spec.whatwg.org/#concept-body-stream

Additional Signals

• Upvoted responses at https://stackoverflow.com/questions/35711724/upload-progress-indicators-for-fetch discussing fetch upload streaming
• Many positive developer comments on Uploading a Request made from a ReadableStream body whatwg/fetch#425
• Use cases discussed by developers at https://groups.google.com/a/chromium.org/g/blink-network-dev/c/bsVgOxNCzFc
• 73 +1s on https://issues.chromium.org/issues/40505032

[wpt-interop]

Thank you for proposing Fetch Request Streaming for inclusion in Interop 2025.

We wanted to let you know that this proposal was not selected to be part of Interop this year.

On behalf of the entire Interop team, thank you for submitting this proposal for consideration. We got many more proposals than we could include in this year's project, necessitating some difficult choices. Please note this should not be taken as a comment on the technology as a whole, or our willingness to consider it for Interop in the future. We appreciate the work you put into your proposal, and would welcome your participation in future rounds of Interop.

For an overview of our process, see proposal selection. Thank you again for contributing to Interop 2025.

Posted on behalf of the Interop team.