[dinwwwh]

Summary

toFetchBody and toNodeHttpBody now drop a content-type given with an undefined body, like the peer adapter, instead of keeping it and adding standard-server: none. Fastify and AWS Lambda pick this up through toNodeHttpBody.

An empty body has no media type, so it now reads back as undefined from the content headers alone, including where the receiver can't see standard-server (for example a cross-origin browser client without Access-Control-Expose-Headers). Keeping the header didn't help HEAD responses either: the added hint and the cleared content-length already made their headers differ from GET.

To send an empty response with your own headers, such as for HEAD, use an already-closed ReadableStream. The core README now says so.

Changes

• packages/fetch/src/body.ts, packages/node/src/body.ts: the undefined branch clears content-type and no longer calls getRequiredStandardBodyHint('none', …).
• Tests: the undefined encoder tests now pass a content-type and hint that must be dropped. Removed the undefined as html rows from the "keeps a given content-type" tables, and the undefined as text/html e2e row, which only asserted the body and is covered by the plain undefined row.
• packages/core/README.md: one sentence on empty bodies.

Breaking change

A content-type set with an undefined body is no longer sent. This reverts the empty-body part of #176 (released in v0.12.0).

Notes for reviewers

• A throwaway probe (not committed) sent an already-closed ReadableStream as a GET and HEAD response over Express 4/5, Fastify, h3, Hono, srvx, node:http/https/http2 and Bun.serve. Every transport answered without errors and kept the custom headers.
• Out of scope, found while probing: on node:http/https, Express and Fastify, a HEAD response whose stream doesn't end promptly stalls. Node sends HEAD headers only on end(), and the response is piped from the whole stream first, so an endless stream never responds. A closed stream is unaffected. Not fixed here.

Testing

• The updated undefined encoder tests fail on main and pass here.
• vitest run (1485 tests), the Bun tests, and uncheck (sherif, oxlint, oxfmt, tsc) pass locally.

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Generated by Claude Code

[pkg-pr-new]

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@standard-server/core

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@standard-server/fastify

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@standard-server/node

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@standard-server/peer

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@standard-server/shared

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commit: 17c7e22

[codspeed]

Merging this PR will not alter performance

1 warning

⚠️ 5 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

✅ 26 untouched benchmarks
⏩ 108 skipped benchmarks¹

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_{Comparing claude/laughing-bell-0opftl (17c7e22) with main (7636c00)²}

Footnotes

1. 108 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (23d3742) during the generation of this report, so 7636c00 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[pullfrog]

✅ No new issues found.

Reviewed changes

• toFetchBody / toNodeHttpBody empty-body branch — an undefined body now clears content-type (instead of emitting standard-server: none next to a caller-supplied content-type); standard-server and content-length were already cleared.
• Tests — the undefined encoder tests now pass content-type: text/html plus a standard-server: file hint and assert both are dropped; the redundant undefined as html / undefined as text/html rows were removed.
• Core README — documents that an empty body is sent without content-type, and points to an already-closed ReadableStream for an empty response carrying custom headers.

I confirmed the receiver side still resolves none from the cleared headers (no content-type, content-length absent/0 → none, packages/core/src/utils.ts:123), that the peer adapter already drops content-type for undefined (packages/peer/src/body.ts:174), and that fastify/aws-lambda route through toNodeHttpBody. Full suite passes (1485 tests).

  ^{｜ View workflow run ｜ Using deepseek-v4.1-flash (free via Pullfrog for OSS) ｜ 𝕏}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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