v3.0.0

Breaking changes

• Path signing now follows AWS service defaults: S3 paths remain single-encoded,
  while other services use double-encoded, normalized paths. Explicit
  doubleUrlEncode values still override the default; set it to false to
  preserve the previous non-S3 behavior.
• SigV4Client.fetch() now owns its signing path and no longer invokes an
  overridden sign() method. Put logging, instrumentation, and transport policy
  in the custom transport instead.
• SigV4Client.fetch() now sends with redirect: "manual", rejects automatic
  redirect following, and rejects mode: "no-cors". Submit an accepted redirect
  target as a new signed request.
• Request input bodies are transferred instead of cloned, avoiding an unread
  tee branch. Create separate requests from replayable bytes when the original
  request must remain reusable.
• Credential service and region values must be lowercase. Entries in
  unsignableHeaders must be valid header names and can no longer exclude
  request x-amz-* headers or S3 content-md5.
• Retry counts must be non-negative safe integers. Retry counts and delay bounds
  reject explicit null instead of treating it as a default.

Added

• signAwsRequest() now accepts a signal, and SigV4RequestInit exposes
  duplex?: "half" for streaming request bodies.

Changed

• Signing and retries now use a stable snapshot of the effective target, request
  state, options, headers, and mutable or replayable body data. Retry attempts
  reuse the materialized body and payload hash without repeating library-level
  snapshotting, materialization, or hashing.
• Public types now match the runtime contracts: custom transports use
  (request: Request) => Promise<Response>, unsignableHeaders excludes bare
  strings, and SigningKeyCache.get() may return null for a cache miss.
• Client credentials and transport configuration use native private fields, and
  concurrent cold-cache signing for one credential scope shares a signing-key
  derivation.

Fixed

• Raw string URLs now receive the required second path-encoding pass for
  double-encoded services. Raw controls and other characters that cannot survive
  transport unchanged are rejected instead of producing unverifiable signatures.
• Request signal/body inheritance now follows platform semantics. Used Request
  bodies, disturbed or locked streams, unsupported body objects, non-standard
  async iterables, and Fetch-forbidden client methods fail before transport;
  bodies remain stable whenever hashing or retry replay requires fixed bytes.
• Redirect handling now works on workerd. Custom transports fail closed after
  redirects or cancellation, and exact abort reasons propagate through body
  handling, transport, response cleanup, and retry waits.
• Malformed UTF-16 secret access keys are now rejected because UTF-8 replacement
  could otherwise alias distinct JavaScript strings; well-formed Unicode secrets
  remain supported.

Documentation and tooling

• Documented the supported runtime, HTTPS, body-memory, signed-header, cache,
  custom-transport, and real AWS S3 integration contracts.
• CI now exercises Lambda and S3 behavior on pinned workerd@1.20260701.1 with
  compatibility date 2026-07-01.
• Package validation checks the exact tarball and a strict consumer; S3
  integration requires an explicit mode, and both registries receive the same
  validated artifact after the required main-branch CI jobs pass.