OptionalbodyOptionalheadersOptionalmaxHard cap on the response body size in bytes; the request aborts if exceeded.
OptionalredirectAlways "manual": a transport must not follow redirects itself (fetch(url, { redirect: request.redirect })). The engine follows them, with its own rules for which hop gets the
base URL's credentials. A transport that reports a final url on another origin anyway
makes the call fail.
OptionalsignalAborted when the engine's overall deadline (timeoutMs) passes. A transport should stop
the request then (fetch(url, { signal })); the engine rejects at the deadline either way,
and enforces maxResponseBytes on the body it gets back, so neither limit depends on it.
OptionaltimeoutTimeout for the whole request, response body included, in milliseconds.
Fully-qualified absolute URL.
Optional request body (already serialised).