`ReadableStream.cancel()` adopts the underlying source's cancel promise,
which is permitted never to settle — so awaiting `releaseBody` while
propagating a cancellation can hang the very thing it was meant to end.
The five exceptional exits in the compat probe loop now start the
release without waiting on it: the release is a courtesy to the
connection pool, and the caller's abort or timeout must reach it
regardless. The two non-exceptional awaits are unchanged.
Same class as the tee teardown in round 24, one file over.
Also moves the `redactUrlQuery` import above
DEFAULT_OAUTH_REQUEST_TIMEOUT_MS's JSDoc, which it had split from the
constant — so hover and API tooling see the doc again.
Verified by mutation: awaiting the release makes the new test time out.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Losing the race rejected the caller but did not stop the read. Because
clone() tees the body, a drain still running kept pulling bytes AND
kept buffering them for the unread original branch — unbounded memory
on exactly the signal-ignoring body the race exists to contain.
The clone is now drained through an explicit reader rather than
clone().arrayBuffer(), precisely so the losing side has something it
can cancel: arrayBuffer() locks the stream to an internal reader
nothing else can reach. On any throw both branches are torn down, which
is safe because that path never hands the response to a caller.
The cancels are deliberately not awaited: cancelling one branch of a
tee can itself wait on the other, which would hold the timeout open for
as long as the stall it is meant to end. Each carries its own catch, so
a stream already cancelled, errored or locked elsewhere does not mask
the timeout the caller actually needs — covered by a test whose stream
throws from cancel().
Verified by mutation: removing the teardown makes the new test fail.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
The timeout message interpolated the raw request URL, and
createFetchTracker records that message verbatim into the Network log
and the persisted session. An OAuth endpoint's query string can carry a
`code`, an `access_token` or a `client_secret` — exactly the fields
fetchTracking already redacts everywhere else it records a URL — so a
stalled signed endpoint would have written its secret to both.
Redacted with the existing `redactUrlQuery`, in the
OAuthRequestTimeoutError constructor rather than at each display site,
so both the message and the public `url` field are covered by
construction and no future consumer can reintroduce it. The route's own
proxied-timeout message and the URL in its 504 marker get the same
treatment, since both cross back to the browser and are recorded there.
The path and every non-sensitive parameter survive, so the endpoint
stays identifiable — which was the point of naming it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Rebuilding a Response around the buffered bytes could never be
faithful. `url`, `redirected` and `type` are internal slots, so
shadowing them as own properties satisfied a direct read and was lost
the moment a caller called clone() — which returns a fresh native
Response. The headers guard differed too, and the decoded bytes made
the inherited content-encoding and content-length wrong, so those had
to be stripped: four observable differences from the response fetch
actually produced.
The wrapper now drains `response.clone()` under the deadline and
returns the original. Cloning tees the body, so draining one branch
buffers the other: the bound is unchanged, the caller reads without a
second trip, and every native slot stays intact. rebuildResponse and
its null-body handling are gone, and with them the whole class.
Also: getServerUrl() throws for a non-HTTP configuration, and this
wrapped fetch can still be handed to a transport or a custom factory
that calls it — so the documented fail-open was reachable only until
that getter threw, at which point a configuration error propagated out
of a fetch. Caught, for the same reason readNegotiatesEndpoint catches.
Tests: response identity, the body still readable after the drain, a
re-clone keeping its metadata (the case a rebuild could not satisfy),
content-encoding preserved because nothing invalidates it now, a
null-body status passed through, and the throwing getter failing open
while still not slipping past the form-encoded check.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
The exemption was URL-only, so an authorization server configured at
the MCP endpoint's own URL — `oauthTokenUrl` takes any absolute URL —
made the transport-internal refresh take the exempt branch and run with
no signal, no body buffering and no deadline. That is the one request
this change exists to bound.
`isExempt` now receives the request's headers as well as its URL, and
`exemptMcpEndpoint` refuses to exempt anything sent as
`application/x-www-form-urlencoded`, before any URL comparison. That is
a discriminator rather than a heuristic: the token exchange, the
refresh and revocation are all form-encoded per RFC 6749 §4.1.3 and RFC
7009 §2.1, and MCP is JSON-RPC over application/json and never is.
Also records, on the no-deadline route test, what it does not catch: at
a 400ms wait an unconditional timer restored at the production 30s
budget would still leave the request pending and the test would pass.
Catching that needs either a ~31s wait on every CI run or a route-level
deadline knob existing only for the test, and a second source of truth
for the deadline is the defect round 13 removed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Round 17 widened exemptMcpEndpoint to the origin for everything, which
exempted same-origin OAuth work as well as MCP traffic — on the very
401/discovery path #2319 exists to bound.
The rule is now as narrow as each transport allows. Streamable HTTP
sends every MCP request to the configured URL, so origin + pathname is
exact there and same-origin OAuth stays bounded. Legacy SSE negotiates
its message endpoint inside the stream, where we never see it, so the
origin rule is the narrowest available — and it is exact rather than
approximate, since the SDK enforces that the message endpoint shares
the stream URL's origin.
The residual gap is therefore confined to legacy SSE against a server
hosting its own OAuth endpoints, and it is stated in the docblock and
pinned by a test rather than left implicit. Neither alternative was
reachable: the SDK takes a single fetch for all network requests, so
there is no separate auth seam to route through, and the negotiated SSE
endpoint is parsed inside the SDK's own stream handler.
Fails open on every uncertainty, including not knowing the transport —
a path rule applied to what turns out to be SSE severs real MCP
traffic, so an absent or throwing hint falls back to the origin rule.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
exemptMcpEndpoint compared origin + pathname, which misses legacy SSE
entirely: SSEClientTransport opens the configured URL and is handed a
SEPARATE message endpoint by the server, then POSTs every JSON-RPC
message to that second pathname. Those were bounded and body-buffered
as OAuth traffic, so a slow tool call over SSE would be severed at 30s
and reported as an OAuthRequestTimeoutError.
It compares origin alone now. That is exact rather than approximate:
the SDK enforces that the SSE message endpoint shares the stream URL's
origin and rejects one that does not, so every MCP request this chain
carries is same-origin with the configured URL by construction.
The cost, stated in the docblock and pinned by a test: an OAuth
endpoint on the MCP server's own origin is exempt here and so unbounded
on this chain. The OAuth chain still bounds the Inspector's own
requests to it, so only the SDK's transport-internal OAuth against a
same-origin server falls back to where it was before #2319.
Caller cancellation was also still swallowed in two later places in the
compat probe loop — `probe.text()` has its own catch, and `fetch`
resolves on headers, so an abort mid-body landed there and was answered
with the preceding 404; and an abort during releaseBody's await would
have carried on probing. Both recheck the signal now, and all three
sites throw the caller's own `reason` rather than whatever shape the
layer beneath rejected with.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Two real bugs and two stale rationales.
The OIDC fallback probes were issued with `{ headers }` and no signal,
so a caller that aborted after the initial 404 got a timeout reported
in place of its own cancellation, while the probe ran on to its own
deadline. The probes now carry the caller's signal — via the shared
`callerSignalOf`, so the precedence rule has one definition — a
pre-aborted caller is not probed at all, and an abort is rethrown
rather than folded back into the preceding response.
`Math.max(0, Math.round(timeoutMs))` let NaN and Infinity through.
`setTimeout(fn, NaN)` fires immediately, and a delay above 2**31-1
overflows a 32-bit signed int and falls back to 1ms — so a caller
asking for a very large budget, or one whose arithmetic produced NaN,
got an immediate OAuth timeout. `normalizeBudget` falls back to the
default on non-finite and clamps to the timer's range; the route's
envelope-supplied deadline gets the same clamp, but ignores a
non-finite value outright since a malformed deadline reads safest as
no deadline.
The wire-marker docblock and the matching route test still said a
backend deadline is the only one on the transport-internal discovery
path, which round 11 changed. Both now give the real reason the marker
matters: both ends run the same budget, and it is the backend winning
the race — a backgrounded tab throttling setTimeout — that must not
decide whether the error names its endpoint.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Three comments still said transport-internal discovery has no
client-side wrapper, or that the wrapper must never be applied to the
transport fetch. Round 11 made both false, and the second actively
tells a caller to do the opposite of what InspectorClient does — while
hiding that isExempt is the safety-critical part.
- createRemoteFetch's marker comment now gives the real reason the
reconstruction matters: both ends run the same budget, so this path
is the backend winning the race, most plausibly a backgrounded tab
throttling setTimeout while the server's fires on schedule. Which
deadline fired must not decide whether the error names its endpoint.
- The body-buffering comment now says buffering is the second reason
isExempt is not optional on a mixed chain, since an exempt request
skips it and an SSE body stays open rather than being drained.
- The matching test comment is reframed as testing the proxy boundary
independently of which deadline wins.
The PR description is rewritten around what is actually shipped: both
chains bounded and differing only in the exemption, the per-request
envelope that replaced the fetchTimeoutMs option, and the three
mutation-verified tests.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
The server-side timer added in round 9 applied to every /api/fetch
request. But that route carries MCP traffic as well as OAuth work, so a
Streamable HTTP tool call that legitimately withholds its response
headers past the budget was aborted there — reintroducing on the
backend exactly the regression exemptMcpEndpoint prevents on the
client, and reporting it as an OAuth timeout besides.
The caller now decides. `withOAuthRequestTimeout` stamps its budget on
the RequestInit it hands down, `createRemoteFetch` reads it back and
puts it in the /api/fetch envelope, and the route applies a timer only
when one is present — so an exempt MCP request, which never gets an
init of its own, is bounded by nothing.
The carrier is a WeakMap keyed on the init rather than a header:
serializeRequest copies request headers verbatim into the payload and
the route re-sends them to the authorization server, so a marker header
would leak to a third party. It needs no cast onto RequestInit and is
collected with the object.
The `fetchTimeoutMs` option from round 9 is gone — the deadline now
lives in exactly one place, the client wrapper, which is also what
makes the 504 marker honest: only a request the OAuth wrapper bounded
can produce one.
Ten tests: the stamping and its rounding, nothing stamped on an exempt
call or an init that never went through the wrapper, the envelope
carrying the budget (and not a header), its omission on both exempt and
direct calls, and at the route the 504 marker, no deadline without one,
and a non-numeric deadline ignored. The no-deadline case is verified by
mutation: an unconditional timer makes it fail.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Copying url/redirected/type onto the rebuilt response as enumerable own
properties changed what a consumer sees: `Object.keys`, object spread
and `JSON.stringify` are all affected. Which answer is correct turns
out to be the host's business — under the Fetch standard these are
prototype getters with no own enumerable key, while happy-dom defines
them as own enumerable data properties — so the descriptor is copied
from the freshly built Response rather than either answer being
hardcoded. The test compares against a baseline built in the same
runtime for the same reason.
Three comments still described the transport fetch as unbounded, which
round 11 changed:
- the wrapper's own docblock said it must never wrap the transport,
obscuring that isExempt is what makes doing so safe;
- the auth-chain comment in inspectorClient repeated it;
- buildEffectiveAuthFetch's docblock said transport-internal discovery
is not covered by a deadline.
All three now state the real distinction — both chains are bounded, and
they differ only in that the transport chain exempts the MCP endpoint —
and the docblock says why reusing the transport chain here would be
wrong rather than merely different.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
The transport chain carried the SDK's own OAuth work — the discovery it
runs from inside the transport on the 401/refresh path — and that leg
was left to the SDK's incidental per-request timeout, reporting a bare
`Request timed out` naming no endpoint. On a direct (non-proxied) path
the /api/fetch backstop cannot reach it either.
`withOAuthRequestTimeout` takes an optional `isExempt` predicate; an
exempt request passes through completely untouched — no deadline, no
signal, and no body buffering, which is what a stream needs.
`exemptMcpEndpoint` exempts the MCP endpoint by origin + pathname, and
FAILS OPEN: no server URL, or either side unparseable, means exempt.
The errors are not symmetric. Bounding what should not be bounded
severs a long-running tool call withholding its headers, or an SSE
body; failing to bound leaves the SDK's timeout as the backstop it
already was.
Two test corrections, both real:
- The metadata-preservation case asserted url/redirected/type against a
synthetic Response, whose values are the rebuild's own defaults — so
it stayed green with the defineProperty loop deleted. It now seeds
non-default values first; verified by mutation that removing the loop
makes it fail.
- Two signal assertions compared against the controller rather than
`request.signal`. The Fetch standard gives a Request a dependent
signal, so those encoded non-standard identity.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
A deadline enforced by the backend could not arrive as an
OAuthRequestTimeoutError: /api/fetch serialized it as a 500 and
createRemoteFetch turned that into a plain Error, so every instanceof
check downstream was false — including the one that lets a stalled
probe escape withRfc8414OidcCompat. That matters most where no
client-side wrapper exists to have fired first: the discovery the SDK
runs from inside the transport. The route now answers 504 with a typed
marker (OAUTH_TIMEOUT_WIRE_CODE plus url and timeoutMs) and
createRemoteFetch reconstructs the error from it, guarded by a shape
check so an upstream's own JSON cannot forge one.
The route's deadline becomes a `fetchTimeoutMs` option defaulting to
the shared constant, so the backstop can be proven to fire in
milliseconds instead of thirty seconds of wall clock — and because a
very slow authorization server is a legitimate reason to want a longer
one.
The rounding rationale was wrong: setTimeout accepts a fractional delay
and truncates it (verified on Node 26); ERR_OUT_OF_RANGE is
AbortSignal.timeout's behaviour, which this wrapper never calls. The
rounding stays, for the reason that is actually true — the budget is
interpolated into the message and exposed as timeoutMs, and a
performance.now() budget would otherwise report 1000.4000000953674ms.
Also drops a sentence in the discarded-stream test that contradicted
the qualification above it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Three findings, all real.
`arrayBuffer()` hands back the decoded entity body, so the rebuilt
response was carrying the upstream `content-encoding` and the
compressed `content-length` — a gzipped metadata document came back as
plain JSON bytes still claiming gzip and the wrong size, visible in the
Network capture. Both headers are deleted now, as `responseWithBody` in
endpointOverrides.ts already did for the same reason.
The "why a race, and not just the signal" rationale described a world
this PR had since changed: the signal does now reach the backend's
outbound fetch. The module doc and three implementation comments are
rewritten to say what the race is actually still for — a fetchFn that
ignores AbortSignal, and a backend that is itself wedged — rather than
a proxy hop that no longer drops it.
The backend cancellation path had only mock-level coverage. A
route-level test drives /api/fetch at an upstream that accepts and never
answers, aborts the browser side, and asserts the upstream observes its
connection closing. Verified by mutation: dropping `signal` from the
route's outbound fetch makes it time out rather than pass.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Both findings are on the caller-signal handling added in round 1:
- `"signal" in init` treated a member present as `undefined` as an
explicit override. `RequestInit` is a WebIDL dictionary, where such a
member converts as absent — so `{ ...base, signal: undefined }`, which
is what a spread over an options object with no signal produces, was
clearing a Request's embedded signal instead of inheriting it. Only a
non-`undefined` value overrides now; an explicit `null` is still the
genuine no-signal case.
- An already-aborted caller signal rejected the race, but
`Promise.race` still evaluated `fetchFn(...)`, so on the
signal-dropping proxy path the OAuth request went out anyway. It now
short-circuits before anything is constructed or sent, and the
now-unreachable aborted branch inside the race is gone.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Three findings, all real:
- The deadline stopped at the response headers. `fetch` resolves once
headers arrive, so a server that sent headers — or half a JSON
document — and then stalled left the caller's `response.json()`
hanging with nothing watching it. The body is now buffered under the
same race and the response rebuilt around it, preserving `url`,
`redirected` and `type`, which have no constructor option, and
passing `null` for a null-body status.
- The caller's signal was only forwarded, not raced. On the browser's
`createRemoteFetch` path the signal is dropped in flight, so an abort
left the promise pending for the whole budget rather than the outer
cancellation winning as documented. It is raced now, with the
caller's own `reason` preserved, and the listener removed in
`finally` since one caller signal outlives several requests.
- A `Request` carries its signal on the input, not in `init`, so always
passing our own `signal` in `init` silently overrode it. The caller
signal is now derived from the `Request` when `init` has no `signal`
key — and an explicit `null` there still wins, per the fetch spec.
Eight new tests cover each: the stalled body, caller cancellation
against a signal-ignoring fetch, an already-aborted signal, the
Request-embedded signal, the explicit-null override, listener removal,
the rebuilt response's metadata and a null-body status.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
Protected-resource-metadata discovery, authorization-server metadata
discovery, dynamic client registration, the token exchange and the
refresh all went out with no AbortSignal at all. Token revocation was
the single exception, and its withDeadline race is the pattern this
generalizes.
Adds core/auth/requestTimeout.ts: withOAuthRequestTimeout wraps a fetch
so every call through it is bounded, composing any caller signal with
AbortSignal.any and racing a timer so the deadline holds even where the
signal is dropped in flight (the browser's remote fetch re-issues the
call to /api/fetch and forwards no signal). The rejection is an
OAuthRequestTimeoutError naming the URL, so a stall says which endpoint
stalled rather than riding the SDK handshake timeout and reporting
"Request timed out".
Applied inside InspectorClient.buildEffectiveAuthFetch rather than to
this.fetchFn, because the transport is handed this.fetchFn directly and
a deadline on a Streamable HTTP / SSE response would sever the stream it
is supposed to hold open. Also applied to the CLI's storedAuthFetch,
which calls SDK discovery directly and so has nothing else bounding it.
Closes#2319
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
