Add MCP_SANDBOX_FULL_ADDRESS and MCP_APP_ORIGIN_FULL_ADDRESS so a reverse
proxy or ingress deployment can advertise the sandbox proxy URL and the
_meta.ui.domain app origin the browser actually reaches, instead of the
bind-derived http://localhost:<port> ones. The process still listens on
MCP_SANDBOX_PORT / MCP_APP_ORIGIN_PORT.
Both values are validated in public-address.ts and refused (warned, bind-
derived address kept) when malformed or when their origin collapses onto
the Inspector UI's (or, for the app origin, the sandbox's) — the MCP Apps
spec requires host != sandbox origin, and the single-hostname proxy layout
is exactly the one that breaks it. Plain http under an https UI is warned.
The sandbox proxy page's referrer check was a hardcoded
http://localhost|127.0.0.1 pattern no https embedder could match. It now
compares the referrer's parsed origin against an exact list injected by the
controller, derived from the same filtered allow-list as its frame-ancestors
header, with the old loopback check kept only as the no-list fallback.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HzuzRPJv7M8wGe3wyw5sSg
Signed-off-by: cliffhall <cliff@futurescale.com>
- MCP_AUTO_OPEN_ENABLED: the TUI never reads it; the CLI's unset
default opens only on a stderr TTY. Migration guide row fixed too.
- Drop the blanket "empty equals unset" rule, which HOST="" and the
path variables contradict; state empty handling per row instead.
- MCP_SANDBOX_PORT / MCP_APP_ORIGIN_PORT accept 0; only CLIENT_PORT
must be fixed.
- NO_COLOR: an empty value counts as unset.
- MCP_INSPECTOR_SECRET_FILE default is ~/.mcp-inspector/secrets.json,
beside the storage directory, not inside it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TRJ64MnDTg1TpzCTEV9Xva
Signed-off-by: cliffhall <cliff@futurescale.com>
Every variable that changes runtime behavior now lives on one page,
docs/environment-variables.md: which client reads it, its default, and
its effect. It covers three variables that were undocumented
(MCP_LOG_FILE, MCP_INSPECTOR_LOG_DIR, LOG_LEVEL), the secret-store
variables previously only in the Docker guide, and the Node TLS
variables that answer #1936 (a self-signed https://localhost server).
The README docs table, the migration guide, docker.md and the four
client READMEs link to it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TRJ64MnDTg1TpzCTEV9Xva
Signed-off-by: cliffhall <cliff@futurescale.com>
Copilot review round 5 on #2100.
- The store bounded entry COUNT only, and the route admits 8Mi code units per
document with a one-hour TTL — ~256Mi retainable on documents a server
under test chooses the size of. Added a 64Mi retained-size budget evicted
oldest-first alongside the count bound, with a running total kept in step
with the map through a single `drop` seam so it cannot drift.
- The isolation claim was wrong about cookies. A separate port makes a
separate ORIGIN, so DOM access, localStorage, sessionStorage and IndexedDB
are isolated — but cookies are keyed by host and path, ignoring port, so an
app served here shares the 127.0.0.1 jar with the Inspector and every other
loopback service. Not a hole in the Inspector's own auth (the API token is
a header plus a window global and sessionStorage, none of them cookies) and
not closable without a distinct host this listener cannot mint, so it is
stated plainly in both the module header and clients/web/README.md rather
than left as a claim that is false for one of the three surfaces it names.
- Removed a shell-escaping artifact I left in the migration guide.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>
Copilot review round 4 on #2100. All three findings are the same error:
clients/web/README.md documents the limitation correctly, and every
port-forwarding blurb then said the opposite.
An unpublished/unforwarded port is NOT the opaque-origin fallback case. The
backend's listener binds fine inside the container, so publication succeeds
and the browser is handed a URL it cannot reach — the frame stays blank,
with no console warning, because a cross-origin navigation failure is not
observable from the page. The fallback and its warning cover the failures
the BACKEND can see: no listener, a port that never bound, an older backend,
a network error.
Corrected in the root README's Docker blurb and the migration guide's
third-port recipe. The migration guide's troubleshooting entry had the wrong
symptom for the same reason — a missing forward produces a blank frame, not
an app whose requests are rejected — so it now leads with that and keeps the
rejected-requests case beside it as the neighbouring symptom, since the two
have opposite causes and opposite console output.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>
Copilot review round 3 on #2100.
- MCP_APP_ORIGIN_PORT could equal CLIENT_PORT or MCP_SANDBOX_PORT. The
app-origin listener starts BEFORE the web server binds, so that is not a
race it loses — it wins the port and the Inspector dies with EADDRINUSE.
`CLIENT_PORT=6278` was a valid config before this feature existed. It now
resolves to a dynamic port with a warning: of the three listeners this is
the only one that can move, and refusing to boot would cost the user the
whole Inspector over a feature they may not be using.
- The proxy's same-origin refusal covered only its own origin. An app served
from the INSPECTOR's origin is no safer: same-origin with the top document
means direct access to window.top, its DOM and its storage, and the
cross-origin frame in between buys nothing. Both trusted origins are now
refused before allow-same-origin is granted.
- Replaced the `as unknown as number` on `server.address()` with a real
narrowing of the string/null members of its return type.
- MCP_APP_ORIGIN_PORT added to the v1→v2 migration guide's env table, its
Docker recipe, and a troubleshooting entry for the symptom this actually
produces (the app renders, but its own backend rejects `Origin: null`).
- clients/web/README.md now states which failure is outside the fallback
guarantee — a published document the browser cannot reach — and why there
is no honest signal to fall back on. Docs and code no longer disagree.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>
- The `retriedDynamic` latch test never made the retry fail: a real `listen(0)`
always succeeds, so it produced one EADDRINUSE and passed with the latch
deleted. Mock `node:http` so every listen fails, asserting exactly two listen
attempts and a settled result. Verified by mutation: removing the latch now
hangs the test instead of passing it.
- The migration guide's Docker notes still described a dynamic sandbox port and
told readers to pin a custom one, contradicting the new fixed 6275 two
sections later.
- Narrowed "or any container" in the troubleshooting entry, which overstated the
scope and contradicted the PR's own scope note. It now names the IPv4-forwarder
case and explicitly excludes the official image and a plain loopback -p.
Signed-off-by: cliffhall <cliff@futurescale.com>
Two defaults that each break the Inspector inside a container.
#1951 — the web UI never loads in a VS Code dev container. `HOST` defaulted
to the NAME `localhost`, and `server.listen(port, host)` resolves a name
through `dns.lookup` and binds the SINGLE address it gets back. Since Node 17
the default result order is `verbatim`, so on a glibc Linux host — whose
/etc/hosts maps localhost to both 127.0.0.1 and ::1 — that is `::1`. The
server bound IPv6 loopback only and refused every IPv4 client, including the
dev container port forwarder. It presents as an endless spinner rather than a
connection error because the forwarder accepts on the host side before failing
to connect inward. Default to the ADDRESS 127.0.0.1 instead; an explicit
HOST=localhost is still honored as typed.
#2008 — the Apps tab is unreachable in any container. The MCP Apps sandbox
listened on an OS-assigned port, so it changed every run and could never be
named in a devcontainer `forwardPorts`, a `docker run -p`, or a tunnel. Default
it to a fixed 6275, mirroring CLIENT_PORT's fixed 6274, and retry once on an
OS-assigned port (loudly) if it is taken — the collision a dynamic default
never had.
Verified in the reporter's exact image
(mcr.microsoft.com/devcontainers/typescript-node:4-24-trixie): both listeners
come up on 127.0.0.1 and answer 200 on 6274 and 6275/sandbox.
Also EXPOSE 6275 and set MCP_SANDBOX_PORT in the image, and document both
defaults in the web README, the migration guide, and the root README's Docker
section.
Signed-off-by: cliffhall <cliff@futurescale.com>
- The v1 recipe published on 127.0.0.1 and the v2 one silently dropped
that. Docker's -p binds host interfaces independently of the
container's HOST, and a no-Origin request skips the allow-list
(core/mcp/remote/node/server.ts:241), so the token is the only guard on
a process-spawning backend. Restore the loopback prefix on both
recipes and say why.
- MCP_PROXY_AUTH_TOKEN is not removed: web-server-config.ts:329 still
falls back to it. Call it a deprecated fallback rather than a rename,
and distinguish it from the query param, which has no fallback
(App.tsx getAuthToken reads only the new name).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SFXDQBEjvjCEBhmYkmw79a
- The "nothing combines with an ad-hoc target" rule has a web exception:
run-web.ts:130 exempts `--transport stdio`, so web ignores it rather
than rejecting. Only cli/tui reject every `--transport`.
- mcp-server-configuration.md still said a leading-dash argument cannot
reach a stdio server under --cli, the opposite of what the migration
guide now says. The parser puts every pre-`--` token in targetArgs, so
the guide is right; corrected the older section to match.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SFXDQBEjvjCEBhmYkmw79a
- `--` under --cli: everything before the separator IS forwarded to the
target, flags included (cli.ts:536-541), so "no way to pass a
leading-dash argument" was wrong. Show the correct placement instead
of sending users to a catalog file.
- Stdout: v2's emitResult appends "\n" where v1's awaitableLog wrote the
JSON with no terminator, so the output is not byte-identical.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SFXDQBEjvjCEBhmYkmw79a
- Sandbox port: the Apps tab needs a second, dynamic listener, so
"no second port" was wrong for Docker/remote deployments. Qualify the
architecture section, add a pinned-port Docker recipe, and add a
troubleshooting entry.
- Node floor: npm only warns EBADENGINE unless engine-strict is set, so
npx does not refuse to run on an older Node.
- v1 default list: the web UI persisted its list in localStorage; only
the on-disk default catalog is new.
- The v1→v2 --server example needs --cli (and a --method) to select an
entry; note there is no one-entry web equivalent.
- New behavior change #4: an ambiguous URL path (neither /mcp nor /sse)
now errors instead of falling back to SSE.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SFXDQBEjvjCEBhmYkmw79a
Closes#1822
Adds docs/v1-to-v2-migration.md — the map for users arriving from v1:
- CLI flag mapping (every v1 flag survives; lists what v2 adds)
- `--config` vs `--catalog` semantics with before/after examples
- Node engine bump (>=22.7.5 → >=22.19.0)
- what no longer ships (the three sub-packages; v2 is one tarball)
- the three behavior changes most likely to bite: exit code 5 on a
failing tool call, target-must-come-first under --cli, and the
reversed `--` separator
- env-var mapping (MCP_PROXY_AUTH_TOKEN → MCP_INSPECTOR_API_TOKEN,
MCP_PROXY_FULL_ADDRESS removed, SERVER_PORT repurposed), the v1 UI
config settings, web query params, and Docker
Linked from the root README (banner + docs list), the CLI README, and
docs/mcp-server-configuration.md; AGENTS.md's docs/ tree entry updated.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SW1p8E2uiyyLx4RKwrwSrt
