Addresses review round 4 on #2099 — three posted comments and three suppressed
ones, all valid.
- A rebuilt Response reported `url: ""`, `redirected: false`, and
`type: "default"` even after undici followed a redirect: a fetch-contract
regression visible only to proxy users, and one `core/auth/endpointOverrides.ts`
explicitly guards against by declining to rebuild at all. This adapter has no
such choice — the response arrives from the wrong realm — so it now reinstates
the three with `defineProperty`.
- Normalizing a `Request` input dropped every option the Request itself carried
beyond method/headers/body/signal. Most visibly `redirect`: a
`new Request(url, { redirect: "manual" })` started following redirects instead
of surfacing them. All of them are now carried through, with an explicit
`init` still winning per the fetch contract.
Both are covered by tests driving a real redirect through a real proxy, and
both were confirmed to fail without the fix.
- `@modelcontextprotocol/ext-apps` was added only to the CLI's `external` list.
AGENTS.md requires every root-declared runtime dependency in all three, since
which client reaches it is a function of what `core/` imports rather than of
the client's own code. Added to the web runner and TUI lists too.
- The `BUNDLED_CLIENTS` test compared the hard-coded list against a hard-coded
copy of itself, so a new tsup-bundled client would have left it green while
going unchecked. It now discovers clients from disk (a client is tsup-bundled
iff it ships a tsup config) and compares. Verified it fails when a stub client
is added.
- AGENTS.md's project tree still described `core/mcp/node/` as only the stdio
transport factory; it now carries `proxyFetch.ts` and its role.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JTHVxSu8AUgHRLvo1ntZ8H
Signed-off-by: cliffhall <cliff@futurescale.com>
Corporate-proxy users could not connect to any remote MCP server from v2.
Two independent defects, both reported in #2067.
1. The web and TUI bundles inlined undici. It was declared in the root and
`clients/cli` manifests but named in no client's tsup `external` list, and
tsup auto-externalizes only what the *nearest* manifest declares — so
esbuild inlined 1.05MB of it into `clients/{web,tui}/build/`. undici is
CommonJS, so the emitted chunk's `require("assert")` hit esbuild's ESM
`__require` shim and threw `Dynamic require of "assert" is not supported`.
The rejected `import()` surfaced as "the `undici` package is not available",
telling users to install a package that was already present — and could not
have helped, because the specifier had been rewritten to a relative chunk at
build time.
2. `withProxyDispatcher` injected a *userland* undici `EnvHttpProxyAgent` into
Node's *built-in* fetch. That couples two different copies of undici at the
dispatcher handler interface, which is not stable across majors: Node 22
embeds undici 6, Node 24 embeds 7, Node 26 embeds 8. A userland undici 8
agent handed a built-in undici 7 handler is rejected with
`fetch failed: invalid onRequestStart method`, and the request never leaves
the process. So fixing the bundling alone would only have converted the
web/TUI failure into the CLI's.
Both halves of the pair now come from userland undici — its `fetch` and its
`EnvHttpProxyAgent` — which keeps the handler inside one copy and works
unchanged from the Node 22.19 engine floor through Node 26. Deleting the
wrapper in favor of Node's native `NODE_USE_ENV_PROXY` was not an option:
measured, it is unsupported on 22.19 (the floor) and only lands mid-22.x.
Because undici's `Response` is a different class from `globalThis.Response`,
the proxied fetch re-wraps each response as a genuine global `Response`,
streaming preserved. Without that, `res instanceof Response` is false for
callers that test it — including the SDK's OAuth error formatter, which would
degrade every message to `Raw body: [object Response]`.
The proxy now sits at the bottom of the fetch stack (`environment.fetch` for
the Node clients, and the `createTransportNode` default for the web backend,
its one caller that supplies no `fetchFn`) rather than wrapping the transport's
fetch. Proxying means *substituting* the fetch, not decorating one, so wrapping
a supplied `fetchFn` would discard it; installing it underneath lets
InspectorClient's own wrappers compose over it. A side effect worth having:
OAuth discovery and token requests go through `environment.fetch` too, and were
never proxied before.
Guarding it:
- `undici` is added to all three tsup `external` lists and removed from
`clients/cli/package.json`, so it is root-declared only, per the placement
rule in AGENTS.md. The two installs had already drifted (root 8.5.0 vs cli
8.9.0).
- New `npm run verify:bundle-externals` fails if any package a client declares
external was inlined into that client's bundle anyway. It reads the *built
output*, not the config — those two disagreed for four releases — and derives
what to check from each client's own `external` array, so a newly
externalized package is covered without editing the guard. Verified against
the real pre-fix artifact, which it flags.
- The proxy tests now drive a real forwarding proxy rather than a mock. That
matters: defect 2 was a runtime interface mismatch, which no mock can catch
because no mock ever dispatches.
AGENTS.md's must-not-bundle rule (added by #2082) is extended with why undici
slipped past it, and notes the `node -e` trap — probing the bundled chunk with
`node -e` falsely succeeds, because it exposes a global `require` that
satisfies esbuild's guard.
Closes#2067
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JTHVxSu8AUgHRLvo1ntZ8H
Signed-off-by: cliffhall <cliff@futurescale.com>
#1950 shipped FileSecretStore without cross-process mutual exclusion, by
decision: an earlier revision hand-rolled a `mkdir` election with an owner
stamp, a heartbeat and a stale-takeover, and three consecutive review rounds
found a real race in it. The last one is not closable with what Node exposes
— claiming a stale lock atomically needs compare-and-swap on a directory
entry (`renameat2(RENAME_EXCHANGE)`) — so it was replaced with optimistic
verify-and-retry and the residual documented.
#2082 settles that as "borrow, don't hand-roll". `proper-lockfile` is what
npm itself locks with, and stale-takeover is precisely the problem it has
already solved: it re-stats the lock directory after claiming it and gives
the lock up when the mtime is not the one it wrote, so the loser of a
takeover race releases instead of proceeding.
- core/auth/node/file-lock.ts: `withSecretFileLock`. `realpath: false` so a
file can be locked into existence (the very first `set` has no
`secrets.json`, and the library's default resolves through `fs.realpath`);
a warning in place of the library's `onCompromised`, which throws from a
timer and would take the session down; and a degrade-with-one-warning path
rather than a throw when no lock can be taken — this store exists for boxes
missing the usual mechanism (#1848, #1905) and must not gain a new way to
be unavailable.
- FileSecretStore.mutate holds it across the whole read-modify-write. The
optimistic verify stays underneath and is not redundant: a lock is advisory
between the processes that take it, so the verify covers a writer outside
this codebase and covers the degrade path. The in-process queue stays too,
and gains a second job — proper-lockfile is not reentrant, so serializing
per path keeps ELOCKED meaning "another process".
- absorbFileSecretsIntoKeyring takes the same lock around orphan adoption and
the atomic claim, behind a lock-free `readdir` fast path so the common
startup (keychain available, no file ever written) neither creates a lock
directory nor warns about one it could not create.
proper-lockfile is a root `dependency` per the placement rule, and is named
in all three bundler `external` lists: tsup externalizes what the *client's*
manifest declares, so a root-only CJS package was being inlined into the ESM
bundles, leaving esbuild's `Dynamic require of "path" is not supported` shim
that killed `--cli` at import time. That rule was undocumented; it is now in
AGENTS.md beside the placement rule that creates it, and mirrored into
.github/copilot-instructions.md.
Tests: 7 new in file-lock.test.ts driving a real second process (the existing
suite structurally cannot — `serialize` orders in-process callers before the
lock sees them), plus two for the migration fast path.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JTHVxSu8AUgHRLvo1ntZ8H
Signed-off-by: cliffhall <cliff@futurescale.com>
* chore(web): format-gate the ungated first-party TS/JS (#1778)
Prettier only covered core/ and each client's src/, leaving the web Node
backend (clients/web/server/**), web top-level configs (vite.config.ts,
tsup.runner.config.ts, eslint.config.js, ...), and the root build/verify
tooling (scripts/**/*.mjs) ungated — so their formatting was never checked
by validate/CI. eslint already reached these via `eslint .`, so this is a
prettier-only gap.
- clients/web format/format:check now cover src, server, and top-level
*.{ts,js}, not just src.
- New root format:scripts / format:check:scripts for scripts/**/*.mjs,
folded into the root format and into validate:core.
- Normalized the newly-covered files with prettier --write (pure
formatting; no runtime change).
Closes#1778
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5
* chore: future-proof the scripts format glob (#1778 review)
Widen format:scripts / format:check:scripts from "scripts/**/*.mjs" to
"scripts/**/*.{mjs,js,cjs,ts}" so a future non-.mjs file under scripts/
is auto-gated, matching the future-proof glob style clients/web now uses.
A brace glob is a single pattern, so prettier does not error on the
unmatched branches. Addresses observation #2 from the PR #1788 review.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5
* docs: sync AGENTS.md scripts glob after the widening (#1788 review r2)
d86d8f7 widened the scripts glob to {mjs,js,cjs,ts} and updated the
validate:core bullet, but the format bullet at AGENTS.md:217 still said
scripts/**/*.mjs. Bring it in line so the two mentions agree.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Migrate all three clients + core + test-servers from
@modelcontextprotocol/sdk@1.29 to SDK v2 (2.0.0-beta.4), keeping behavior
identical against legacy (2025-11-25) servers. Foundation for the SDK V2 +
New Spec stack.
Packages
- Split @modelcontextprotocol/sdk -> @modelcontextprotocol/client (Client,
transports, OAuth, error taxonomy, protocol types) + core (Zod schemas);
stdio -> client/stdio, Ajv -> client/validators/ajv. Test-servers ->
@modelcontextprotocol/server (+ server-legacy/sse). Deterministic import
rewrite (schemas -> core, everything else -> client); the codemod misroutes
client code to /server so it was not used for path routing.
- new Client(..., { versionNegotiation: { mode: 'legacy' } }) — nothing
2026-era goes on the wire.
Runtime (core/mcp/inspectorClient.ts)
- Error taxonomy: McpError -> ProtocolError, ErrorCode -> ProtocolErrorCode;
RequestTimeout -> SdkError/SdkErrorCode.
- Handlers take method strings; task methods (tasks/*, notifications/tasks/*)
use the 3-arg custom form (excluded from v2's spec-method set).
- Legacy tasks kept working (per project requirement): requestor tasks re-
implemented over raw client.request + explicit deprecated schemas;
experimental.tasks.callToolStream replaced by a local pollTaskToolCall
async generator (with _progressHandlers revival so task-execution progress
still reaches the caller). Receiver (server-initiated) tasks: the v2 Client
validates a sampling/elicit handler result and rejects the legacy { task }
response with -32602 — installReceiverTaskResponseBypass swaps the wrapped
entry in the private _requestHandlers map for the task-augmented branch so
{ task } reaches the wire (fixes server-initiated sampling-via-task).
- Pagination: list verbs use raw client.request({method}, List*ResultSchema)
for single-page behavior (v2's client.listX() auto-aggregate all pages).
Web / auth / apps
- Rename local JsonSchemaType -> InspectorFormSchema + add toFormSchema()
structural narrowing at the SDK-schema -> form boundary.
- ext-apps still peers on SDK v1: one compat boundary with documented casts
(remove when ext-apps#702 lands a v2 peer).
- OAuth provider saveClientInformation reconciled with v2's
OAuthClientInformationContext; InvalidClientMetadataError re-homed as a
local class (server-legacy/auth is not browser-safe).
- vitest.shared.mts dedupes @modelcontextprotocol/client+core to one copy so
vi.mock intercepts the SUT's import.
Accepted v2 behavior changes (per #1624 / spec §9.2): unknown-tool call
rejects with -32602; cancellation is stream-abort (no guaranteed
notifications/cancelled frame); output-schema strictness restored via the
Inspector's own Ajv check on the default path.
npm run ci green: validate (web 3087 / cli 212 / tui 274 / launcher 5),
coverage (>=90 per-file, all clients), smoke (launcher/cli/web), storybook
(410).
Closes#1624
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Prepare the single `@modelcontextprotocol/inspector` tarball for publishing
and add a script that verifies the real published package end to end.
- Add `scripts/pack-and-verify.mjs` (`npm run pack:verify`): build, `npm pack`,
install the tarball into a clean consumer, and drive the installed
`mcp-inspector` bin (web/cli/tui) — catching "works in --dev, breaks under
npx" packaging/path failures the in-repo smokes miss. Local/release tool
(install needs network), not wired into the fast validate/ci loop.
- Disable source maps in the cli/tui/web-runner tsup configs (~halves the
unpacked payload; runtime doesn't need them).
- Add `clients/web/.npmignore` so `clients/web/build` (prod web-server runner)
ships — npm's packlist was honoring the nested `.gitignore` `build/` entry
over the root "files" allowlist, dropping the runner while `dist/` slipped
through.
- Ship `clients/cli/package.json` and `clients/tui/package.json`: both bundles
read their own package.json at runtime (CLI client identity, TUI header), so
the installed CLI crashed on connect and the installed TUI crashed on launch
without them.
Document the packaging invariants and pack:verify in the launcher README.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BrihGWcrM9JGRyu41nzZYw
Ports the CLI, TUI, and launcher from v1.5 into v2 behind a single
`mcp-inspector` entrypoint (launcher → web/cli/tui). Includes the
`mcp-inspector --web --dev` launcher fix (Vite alias resolution + prod-server
double-start), the root `postinstall` install cascade with simplified CI, and
spec/AGENTS docs (no-workspaces rationale, Development setup).
Closes#1246.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
