* core: refactor serverList.ts object↔Record casts into typed helper (#1690)
Remove the four pre-existing `as unknown as Record<string, unknown>` /
`as unknown as MCPServerConfig` casts in core/mcp/serverList.ts:
- stripInspectorFields: rewrite as clone + `delete` over INSPECTOR_FIELD_KEYS.
Every Inspector-extension key is optional on StoredMCPServer, so the result
is still (a subtype of) MCPServerConfig with no cast.
- oauth-strip in extractSecretsFromStored: `oauth` is optional, so a plain
`delete stripped.oauth` is legal — drop the cast.
- mcpConfigToServerEntries: route the one genuinely-needed widening through a
single documented `toRecord(value: object)` helper. Taking `object` makes the
single `as Record<string, unknown>` legal (no TS2352), so the double cast
disappears from the call site.
Net: zero `as unknown as` in serverList.ts; the one remaining structural cast
lives inside the audited toRecord helper. Behavior-neutral — existing coverage
(79 serverList tests) unchanged; full `npm run ci` passes.
Closes#1690
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5
* core+web+test-servers: eliminate/justify remaining `as unknown as` casts (#1690)
Codebase-wide follow-on to the serverList refactor: audit every `as unknown
as` double cast outside tests and either remove it or ensure it carries a
justifying comment (the review bar is "no *unjustified* double cast").
Removed (widened via a shared helper or narrowed to a single cast):
- Promote the serverList `toRecord(value: object)` widening helper to
core/json/jsonUtils.ts and reuse it at core/mcp/node/config.ts (normalize
loop), core/mcp/remote/node/server.ts (pino level dispatch), and
clients/web/src/App.tsx (window global lookup).
- inspectorClient.rawWireRequest: type the frame as `JSONRPCRequest` and
narrow only `params` with a single structural cast (the SDK's `_meta`-typed
params is what blocked direct assignment).
- toolOutputValidation: SDK `outputSchema` → `JsonSchemaType` is a single cast.
- test-server-fixtures: the optional `task` handle is reachable with a single
cast (target field is optional).
Justified in place (genuinely unavoidable — private SDK internals, partial
interface stubs, third-party/nominal bridges): the inspectorClient private-map
accesses, resourceContext + tokenAuthProvider partial `OAuthClientProvider`
stubs, the ext-apps peer bridge, modern/legacy `_requestHandlers` bypasses,
and the happy-dom `matchMedia` test mock.
Behavior-neutral. Full `npm run ci` passes (validate, ≥90 coverage gate,
smoke, Storybook).
Refs #1690
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5
* address @claude review nits: consistent cast justifications + drop reflow noise (#1690)
- test-servers/src/modern-tasks.ts: add an inline justification above the
`_requestHandlers` double cast, mirroring the sibling in
composable-test-server.ts (was leaning on the function JSDoc only).
- Annotate the partial-`AppBridge` mock double casts in the story fixtures
(AppsScreen ×2, AppRenderer, InspectorView) so no non-test-file double cast
is unjustified.
- inspectorClient.ts: revert unrelated Prettier reflow hunks (protocolVersion,
task-content array, timeout-reject wrap, reconnect guard) so the diff is the
single rawWireRequest cast change only.
Behavior-neutral (comment/format-only). `npm run ci` green apart from a known
flaky redaction test whose assertion collided with a random request id.
Refs #1690
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5
* actually revert the reflow noise this time (#1690)
The reflow reverts in cc187ea were silently undone by a `prettier --write` I
ran on the same file right after, so the four Prettier-only hunks from 6a3afa4a
were still in the diff (caught in re-review). Revert them for real now — and
without re-running Prettier on the file:
- core/mcp/inspectorClient.ts: restore the protocolVersion line, task-content
array, timeout-reject call, and reconnect guard to their origin/v2/main form,
so the file's diff is only the single rawWireRequest cast change.
- test-servers/src/modern-tasks.ts: restore the ModernTaskStatus union to its
one-line form (the leading-`|` reflow was also Prettier churn), leaving only
the new `_requestHandlers` justification comment.
Formatting-only; `npm run validate` green.
Refs #1690
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>
- Run Prettier on the 60 core/ files this PR touched — the deterministic
import rewrite had collapsed multi-line imports and left throws unwrapped;
core/ is in no format gate so it slipped past CI. Now Prettier-clean.
- Default-path output-schema violation now throws
ProtocolError(ProtocolErrorCode.InvalidParams, …) instead of a bare Error,
matching the prior v1 contract (SDK threw a typed McpError with a code) so
downstream `instanceof`/`.code` branching keeps working.
- Document the "assumes serial construction" invariant on pollTaskToolCall's
progress-subscription revival (the `_progressHandlers` new-key heuristic).
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>
* feat(apps): render running MCP Apps end-to-end (#1370)
Wire the v2 Apps screen so clicking Open App actually runs an MCP App.
Previously App.tsx stubbed the three load-bearing pieces (sandbox URL,
bridge factory, action handlers), so the iframe loaded about:blank and
nothing crossed the bridge.
- Add useSandboxUrl hook (core/react) to read sandboxUrl from GET
/api/config and thread it down as sandboxPath; render an "MCP Apps
unavailable" state instead of a blank iframe when absent.
- Add createAppBridgeFactory: builds a host-side ext-apps AppBridge over
the active client's SDK client, reads the tool's UI resource on the
sandbox handshake and pushes it into the proxy, handles openLinks, and
connects a PostMessageTransport.
- AppRenderer: pass the tool to the bridge factory; buffer tool
input/result and release them once the view signals `initialized`
(input before result, latest-wins).
- Move the AppRenderer handle ref to App.tsx so onOpenApp issues
tools/call with the form values and delivers input + result to the
running app via the bridge; onCloseApp tears the bridge/iframe down.
- Stories: themed sandbox placeholder (visible in light/dark), an
echo-bridge running story, and an unavailable story. New unit tests
for the factory, the buffering, useSandboxUrl, and the empty state.
The listChanged indicator badge wiring is tracked separately in #1402.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* fix(apps): make MCP Apps render in dev — single bridge + result passthrough
Two bugs kept apps (e.g. NightRider's MIDI Pattern Editor) stuck on an empty
shell even though the host fetched the resource and called the tool correctly.
1. StrictMode double-mounted the bridge. The dev-only effect setup→cleanup→
setup built TWO host bridges/transports, double-loaded the sandbox, and
raced the app's ui/initialize handshake (it timed out, so `initialized`
never fired and buffered input/result were never flushed). AppRenderer now
defers bridge disposal to a microtask and, when the effect re-runs
synchronously with identical inputs, cancels the disposal and reuses the
live bridge — so a single bridge survives the double-invoke. The pending
input/result buffer is no longer cleared on a transient cleanup.
2. The SDK rejected the server's result. callTool() validates structuredContent
against the tool's outputSchema and throws on a mismatch — but an MCP App is
a passthrough: the host must forward whatever the server returned to the
running view (which legacy hosts render fine). InspectorClient.callTool gains
a `skipOutputValidation` option that routes through client.request() (no
wrapper validation); onOpenApp uses it.
Verified end-to-end against a real app via Playwright: the editor now renders
its grid + pattern data identically to the v1 inspector.
Tests: AppRenderer StrictMode single-bridge/no-dispose case; a get_temp_extra
test-server fixture (returns an extra structuredContent property) with
integration tests covering both the throwing default path and the
skipOutputValidation passthrough.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* feat(apps): warn (toast) when an app's result violates its outputSchema
The skipOutputValidation passthrough keeps schema-mismatched apps rendering,
but that silently hid a real spec problem from server developers. Now the
host still renders, but surfaces the mismatch.
- InspectorClient.callTool runs the SDK's own Ajv output validation on the
skipOutputValidation path NON-fatally and returns the message as
`outputValidationError` on the ToolCallInvocation (and the
toolCallResultChange event); the result is still delivered.
- App.tsx onOpenApp shows a yellow toast when outputValidationError is set,
explaining strict MCP clients may not render the app.
Tests: integration cases asserting outputValidationError is set for a
schema-violating result (get_temp_extra) and unset for a valid one (get_temp).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* feat(apps): summarize output-schema warning in toast + details modal
The previous toast dumped the full (very long) validation error and
overflowed. Now the toast shows a one-line summary with a "View validation
details" link that opens a modal containing the full error in a read-only,
scrollable textarea.
- New OutputValidationModal group component (+ story + tests).
- App.tsx: toast message is a summary + link; clicking it opens the modal
populated with the tool name and the full outputValidationError.
Verified via Playwright against the NightRider MIDI editor: toast is concise,
link opens the modal with the scrollable details.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* refactor(apps): address PR review — theme stability, onError, validation polish
Responds to the automated PR review on #1403.
- Theme toggle no longer rebuilds a running app's bridge. createAppBridgeFactory
reads the resolved theme from the DOM (Mantine's data-mantine-color-scheme) at
bridge-build time instead of capturing isDark in the factory deps, so the
factory identity is stable across theme flips. (#1)
- Wire AppRenderer's onError through AppsScreen -> InspectorView -> App.tsx,
surfacing bridge/runtime failures (no client, late rejection, failed
tools/call) as a red toast instead of a silent blank iframe. (#2)
- Extract validateToolOutput into a pure, unit-tested helper covering the
matching / extra-property / missing-structuredContent / error / bad-schema
cases (the no-structuredContent branch can't be produced via the SDK server,
which rejects it before sending). (#4)
- useSandboxUrl aborts its in-flight fetch on unmount (cancelled flag) to avoid
setState after unmount. (#5)
- Schema-mismatch toast: autoClose:false (details modal is one click away). (note)
- AppRenderer: add a state-machine comment block documenting the bridge
lifecycle refs. (#6)
- inspectorClient: note why the `as CallToolResult` casts are safe. (note)
Tests: AppsScreen onError surface; validateToolOutput unit suite; factory theme
read from DOM. validate + test:storybook green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* docs(apps): clarify theme attribute + useSandboxUrl fetch comments
Re-review follow-ups (non-blocking):
- createAppBridgeFactory: note that Mantine's data-mantine-color-scheme is only
ever light/dark (auto is resolved before paint), so no `auto` branch is needed
and matchMedia only covers an absent attribute.
- useSandboxUrl: correct the doc to say it fetches on mount AND re-fetches on
baseUrl/authToken change (idempotent), not "once on mount".
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Cliff Hall