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>
Address round-1 review nits on apps.ts:
- readUiMeta now accepts `unknown` and narrows internally, removing the
three `as WithUiMeta` casts at its call sites (readability win).
- Add a comment documenting that the content-block-then-result precedence
for `_meta.ui` is intentional (posture lives on the content block; no
shallow merge).
- Add a TODO to switch to the named McpUiToolMeta/McpUiResourceMeta types
once the upstream extensionless re-export is fixed for NodeNext.
Coverage: apps.ts 100% lines / 97.05% branch / 100% funcs — clears the gate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S3fTN8H3R8YV4yUGvZjYnX
Add a machine-readable summary of an MCP App's UI metadata: the AppInfo
interface plus extractAppInfo(), which merges a tool's _meta.ui
(resourceUri, visibility) with the linked UI resource's _meta.ui (csp,
permissions, domain, prefersBorder, mimeType). Content-block matching is
exact-URI first, then a lowercase + trailing-slash normalized match, then
a single-block fallback since resources/read returns the requested
resource by definition. Shared plumbing for the programmatic-review path
(CLI --app-info, integration tests) without rendering the app.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S3fTN8H3R8YV4yUGvZjYnX
* feat(apps): add isAppTool helper in core (#1260)
Adds @modelcontextprotocol/ext-apps as a dependency (root + clients/web)
and a thin core/mcp/apps.ts wrapper exposing:
- getAppResourceUri(tool): re-export of getToolUiResourceUri so all
Inspector clients consume the same nested/flat _meta resolution.
- isAppTool(tool): boolean predicate built on top of getAppResourceUri.
Both surface the underlying ext-apps throw on a malformed _meta.ui.resourceUri
(string that does not start with "ui://") rather than swallowing it — server
bugs should be visible.
Tests cover nested format, deprecated flat format, nested-wins precedence,
missing _meta, and the invalid-URI throw.
Refs #1260
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* test(apps): address PR #1272 review feedback
- core/mcp/apps.ts: convert getAppResourceUri from a typed const re-export to
a function declaration so its export style matches isAppTool. Behavior is
unchanged.
- core/mcp/apps.ts: document the filter-iteration implication on isAppTool —
callers using tools.filter(isAppTool) will halt on a server-malformed URI.
- apps.test.ts: add the symmetric isAppTool false-case for `_meta.ui` present
without `resourceUri`.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
