feat(core): custom-method support (3-arg setRequestHandler + request schema overload)#1974
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🦋 Changeset detectedLatest commit: 5568303 The changes in this PR will be included in the next version bump. This PR includes changesets to release 7 packages
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LGTM, some potential nits, not blocking.
KKonstantinov
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…t()/mcpReq.send schema overloads for custom methods
…ation as 2nd arg; export StandardSchemaV1; fix example headers
…g for discoverability (KKonstantinov)
…ce during async result validation); add core to changeset; setNotificationHandler JSDoc notes 2nd arg
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…nstead of ProtocolError(InternalError)
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…and §5 scenario table
…RequestHandler/removeNotificationHandler/assertCanSetRequestHandler
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…nySchema removed in #1974)
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…dardSchemaV1 (post-#1974)
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Custom (non-spec) method support: typed registration and sending. Replaces the #1891 / #1916 / #1917 chain with a single overload-based design.
Protocolstays private (dispatcher RFC handles framework subclassing).setRequestHandler/setNotificationHandlergain a 3-arg form:(method, { params, result? }, handler).paramsis any Standard Schema; the handler receives the parsed params object._metais stripped before validation (available asctx.mcpReq._meta). Supplyingresulttypes the handler's return value.request()andctx.mcpReq.sendgain a(req, resultSchema)overload for typed custom-method results.Spec-method calls are unchanged (2-arg
setRequestHandler, 1-argrequest()). 2 overloads each onsetRequestHandler/setNotificationHandler/request.Motivation and Context
v2-main's
setRequestHandler/request()only accept the closedRequestMethod/NotificationMethodunions, so vendor-prefixed methods (which the spec permits) cannot be registered or sent. The #1891/#1916/#1917 stack solved this with both v1-compat ZodSchema overloads and aProtocolSpec<SpecT>typed-vocabulary mechanism; this PR is the minimal cut: one new overload per method. See discussion on #1891.How Has This Been Tested?
packages/core/test/shared/customMethods.test.ts(9 tests): 3-arg registration, params validation,_metastrip, typed return viaresult,request()schema overload,mcpReq.sendschema overload. typecheck/lint/build/docs/test:all clean locally.Breaking Changes
None to v2-main. v1's
setRequestHandler(ZodSchema, h)form is not restored here; it is mechanically codemod-able to the 3-arg form (#1950).Types of changes
Checklist
Additional context
Alternative to #1891 / #1916 / #1917 (which stay open for comparison). Internally widens
_requestWithSchemaand the TaskManager send-chain from Zod-onlyAnySchematoStandardSchemaV1; Zod schemas implementStandardSchemaV1so existing internal callers are unchanged.Protocolis intentionally not exported in this PR. A separate dispatcher RFC (gist) covers the framework-subclassing use case; until that lands,Protocolstays internal-only.Includes a
_wrapHandlerprotected hook so subclass per-method validation (tools/callinServer,elicitation/create/sampling/createMessageinClient) does not require redeclaringsetRequestHandler's overload set. The hook runs for both registration paths; validation behavior is unchanged.