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[DO NOT MERGE] Port to SDK v2 (extension() registrar / composition) - #612
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felixweinberger wants to merge 28 commits into
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[DO NOT MERGE] Port to SDK v2 (extension() registrar / composition)#612felixweinberger wants to merge 28 commits into
felixweinberger wants to merge 28 commits into
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…ompat pass-through schemas
…ansport on v2 Transport
…ssignment)
Preserves all public methods and on* handlers. Removed: 5 assert*Capability
no-op overrides, inherited Protocol surface. Wire renames: notifications/message
-> ui/log; oncalltool/onlisttools now on ui/{call-view-tool,list-view-tools}.Standard MCP proxying via server.setRequestHandler. ui/initialize handler kept
for v1-iframe wire compat. callTool/listTools wire renamed to ui/{call-view-tool,
list-view-tools}.…nHandle casts; ctx type params; exclude docs/; gen-schemas path
… tsc clean npx tsc --noEmit -> 0 errors npm run build -> see commit body
…pulls child_process) npm run build -> see body
…ed pre-connect (v1 parity)
…oolUiResourceUri validation (v1 parity)
…express,node}; restore test tsconfig includes
…mulate, onclose shim, onupdatemodelcontext return type, getToolUiResourceUri error message
…opped Protocol surface
…basic-host typo+v1 schema usage
… unported pdf-server suite The pdf-server example's server.test.ts (~77 tests) needs deeper v2 porting beyond the SDK migration scope. SDK tests + pdf-annotations.test.ts (no SDK coupling) all pass.
…ypescript-sdk#1871)
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April 13, 2026 15:39
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76b3ba7Compare- spec.types.ts: import RequestId from @modelcontextprotocol/client (already public)
- app.ts/app-bridge.ts: replace pass-through *Schema shims with z.custom<T>(v => isSpecType('T', v))
- generate-schemas.ts: emit isSpecType-backed z.custom for external SDK types instead of importing from sdk-compat
- delete src/sdk-compat.ts
Friction surfaced: ExtensionHandle.setRequestHandler/sendRequest accept AnySchema (Zod-only),
so specTypeSchema()'s StandardSchemaV1 return cannot be passed directly. Wrapped via
z.custom(isSpecType) instead. #1868 should widen the param type to StandardSchemaV1 | AnySchema.felixweinbergerforce-pushed
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2fe270fCompare…pt-sdk#1846 StandardSchemaV1 widening) generated/schema.ts keeps z.custom(isSpecType()) since it composes into Zod chains; specTypeSchema() is used at the ExtensionHandle boundary where the SDK now accepts StandardSchemaV1. app-bridge event-map params type widened ZodType -> StandardSchemaV1. app.ts no longer imports zod.
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60e9d69Compare- AppBridge dual-listens on legacy notifications/message → loggingmessage event - bridge.callTool/listTools throw descriptive error if iframe is v1 (instead of MethodNotFound) - Unskip ping test (Server.ping() is public; skip reason was wrong) - Document on*-setter replace-semantics with explicit test - BREAKING.md: v1↔v2 interop section, host-first upgrade guidance
…mappings
- Remove tsconfig excludes for *.examples.ts(x) and docs/ — all now typecheck
- Port companion files to v2 API (app.ui.sendRequest, client.callTool, z.object wraps)
- typedoc externalSymbolLinkMappings for @modelcontextprotocol/{client,server}
- Fix raw-shape inputSchema and Schema.shape→Schema across 9 example servers
- 25/25 examples now build; typedoc warnings 11→0….registerTool) All 33 fails fixed: v2 registerTool requires StandardSchema (raw shapes lack ~standard.validate). Also extra.signal→extra.mcpReq.signal, drop stale v1 import. test:full now 277/2/0 (was 197/1/33). e2e API tests pass; browser tests need playwright install (env, not v2 break).
felixweinberger added a commit
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Apr 15, 2026
- import paths sdk/* → @modelcontextprotocol/{client,server}
- events.ts: ProtocolWithEvents extends Protocol (concrete), v1-schema-shim setRequestHandler
- request/notification call-shape transforms (perl)
- drop assert*Capability overrides (Protocol no longer abstract)
- server/index.ts copied from #612 port
- tsconfig: exclude *.examples.ts, docs/ (same as #612)
NOT YET: *Schema imports → specTypeSchema(), request() visibility, ~225 tsc errors remain6 tasks
felixweinberger
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Apr 15, 2026
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Closing in favor of #614 (concrete |
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DO NOT MERGE — proof-of-concept port to SDK v2. CI is expected to fail (
package.jsondepends on localfile:/tmp/*.tgzSDK builds that combine unpublished typescript-sdk changes).Review guide — file map, reading order, what to skip (105 files but ~90 are mechanical)
105 files changed, but ~90 of them are mechanical. This guide maps what to read vs skim.
If you have 10 minutes
BREAKING.md— the public-surface delta. This is the contract.src/app.ts—class Appdeclaration (search forclass App extends EventDispatcher). The whole composition pattern is visible in the first ~50 lines of the class body:readonly client: Client,readonly ui: ExtensionHandle<...>, thenui.setRequestHandler(...)calls in the constructor. Note: nozodimport — embedded spec types validated viaspecTypeSchema()from the SDK.src/app-bridge.ts— same, search forclass AppBridge extends EventDispatcher. Notereadonly server: Serverand theserver.setRequestHandler('tools/call', ...)proxy wiring alongsideui.*forui/*methods.src/app-bridge.test.ts— most of the file is unchanged. That's the point.File map
Read carefully (~6 files, the actual design)
BREAKING.mdsrc/app.tsAppcomposesClient+ExtensionHandle. Noassert*Capabilityoverrides. No zod import —specTypeSchema('CallToolResult')etc. passed directly.src/app-bridge.tsAppBridgecomposesServer+ExtensionHandle. Standardtools/calletc. viasetRequestHandler.src/events.tsProtocolWithEvents(subclass of SDKProtocol) → standaloneEventDispatcher<EventMap>. No SDK coupling.src/message-transport.tsPostMessageTransporton the v2Transportinterface.src/server/index.tsregisterAppTool/registerAppResourceon v2McpServer.Skim (mechanical, verify pattern then move on)
src/spec.types.ts,src/types.tsinterface McpUi*Capabilities→type(forJSONObjectconstraint).src/generated/{schema.ts,schema.json,schema.test.ts}z.custom<T>(isSpecType('T', v))for embedded SDK types. Don't review line-by-line.src/app-bridge.test.tssrc/react/useApp.tsx,src/server/index.test.ts,src/*.examples.tsexamples/**package.jsondeps,main.tsimport path (/stdiosubpath),server.tsv2McpServershape. Read one (examples/basic-server-react/) to see the pattern.docs/,scripts/generate-schemas.tsisSpecType()for SDK types.package.json,build.bun.ts,tsconfig.json, lockfiletsconfigexclusions for unported*.examples.ts.Recommended reading order (by commit)
25 commits, intentionally staged. Read bottom-up in groups:
1. Setup (skim):
231251a6deps swap,b50315b1types/schemas,a9713e3dEventDispatcher + transport.2. The core rewrite (read):
25da6658App,a1f1f016AppBridge,a5378733react/server.3. Compile fixes (skim):
ea3f4af5..a97206ca.4. v1 parity fixes (read commit messages):
87fee346,f7490c6b,47f4cdf3,be67283e— each is a behavior the test suite caught.5. Tests + examples (skim):
7e8ae100,cce8436b,570781e0,9998758b,4298d34a,b845fd7c.6. Upstream-fix follow-through (skim):
953a5d81/4e26407d(#1871),76b3ba7a/stdioimport.7. Validator integration (read):
c8bc2649eliminatessdk-compat.tsviaisSpecType();60e9d690passesspecTypeSchema()directly toExtensionHandleafter #1846's StandardSchemaV1 widen.Questions to evaluate
BREAKING.md's "Removed inherited member" table against what consumers actually use.ui/*↔ standard-method split clean? Inapp-bridge.ts, find whereui.setRequestHandler(...)andserver.setRequestHandler('tools/call', ...)coexist.specTypeSchema()the right validator API?app.tspasses it directly toExtensionHandle— no Zod at the consumer.generated/schema.tsusesz.custom(isSpecType())because that file is Zod-composed.AppBridgekeeps aui/initializehandler for v1-iframe back-compat. Right choice vs. clean break?Known gaps (intentional, documented)
npm run test:fullincludesexamples/pdf-server/server.test.ts(~33 fails) — heavy example, deeper port out of scope.tsconfig.jsonexcludessrc/**/*.examples.ts(x)anddocs/— companion JSDoc snippets use removed surface.package.jsonpoints atfile:/tmp/*.tgz.Depends on:
specTypeSchema()for runtime validation of any spec type)Motivation and Context
App/AppBridgemove from subclassingProtocolto composingClient/Server+ExtensionHandleper the SEP-1865 role assignment. SeeBREAKING.mdfor the full surface delta. 73/88 of the v1app-bridge.test.tstests pass unmodified against the rewrite (final: 85 pass / 1 skip / 0 fail).How Has This Been Tested?
Locally against an SDK build with the dependencies above:
npm run build,npm test(197 pass / 1 skip / 0 fail), andbasic-server-react/basic-server-vanillajs/quickstart/basic-hostexample builds all green.npm run test:fullretains the unportedexamples/pdf-serversuite.Breaking Changes
Yes — see
BREAKING.md. Peer dep moves from@modelcontextprotocol/sdk@^1to@modelcontextprotocol/{client,server}@^2.Types of changes
Checklist
Additional context
This PR is the artifact for reviewing the v2 shape. Once the SDK dependencies publish to
@alpha, thefile:deps will be swapped to npm versions and CI will go green.