Version Packages (beta) (modelcontextprotocol#2484)

github-actions[bot] · web-flow · commit e81758caed29 · 2026-07-13T18:38:22.000+01:00
Co-authored-by: github-actions[bot] &lt;41898282+github-actions[bot]@users.noreply.github.com&gt;
diff --git a/.changeset/pre.json b/.changeset/pre.json
@@ -29,19 +29,25 @@
     "calltoolresult-content-default",
     "cjs-ajv-validator-subpath",
     "cjs-support-v2-packages",
+    "codemod-fixed-group",
     "codemod-iterations-5",
     "codemod-versions-from-manifests",
     "content-type-media-type-validation",
     "cross-bundle-error-instanceof",
     "examples-protected-wiring",
     "initialize-session-hygiene",
+    "lazy-ajv-engine",
+    "lazy-era-wire-schemas",
     "malformed-resource-uri-invalid-params",
     "post-dispatch-32021-http-400",
     "probe-window-handler-restore",
+    "response-cache-document-codec",
+    "schemas-source-home",
     "silent-validators-wave",
     "standard-header-ows",
     "standard-schema-elicitation",
     "web-standard-bearer-auth",
-    "web-standard-oauth-metadata"
+    "web-standard-oauth-metadata",
+    "workerd-schema-preload"
   ]
 }
diff --git a/packages/client/CHANGELOG.md b/packages/client/CHANGELOG.md
@@ -1,5 +1,26 @@
 # @modelcontextprotocol/client
 
+## 2.0.0-beta.4
+
+### Minor Changes
+
+- [#2468](https://github.com/modelcontextprotocol/typescript-sdk/pull/2468) [`5db6e38`](https://github.com/modelcontextprotocol/typescript-sdk/commit/5db6e38f2bdeb5052f608121e9a2679ff8742af2) Thanks [@felixweinberger](https://github.com/felixweinberger)! - The response cache now stores results as JSON-serialized documents (serialize on write, parse on read) instead of live object graphs isolated with `structuredClone`. Same mutation isolation, but no dependency on the `structuredClone` global — whose absence (jest+jsdom, Node < 17) previously made every cache write throw into the store-error swallow, silently disabling caching and output-schema lookups for the session. A value without a JSON representation now fails the write loudly to the error sink, and an undecodable document in an external store is reported, dropped, and read as a miss.
+
+    Migration for custom `ResponseCacheStore` implementations: `CacheEntry.value` (and the `set()` entry value) is now `string` — persist and return it verbatim, `JSON.parse` to inspect. Entries persisted by a previous SDK version fail decode once (reported, dropped) and are rewritten on the next fetch.
+
+- [#2477](https://github.com/modelcontextprotocol/typescript-sdk/pull/2477) [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Move the schema source modules (spec schemas, OAuth schemas, protocol constants) into `@modelcontextprotocol/core` and resolve them from there as a regular runtime dependency instead of bundling a private copy into each package. An application importing more than one of the packages now evaluates a single shared schema graph with shared object identity. `@modelcontextprotocol/core` gains a `./internal` subpath (SDK-internal contract; may change in any release) and the four packages now version together.
+
+- [#2483](https://github.com/modelcontextprotocol/typescript-sdk/pull/2483) [`3f07a32`](https://github.com/modelcontextprotocol/typescript-sdk/commit/3f07a325c6741b2374ce2255846dfa0c25f74d03) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Add `preloadSchemas()`, an explicit opt-in to eager wire-schema construction, and call it automatically in the Cloudflare Workers builds. The wire schemas are built lazily by default, which is the right trade on process-per-invocation runtimes — but on isolate platforms that bill request CPU while module evaluation runs during isolate warm-up, laziness moves construction into the first request each fresh isolate serves. Calling `preloadSchemas()` at module scope (it is synchronous and idempotent) moves that one-time cost back to module evaluation; the packages' workerd export condition now does this automatically, while the Node and browser builds stay lazy. The server package gains a dedicated browser shim for this (its `browser` condition previously reused the workerd shim), so browser bundles keep lazy construction.
+
+### Patch Changes
+
+- [#2458](https://github.com/modelcontextprotocol/typescript-sdk/pull/2458) [`7c49b47`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7c49b47fb3a58b51cec8fd0b337f656515f1a2b7) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Construct the default Ajv validation engine lazily on first validation. Creating a `Client` or `Server` no longer pays the ajv + ajv-formats instantiation cost at startup when no JSON Schema validation ever runs.
+
+- [#2476](https://github.com/modelcontextprotocol/typescript-sdk/pull/2476) [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Build protocol-revision wire schemas lazily on first validation instead of at import. Each revision's schema set is now constructed by a module-level memoized factory, so importing the client or server package no longer pays the construction cost of both frozen wire-schema graphs up front. Method membership in the revision registries stays static, the schemas themselves are unchanged, and registry lookups keep returning reference-identical schema objects.
+
+- Updated dependencies [[`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4)]:
+    - @modelcontextprotocol/core@2.0.0-beta.4
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/client/package.json b/packages/client/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/client",
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Model Context Protocol implementation for TypeScript - Client package",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/codemod/CHANGELOG.md b/packages/codemod/CHANGELOG.md
@@ -1,5 +1,11 @@
 # @modelcontextprotocol/codemod
 
+## 2.0.0-beta.4
+
+### Patch Changes
+
+- [#2486](https://github.com/modelcontextprotocol/typescript-sdk/pull/2486) [`ee8267a`](https://github.com/modelcontextprotocol/typescript-sdk/commit/ee8267af4a55efda3cebdb35a1ebb1d797e4235d) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Version the codemod together with the core SDK packages, matching the migration guide's shared-version guarantee.
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/codemod/package.json b/packages/codemod/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/codemod",
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Codemod to migrate MCP TypeScript SDK code from v1 to v2",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/core-internal/CHANGELOG.md b/packages/core-internal/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/core-internal
 
+## 2.0.0-beta.3
+
+### Patch Changes
+
+- Updated dependencies [[`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4)]:
+    - @modelcontextprotocol/core@2.0.0-beta.4
+
 ## 2.0.0-beta.2
 
 ### Minor Changes
diff --git a/packages/core-internal/package.json b/packages/core-internal/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/core-internal",
     "private": true,
-    "version": "2.0.0-beta.2",
+    "version": "2.0.0-beta.3",
     "description": "Model Context Protocol implementation for TypeScript - Core package",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/core/CHANGELOG.md b/packages/core/CHANGELOG.md
@@ -1,5 +1,11 @@
 # @modelcontextprotocol/core
 
+## 2.0.0-beta.4
+
+### Minor Changes
+
+- [#2477](https://github.com/modelcontextprotocol/typescript-sdk/pull/2477) [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Move the schema source modules (spec schemas, OAuth schemas, protocol constants) into `@modelcontextprotocol/core` and resolve them from there as a regular runtime dependency instead of bundling a private copy into each package. An application importing more than one of the packages now evaluates a single shared schema graph with shared object identity. `@modelcontextprotocol/core` gains a `./internal` subpath (SDK-internal contract; may change in any release) and the four packages now version together.
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/core/package.json b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/core",
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Model Context Protocol for TypeScript — public Zod schemas (spec + OAuth/OpenID)",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/middleware/express/CHANGELOG.md b/packages/middleware/express/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/express
 
+## 2.0.0-beta.4
+
+### Patch Changes
+
+- Updated dependencies [[`7c49b47`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7c49b47fb3a58b51cec8fd0b337f656515f1a2b7), [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989), [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4), [`3f07a32`](https://github.com/modelcontextprotocol/typescript-sdk/commit/3f07a325c6741b2374ce2255846dfa0c25f74d03)]:
+    - @modelcontextprotocol/server@2.0.0-beta.4
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/middleware/express/package.json b/packages/middleware/express/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/express",
     "private": false,
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Express adapters for the Model Context Protocol TypeScript server SDK - Express middleware",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/middleware/fastify/CHANGELOG.md b/packages/middleware/fastify/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/fastify
 
+## 2.0.0-beta.4
+
+### Patch Changes
+
+- Updated dependencies [[`7c49b47`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7c49b47fb3a58b51cec8fd0b337f656515f1a2b7), [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989), [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4), [`3f07a32`](https://github.com/modelcontextprotocol/typescript-sdk/commit/3f07a325c6741b2374ce2255846dfa0c25f74d03)]:
+    - @modelcontextprotocol/server@2.0.0-beta.4
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/middleware/fastify/package.json b/packages/middleware/fastify/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/fastify",
     "private": false,
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Fastify adapters for the Model Context Protocol TypeScript server SDK - Fastify middleware",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/middleware/hono/CHANGELOG.md b/packages/middleware/hono/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/hono
 
+## 2.0.0-beta.4
+
+### Patch Changes
+
+- Updated dependencies [[`7c49b47`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7c49b47fb3a58b51cec8fd0b337f656515f1a2b7), [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989), [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4), [`3f07a32`](https://github.com/modelcontextprotocol/typescript-sdk/commit/3f07a325c6741b2374ce2255846dfa0c25f74d03)]:
+    - @modelcontextprotocol/server@2.0.0-beta.4
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/middleware/hono/package.json b/packages/middleware/hono/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/hono",
     "private": false,
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Hono adapters for the Model Context Protocol TypeScript server SDK - Hono middleware",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/middleware/node/CHANGELOG.md b/packages/middleware/node/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/node
 
+## 2.0.0-beta.4
+
+### Patch Changes
+
+- Updated dependencies [[`7c49b47`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7c49b47fb3a58b51cec8fd0b337f656515f1a2b7), [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989), [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4), [`3f07a32`](https://github.com/modelcontextprotocol/typescript-sdk/commit/3f07a325c6741b2374ce2255846dfa0c25f74d03)]:
+    - @modelcontextprotocol/server@2.0.0-beta.4
+
 ## 2.0.0-beta.3
 
 ### Patch Changes
diff --git a/packages/middleware/node/package.json b/packages/middleware/node/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/node",
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Model Context Protocol implementation for TypeScript - Node.js middleware",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/packages/server-legacy/CHANGELOG.md b/packages/server-legacy/CHANGELOG.md
@@ -1,5 +1,18 @@
 # @modelcontextprotocol/server-legacy
 
+## 2.0.0-beta.4
+
+### Minor Changes
+
+- [#2477](https://github.com/modelcontextprotocol/typescript-sdk/pull/2477) [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Move the schema source modules (spec schemas, OAuth schemas, protocol constants) into `@modelcontextprotocol/core` and resolve them from there as a regular runtime dependency instead of bundling a private copy into each package. An application importing more than one of the packages now evaluates a single shared schema graph with shared object identity. `@modelcontextprotocol/core` gains a `./internal` subpath (SDK-internal contract; may change in any release) and the four packages now version together.
+
+### Patch Changes
+
+- [#2476](https://github.com/modelcontextprotocol/typescript-sdk/pull/2476) [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Build protocol-revision wire schemas lazily on first validation instead of at import. Each revision's schema set is now constructed by a module-level memoized factory, so importing the client or server package no longer pays the construction cost of both frozen wire-schema graphs up front. Method membership in the revision registries stays static, the schemas themselves are unchanged, and registry lookups keep returning reference-identical schema objects.
+
+- Updated dependencies [[`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4)]:
+    - @modelcontextprotocol/core@2.0.0-beta.4
+
 ## 2.0.0-beta.2
 
 ### Patch Changes
diff --git a/packages/server-legacy/package.json b/packages/server-legacy/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/server-legacy",
     "private": false,
-    "version": "2.0.0-beta.2",
+    "version": "2.0.0-beta.4",
     "description": "Frozen v1 SSE transport and OAuth Authorization Server helpers for the Model Context Protocol TypeScript SDK. Deprecated; use StreamableHTTP and a dedicated OAuth server in production.",
     "deprecated": "This package is a frozen copy of v1's SSE transport and OAuth Authorization Server helpers for migration purposes only. Use StreamableHTTP from @modelcontextprotocol/server and a dedicated OAuth server in production. Will not receive new features.",
     "license": "MIT",
diff --git a/packages/server/CHANGELOG.md b/packages/server/CHANGELOG.md
@@ -1,5 +1,22 @@
 # @modelcontextprotocol/server
 
+## 2.0.0-beta.4
+
+### Minor Changes
+
+- [#2477](https://github.com/modelcontextprotocol/typescript-sdk/pull/2477) [`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Move the schema source modules (spec schemas, OAuth schemas, protocol constants) into `@modelcontextprotocol/core` and resolve them from there as a regular runtime dependency instead of bundling a private copy into each package. An application importing more than one of the packages now evaluates a single shared schema graph with shared object identity. `@modelcontextprotocol/core` gains a `./internal` subpath (SDK-internal contract; may change in any release) and the four packages now version together.
+
+- [#2483](https://github.com/modelcontextprotocol/typescript-sdk/pull/2483) [`3f07a32`](https://github.com/modelcontextprotocol/typescript-sdk/commit/3f07a325c6741b2374ce2255846dfa0c25f74d03) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Add `preloadSchemas()`, an explicit opt-in to eager wire-schema construction, and call it automatically in the Cloudflare Workers builds. The wire schemas are built lazily by default, which is the right trade on process-per-invocation runtimes — but on isolate platforms that bill request CPU while module evaluation runs during isolate warm-up, laziness moves construction into the first request each fresh isolate serves. Calling `preloadSchemas()` at module scope (it is synchronous and idempotent) moves that one-time cost back to module evaluation; the packages' workerd export condition now does this automatically, while the Node and browser builds stay lazy. The server package gains a dedicated browser shim for this (its `browser` condition previously reused the workerd shim), so browser bundles keep lazy construction.
+
+### Patch Changes
+
+- [#2458](https://github.com/modelcontextprotocol/typescript-sdk/pull/2458) [`7c49b47`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7c49b47fb3a58b51cec8fd0b337f656515f1a2b7) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Construct the default Ajv validation engine lazily on first validation. Creating a `Client` or `Server` no longer pays the ajv + ajv-formats instantiation cost at startup when no JSON Schema validation ever runs.
+
+- [#2476](https://github.com/modelcontextprotocol/typescript-sdk/pull/2476) [`e0a0ab7`](https://github.com/modelcontextprotocol/typescript-sdk/commit/e0a0ab74d9baed74572c9f435313fb6daef1b989) Thanks [@felixweinberger](https://github.com/felixweinberger)! - Build protocol-revision wire schemas lazily on first validation instead of at import. Each revision's schema set is now constructed by a module-level memoized factory, so importing the client or server package no longer pays the construction cost of both frozen wire-schema graphs up front. Method membership in the revision registries stays static, the schemas themselves are unchanged, and registry lookups keep returning reference-identical schema objects.
+
+- Updated dependencies [[`8e1d2e9`](https://github.com/modelcontextprotocol/typescript-sdk/commit/8e1d2e92b1720d2520122b3a5f20ea084edaf3c4)]:
+    - @modelcontextprotocol/core@2.0.0-beta.4
+
 ## 2.0.0-beta.3
 
 ### Minor Changes
diff --git a/packages/server/package.json b/packages/server/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/server",
-    "version": "2.0.0-beta.3",
+    "version": "2.0.0-beta.4",
     "description": "Model Context Protocol implementation for TypeScript - Server package",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "@modelcontextprotocol/client",`
`3`		`- "version": "2.0.0-beta.3",`
	`3`	`+ "version": "2.0.0-beta.4",`
`4`	`4`	`"description": "Model Context Protocol implementation for TypeScript - Client package",`
`5`	`5`	`"license": "MIT",`
`6`	`6`	`"author": "Anthropic, PBC (https://anthropic.com)",`
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "@modelcontextprotocol/codemod",`
`3`		`- "version": "2.0.0-beta.3",`
	`3`	`+ "version": "2.0.0-beta.4",`
`4`	`4`	`"description": "Codemod to migrate MCP TypeScript SDK code from v1 to v2",`
`5`	`5`	`"license": "MIT",`
`6`	`6`	`"author": "Anthropic, PBC (https://anthropic.com)",`
Original file line number	Diff line number	Diff line change
`@@ -1,7 +1,7 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "@modelcontextprotocol/core-internal",`
`3`	`3`	`"private": true,`
`4`		`- "version": "2.0.0-beta.2",`
	`4`	`+ "version": "2.0.0-beta.3",`
`5`	`5`	`"description": "Model Context Protocol implementation for TypeScript - Core package",`
`6`	`6`	`"license": "MIT",`
`7`	`7`	`"author": "Anthropic, PBC (https://anthropic.com)",`
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "@modelcontextprotocol/core",`
`3`		`- "version": "2.0.0-beta.3",`
	`3`	`+ "version": "2.0.0-beta.4",`
`4`	`4`	`"description": "Model Context Protocol for TypeScript — public Zod schemas (spec + OAuth/OpenID)",`
`5`	`5`	`"license": "MIT",`
`6`	`6`	`"author": "Anthropic, PBC (https://anthropic.com)",`