Version Packages (beta)

[github-actions]

This PR was opened by the Changesets release GitHub action. When you're ready to do a release, you can merge this and publish to npm yourself or setup this action to publish automatically. If you're not ready to do a release yet, that's fine, whenever you add more changesets to main, this PR will be updated.

⚠️⚠️⚠️⚠️⚠️⚠️

main is currently in pre mode so this branch has prereleases rather than normal releases. If you want to exit prereleases, run changeset pre exit on main.

⚠️⚠️⚠️⚠️⚠️⚠️

Releases

@modelcontextprotocol/client@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.

@modelcontextprotocol/codemod@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.

• #2412 ef120b2 Thanks @felixweinberger! - v1-to-v2 migration fixes from continued real-world migrations (codemod iterations 5).

@modelcontextprotocol/core@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.

@modelcontextprotocol/express@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.
• Updated dependencies [f172626, 3c7ddaf]:
  • @modelcontextprotocol/server@2.0.0-beta.2

@modelcontextprotocol/fastify@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.
• Updated dependencies [f172626, 3c7ddaf]:
  • @modelcontextprotocol/server@2.0.0-beta.2

@modelcontextprotocol/hono@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.
• Updated dependencies [f172626, 3c7ddaf]:
  • @modelcontextprotocol/server@2.0.0-beta.2

@modelcontextprotocol/node@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.
• Updated dependencies [f172626, 3c7ddaf]:
  • @modelcontextprotocol/server@2.0.0-beta.2

@modelcontextprotocol/server@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.

• #2399 3c7ddaf Thanks @felixweinberger! - Return HTTP 400 for a MissingRequiredClientCapabilityError (-32021) produced after dispatch. The spec mandates 400 Bad Request for this error with no condition on where it arose, but only the pre-dispatch capability gate honored that; the post-handler emission — the input_required gate rejecting an embedded request whose required capability the caller did not declare — surfaced in-band on HTTP 200. The JSON-RPC error body is unchanged, every other error code (including a handler relaying a downstream peer's -32020/-32022) keeps the origin-keyed in-band behavior, and the mapping only applies while the response is uncommitted: an exchange that already streamed — or one hosted with responseMode: 'sse', which opens its stream at dispatch end — keeps its committed 200 and carries the error in-stream.

@modelcontextprotocol/server-legacy@2.0.0-beta.2

Patch Changes

• #2405 f172626 Thanks @mattzcarey! - Ship CommonJS builds alongside ESM. Each package now emits both .mjs/.d.mts
  and .cjs/.d.cts (via tsdown format: ['esm', 'cjs']), and its exports map
  adds a require condition so require('@modelcontextprotocol/…') works from
  CommonJS consumers. Output extensions are normalized across all packages
  (@modelcontextprotocol/core moves from .js/.d.ts to .mjs/.d.mts); the
  public import paths are unchanged.

@modelcontextprotocol/core-internal@2.0.0-beta.1

Patch Changes

• #2399 3c7ddaf Thanks @felixweinberger! - Return HTTP 400 for a MissingRequiredClientCapabilityError (-32021) produced after dispatch. The spec mandates 400 Bad Request for this error with no condition on where it arose, but only the pre-dispatch capability gate honored that; the post-handler emission — the input_required gate rejecting an embedded request whose required capability the caller did not declare — surfaced in-band on HTTP 200. The JSON-RPC error body is unchanged, every other error code (including a handler relaying a downstream peer's -32020/-32022) keeps the origin-keyed in-band behavior, and the mapping only applies while the response is uncommitted: an exchange that already streamed — or one hosted with responseMode: 'sse', which opens its stream at dispatch end — keeps its committed 200 and carries the error in-stream.

[pkg-pr-new]

Open in StackBlitz

@modelcontextprotocol/client

npm i https://pkg.pr.new/@modelcontextprotocol/client@2416

@modelcontextprotocol/codemod

npm i https://pkg.pr.new/@modelcontextprotocol/codemod@2416

@modelcontextprotocol/core

npm i https://pkg.pr.new/@modelcontextprotocol/core@2416

@modelcontextprotocol/server

npm i https://pkg.pr.new/@modelcontextprotocol/server@2416

@modelcontextprotocol/server-legacy

npm i https://pkg.pr.new/@modelcontextprotocol/server-legacy@2416

@modelcontextprotocol/express

npm i https://pkg.pr.new/@modelcontextprotocol/express@2416

@modelcontextprotocol/fastify

npm i https://pkg.pr.new/@modelcontextprotocol/fastify@2416

@modelcontextprotocol/hono

npm i https://pkg.pr.new/@modelcontextprotocol/hono@2416

@modelcontextprotocol/node

npm i https://pkg.pr.new/@modelcontextprotocol/node@2416

commit: de501ea

[claude]

LGTM — machine-generated changesets release PR; version bumps and changelog entries are consistent with the three changesets it consumes.

Extended reasoning...

Overview

This is the auto-generated "Version Packages (beta)" PR from the changesets action. It touches only package.json version fields, CHANGELOG.md files, and .changeset/pre.json across the workspace packages. The three newly-consumed changesets (cjs-support-v2-packages, codemod-iterations-5, post-dispatch-32021-http-400) exist in .changeset/ and correspond exactly to the entries added to pre.json and the changelog text, all of which was authored and reviewed in the underlying PRs (#2405, #2412, #2399). Version bumps are consistent patch bumps in pre-mode (beta.1 → beta.2; core-internal beta.0 → beta.1), including the dependent-bump entries on the middleware packages.

Security risks

None. No source code, auth, transport, or CI logic changes — only version metadata and generated changelog prose.

Level of scrutiny

Low for correctness: the content is mechanically generated by changeset version and matches the changesets on main. The one human decision this PR represents is release timing — merging it triggers the publish flow — which remains entirely with the maintainers regardless of this shadow approval.

Other factors

No bugs were found by the bug hunting system, there are no outstanding reviewer comments, and the changelog entries reproduce the changeset text from already-merged PRs verbatim, so there is nothing new to review beyond confirming the mechanical consistency above.