modelcontextprotocol/typescript-sdk
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The MCP TypeScript SDK is the official TypeScript implementation for building Model Context Protocol servers and clients for Node.js, Bun, and Deno. It provides server and client libraries plus optional middleware adapters to wire MCP into runtimes like Node.js HTTP, Express, and Hono. It is useful if you want to expose or consume MCP tools, resources, and prompts from a TypeScript app.
Project status
- Actively maintained, with very recent upstream activity (last upstream push on 2026-07-29) and multiple SDK updates dated 2026-07-27, indicating the project is actively evolving rather than in maintenance mode.
- Update cadence appears fast in the short term, with several related packages moving together within a couple of days (suggesting a coordinated v2 beta rollout aligned to the MCP 2026-07-28 spec revision).
AI summary generated
Recent updates
@modelcontextprotocol/fastify@2.0.0
This release is the first beta of the TypeScript SDK v2, adding support for the MCP 2026-07-28 specification revision. It also ships CommonJS builds alongside ESM, updating package export maps so require() consumers can load the SDK successfully, while keeping public import paths unchanged.
BreakingFeatures@modelcontextprotocol/server-legacy@2.0.0
This release is part of the first beta of SDK v2 for the MCP 2026-07-28 specification revision, and it includes packaging and runtime initialization changes intended to reduce import-time overhead. It also moves shared schema resources into @modelcontextprotocol/core so applications importing multiple MCP packages share a single schema graph.
BreakingFeatures@modelcontextprotocol/express@2.0.0
express@2.0.0 is the first beta release of the MCP SDK v2 for the MCP 2026-07-28 specification revision, and it aligns Express with new runtime-neutral server middleware. It also ships dual ESM and CommonJS builds, adds runtime-neutral Bearer auth support, and introduces OAuth discovery serving built on web-standard fetch(request) handlers.
BreakingFeatures@modelcontextprotocol/server@2.0.0
Model Context Protocol server@2.0.0 updates the TypeScript SDK/server to align with the final MCP 2026-07-28 wire revision and related runtime behaviors. The most important upgrade impact is a breaking change to how server identity is represented in Discover responses (moved from the body into response _meta), plus stricter HTTP Content-Type handling and a corrected HTTP status mapping for certain capability errors.
BreakingFeatures@modelcontextprotocol/core@2.0.0
modelcontextprotocol/core@2.0.0 aligns the TypeScript SDK wire format to the finalized MCP 2026-07-28 revision, including moving server identity from the DiscoverResult body into response _meta and making Discover request envelope clientInfo optional. It also changes how schema modules are packaged, so applications importing multiple MCP packages share a single schema graph. Additionally, it restores v1-style parsing tolerance for legacy tools/call results missing CallToolResult.content, and ships CommonJS builds alongside ESM.
BreakingFeatures@modelcontextprotocol/codemod@2.0.0
modelcontextprotocol/codemod v2.0.0 is a beta codemod release aligned with the TypeScript SDK v2 migration, including support for the MCP 2026-07-28 specification revision. Alongside migration improvements (including correct Protocol and mergeCapabilities import rewriting, and better version stamping), the release notes also include SDK packaging changes (CommonJS builds) and a server-side Bearer auth enhancement for additional runtime hosts.
BreakingFeatures@modelcontextprotocol/client@2.0.0
Release @modelcontextprotocol/client@2.0.0 moves MCP v2 to the stable v2 line aligned with the 2026-07-28 spec revision, including wire-format and negotiation behavior updates. It also introduces API surface adjustments (Protocol and mergeCapabilities exports), validation and schema construction optimizations (lazy Ajv and lazy wire-schema construction), and more correct/typed error handling during version negotiation.
BreakingFeatures@modelcontextprotocol/node@2.0.0
This release is the first beta of the TypeScript SDK v2 for the MCP 2026-07-28 specification revision. It adds CommonJS compatibility alongside ESM and introduces stricter JSON Content-Type validation, which can affect custom transport or server code that previously relied on looser checks.
BreakingFeatures@modelcontextprotocol/hono@2.0.0
This release is the first beta of the @modelcontextprotocol/hono SDK v2, adding support for the MCP 2026-07-28 specification revision (see migration guides). It also ships CommonJS builds alongside ESM, and tightens request handling for JSON POSTs by properly parsing Content-Type and rejecting non-JSON media types with 415.
BreakingFeatures1.30.0
Release 1.30.0 focuses on server robustness improvements and interoperability fixes, including better Zod error handling, stricter Content-Type parsing, and more reliable SSE keep-alive behavior. It also adds a stdio buffer limit and updates CI publishing to use OIDC trusted publishing.
Security@modelcontextprotocol/node@2.0.0-beta.5
This beta release (@modelcontextprotocol/node@2.0.0-beta.5) contains only dependency updates, with no new functionality or behavioral changes documented in the release notes. It bumps the bundled/related @modelcontextprotocol/server dependency to the corresponding @2.0.0-beta.5 version.
@modelcontextprotocol/core@2.0.0-beta.5
This beta release aligns the TypeScript MCP wire behavior with the final 2026 spec revision. It changes where server identity information is carried in discovery results and makes the request envelope clientInfo optional, which fixes prior handshake and validation mismatches.
BreakingFeatures@modelcontextprotocol/server@2.0.0-beta.5
This beta aligns the TypeScript MCP wire format with the final 2026 spec revision, moving server identity information into the discover result `_meta` and making `clientInfo` in the request envelope optional. It also restores v1-compatible imports by exporting `Protocol` and `mergeCapabilities` from the `@modelcontextprotocol/client` and `@modelcontextprotocol/server` package roots, with codemod updates to rewrite affected imports.
BreakingFeatures@modelcontextprotocol/fastify@2.0.0-beta.5
This is a patch release of @modelcontextprotocol/fastify beta.5 that primarily updates its dependency on @modelcontextprotocol/server to version 2.0.0-beta.5. No user-facing API, behavior changes, or fixes are explicitly called out in the release notes.
@modelcontextprotocol/express@2.0.0-beta.5
This is a beta.5 patch release of @modelcontextprotocol/express. The release notes only mention dependency updates, specifically aligning with @modelcontextprotocol/server@2.0.0-beta.5.
@modelcontextprotocol/hono@2.0.0-beta.5
modelcontextprotocol/hono@2.0.0-beta.5 is a dependency-only patch release. It updates the underlying @modelcontextprotocol/server dependency to version 2.0.0-beta.5, without any new features or behavioral changes explicitly documented in the release notes.
@modelcontextprotocol/server-legacy@2.0.0-beta.5
This beta patch release updates the server-legacy package to depend on @modelcontextprotocol/core version 2.0.0-beta.5. No direct behavioral or API changes are described in the release notes beyond the dependency bump.
@modelcontextprotocol/client@2.0.0-beta.5
This beta release updates the client to align fully with the 2026-07-28 wire revision, including moving server identity to result `_meta` and demoting per-request `clientInfo` to SHOULD. It also adds support for cached era verdicts via `ConnectOptions.prior`, improves stdio version negotiation by probing on a disposable sibling process, and restores v1 compatibility by exporting `Protocol` and `mergeCapabilities` from the package roots.
BreakingFeatures@modelcontextprotocol/codemod@2.0.0-beta.5
This codemod release restores v1-compatible imports for MCP consumers by exporting the `Protocol` base class and `mergeCapabilities` from the `@modelcontextprotocol/client` and `@modelcontextprotocol/server` package roots. It also updates codemod rewriting so `Protocol` and `mergeCapabilities` imports are rewritten to the appropriate client or server root (instead of being dropped with an action-required marker).
@modelcontextprotocol/express@2.0.0-beta.4
This beta patch release updates the express package dependency on @modelcontextprotocol/server to version 2.0.0-beta.4. Release notes do not list any express-specific API, behavior, or bug fix changes beyond the dependency bump.