modelcontextprotocol · felixweinberger · Jun 25, 2026 · Jun 25, 2026 · Jun 25, 2026 · Jun 25, 2026
@@ -1,5 +1,5 @@
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-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
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 Abort in-flight request handlers when the connection closes. Previously, request handlers would continue running after the transport disconnected, wasting resources and preventing proper cleanup. Also fixes `InMemoryTransport.close()` firing `onclose` twice on the initiating side.
@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/core': minor
+---
+
+Add `@modelcontextprotocol/core`: the public home for the MCP specification and OAuth/OpenID Zod schemas. It bundles the SDK's internal schema definitions and re-exports only the `*Schema` values, so consumers can validate protocol payloads (`<TypeName>Schema.parse(value)` / `.safeParse(value)`) without depending on a package's internal barrel. Alongside the spec schemas it also re-exports the auth schemas v1 exposed from `@modelcontextprotocol/sdk/shared/auth.js` (e.g. `OAuthTokensSchema`, `OAuthMetadataSchema`, `IdJagTokenExchangeResponseSchema`). Spec types, error classes, enums, and guards continue to live on `@modelcontextprotocol/server` and `@modelcontextprotocol/client`.
@@ -1,5 +1,5 @@
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-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
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 Add missing `size` field to `ResourceSchema` to match the MCP specification
@@ -1,5 +1,5 @@
 ---
-"@modelcontextprotocol/core": minor
+"@modelcontextprotocol/core-internal": minor
 "@modelcontextprotocol/client": minor
 ---
 

@@ -1,6 +1,6 @@
 ---
 '@modelcontextprotocol/client': minor
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
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 Add opt-in protocol version negotiation on `ClientOptions.versionNegotiation`. The default is unchanged: without the option (or with `mode: 'legacy'`) the client performs today's 2025 connect sequence byte-identically. `mode: 'auto'` probes the server with `server/discover` at

@@ -1,6 +1,6 @@
 ---
 '@modelcontextprotocol/client': minor
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 ---
 
 Dynamic Client Registration hygiene for the 2026-07-28 authorization requirements (SEP-837, SEP-2207). New `resolveClientMetadata(provider)` reads `provider.clientMetadata` and applies the spec defaults — `application_type` derived from the redirect URIs (loopback or custom scheme → `'native'`, otherwise `'web'`), `grant_types: ['authorization_code', 'refresh_token']` when omitted — and `auth()` feeds the resolved document to DCR only (scope selection still reads the raw consumer-supplied `clientMetadata` so statically-registered/CIMD clients are not pushed into `offline_access` + `prompt=consent`); consumer-set values are never overwritten. DCR rejection now throws the new `RegistrationRejectedError` carrying the HTTP status, raw body, and submitted metadata — **breaking for direct `registerClient()` callers**: rejection no longer throws `OAuthError`, so update `instanceof` checks. `OAuthClientMetadata` gains a typed `application_type?: string` field (expected `'native'` / `'web'`; tolerant on parse). `OAuthErrorCode` adds `InvalidRedirectUri`. The token-exchange, refresh, and Cross-App Access (`requestJwtAuthorizationGrant` / `exchangeJwtAuthGrant`) paths now throw the new `InsecureTokenEndpointError` for a non-`https:` token endpoint (`localhost` / `127.0.0.1` / `::1` exempt), and `auth()` surfaces it on the refresh branch instead of silently re-authorizing.
@@ -1,5 +1,5 @@
 ---
-"@modelcontextprotocol/core": minor
+"@modelcontextprotocol/core-internal": minor
 "@modelcontextprotocol/client": minor
 ---
 

@@ -1,6 +1,6 @@
 ---
 '@modelcontextprotocol/client': minor
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 ---
 
 Add the public surface for the 2026-07-28 authorization requirements. New `AuthOptions` type names the `auth()` options object and adds `iss` and `skipIssuerMetadataValidation` fields. `OAuthClientProvider.clientInformation()` / `.saveClientInformation()` / `.tokens()` / `.saveTokens()` accept an optional `OAuthClientInformationContext` carrying the authorization server's `issuer` so providers can key persisted credentials per authorization server. New `StoredOAuthTokens` / `StoredOAuthClientInformation` aliases add an `issuer` stamp field on top of the wire types (kept off the wire schemas so an authorization server cannot populate it) and become the parameter/return types of the credential methods. New `OAuthClientFlowError` base class in `authErrors.ts` for the flow-specific error classes that follow. All changes are additive — existing `OAuthClientProvider` implementations compile unchanged; the new fields are inert until the behavior changes that follow wire them up.
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 '@modelcontextprotocol/server': patch
 ---
 

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/server': minor
 ---
 

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': minor
 ---
 

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': minor
 '@modelcontextprotocol/server': minor
 ---

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': major
+'@modelcontextprotocol/core-internal': major
 '@modelcontextprotocol/client': major
 '@modelcontextprotocol/server': major
 ---

@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/codemod': minor
+---
+
+Route v1 `@modelcontextprotocol/sdk/types.js` schema imports to the new `@modelcontextprotocol/core` package. The `*Schema` Zod constants now migrate as a behavior-preserving import-path swap — `<Name>Schema.parse(value)` / `.safeParse(value)` keep working — while spec types, error classes, enums, and guards continue to resolve to `@modelcontextprotocol/client` / `@modelcontextprotocol/server` by context. A single `import { CallToolResult, CallToolResultSchema } from '.../types.js'` is split accordingly. The v1 OAuth/OpenID `*Schema` constants imported from `@modelcontextprotocol/sdk/shared/auth.js` are routed to `@modelcontextprotocol/core` the same way (their auth TYPES keep resolving to `client` / `server`). The previous `specSchemaAccess` transform (which rewrote `.parse()` into `specTypeSchemas.X['~standard'].validate(...)`) is removed.
@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/codemod': patch
+---
+
+Infer client/server project type from source for v1 projects. A project being migrated still declares the single v1 `@modelcontextprotocol/sdk` dependency, so detecting the project type from `package.json` came back "unknown" and every file importing only shared protocol symbols defaulted to `@modelcontextprotocol/server` with an action-required warning. The codemod now scans the source for quoted `@modelcontextprotocol/sdk/client/…` and `…/server/…` import specifiers to infer the type (both → "both", one → that side, neither → "unknown"), routing shared symbols to the installed package and replacing the spurious warnings with at most an info note for genuinely ambiguous "both" projects.
@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/codemod': patch
+---
+
+Map the task request/notification schemas to their v2 method strings in the handler-registration transform. `setRequestHandler(GetTaskRequestSchema, …)`, `setNotificationHandler(TaskStatusNotificationSchema, …)`, and the other task handlers (`tasks/get`, `tasks/result`, `tasks/list`, `tasks/cancel`, `notifications/tasks/status`) now rewrite to the v2 two-argument method-string form instead of falling through to the generic "use the 3-argument form" manual-migration diagnostic.
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': minor
 '@modelcontextprotocol/server': minor
 ---

@@ -1,6 +1,6 @@
 ---
 '@modelcontextprotocol/client': minor
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 ---
 
 Per-request `_meta` envelope auto-emission on modern-era connections: once a client negotiates a 2026-07-28+ protocol revision (via `versionNegotiation: { mode: 'auto' }` or `{ pin }`), it automatically attaches the reserved protocol-version / client-info / client-capabilities

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 '@modelcontextprotocol/client': patch
 '@modelcontextprotocol/server': patch
 ---

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 ---
 
 Consolidate per-request cleanup in `_requestWithSchema` into a single `.finally()` block. This fixes an abort signal listener leak (listeners accumulated when a caller reused one `AbortSignal` across requests) and two cases where `_responseHandlers` entries leaked on send-failure paths.
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
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 Add explicit `| undefined` to optional properties on the `Transport` interface and `TransportSendOptions` (`onclose`, `onerror`, `onmessage`, `sessionId`, `setProtocolVersion`, `setSupportedProtocolVersions`, `onresumptiontoken`).

@@ -1,5 +1,5 @@
 ---
-"@modelcontextprotocol/core": minor
+"@modelcontextprotocol/core-internal": minor
 "@modelcontextprotocol/server": major
 ---
 

@@ -2,7 +2,7 @@
 '@modelcontextprotocol/node': patch
 '@modelcontextprotocol/test-integration': patch
 '@modelcontextprotocol/server': patch
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 ---
 
 remove deprecated .tool, .prompt, .resource method signatures
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': major
+'@modelcontextprotocol/core-internal': major
 '@modelcontextprotocol/client': major
 '@modelcontextprotocol/server': major
 ---

@@ -0,0 +1,6 @@
+---
+'@modelcontextprotocol/client': minor
+'@modelcontextprotocol/server': minor
+---
+
+Add the v2 `IdJagTokenExchangeResponse` type to the public API and register its schema as an MCP spec type. `IdJagTokenExchangeResponse` is now exported from `@modelcontextprotocol/client` and `@modelcontextprotocol/server`, `'IdJagTokenExchangeResponse'` joins the `SpecTypeName` union, and `isSpecType.IdJagTokenExchangeResponse(value)` / `specTypeSchemas.IdJagTokenExchangeResponse` validate it by name — matching how the OAuth/OpenID auth schemas are already exposed. The Zod schema itself, `IdJagTokenExchangeResponseSchema`, is available from `@modelcontextprotocol/core`.
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': minor
 '@modelcontextprotocol/server': minor
 ---

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': minor
 ---
 

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/server': minor
 ---
 

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 '@modelcontextprotocol/server': patch
 ---
 

@@ -9,60 +9,100 @@
     "@modelcontextprotocol/examples-client-quickstart": "2.0.0-alpha.0",
     "@modelcontextprotocol/examples-server-quickstart": "2.0.0-alpha.0",
     "@modelcontextprotocol/client": "2.0.0-alpha.0",
-    "@modelcontextprotocol/core": "2.0.0-alpha.0",
+    "@modelcontextprotocol/core-internal": "2.0.0-alpha.0",
     "@modelcontextprotocol/express": "2.0.0-alpha.0",
     "@modelcontextprotocol/fastify": "2.0.0-alpha.0",
     "@modelcontextprotocol/hono": "2.0.0-alpha.0",
     "@modelcontextprotocol/node": "2.0.0-alpha.0",
     "@modelcontextprotocol/server": "2.0.0-alpha.0",
     "@modelcontextprotocol/server-legacy": "2.0.0-alpha.0",
+    "@modelcontextprotocol/core": "2.0.0-alpha.0",
     "@modelcontextprotocol/codemod": "2.0.0-alpha.0",
     "@modelcontextprotocol/test-conformance": "2.0.0-alpha.0",
     "@modelcontextprotocol/test-helpers": "2.0.0-alpha.0",
-    "@modelcontextprotocol/test-integration": "2.0.0-alpha.0"
+    "@modelcontextprotocol/test-integration": "2.0.0-alpha.0",
+    "@modelcontextprotocol/test-e2e": "2.0.0-alpha.0"
   },
   "changesets": [
     "abort-handlers-on-close",
+    "add-consumer-sse-e2e",
+    "add-core-public-package",
+    "add-e2e-test-suite",
     "add-fastify-middleware",
     "add-hono-peer-dep",
     "add-resource-size-field",
+    "add-sdk-http-error",
+    "add-server-legacy-package",
+    "bound-resumability-version-gates",
     "brave-lions-glow",
     "busy-rice-smoke",
     "busy-weeks-hang",
+    "cfworker-out-of-barrel",
+    "codemod-core-routing",
+    "codemod-infer-project-type",
+    "codemod-resolve-legacy-imports",
+    "codemod-streamablehttperror-sdkhttperror",
+    "codemod-task-handler-methods",
+    "custom-methods-minimal",
     "cyan-cycles-pump",
+    "draft-spec-non-sep-conformance",
     "drop-zod-peer-dep",
+    "export-inmemory-transport",
     "expose-auth-server-discovery",
+    "expose-icons-on-tools-and-prompts",
+    "express-resource-server-auth",
     "extract-task-manager",
     "fast-dragons-lead",
     "finish-sdkerror-capability",
     "fix-abort-listener-leak",
+    "fix-conformance-server-leak",
     "fix-oauth-5xx-discovery",
     "fix-onerror-callbacks",
     "fix-server-protocol-version",
     "fix-session-status-codes",
     "fix-stdio-epipe-crash",
     "fix-stdio-windows-hide",
+    "fix-streamable-close-reentrant",
     "fix-streamable-http-error-response",
     "fix-task-session-isolation",
     "fix-transport-exact-optional-property-types",
     "fix-unknown-tool-protocol-error",
+    "fix-validate-client-metadata-url",
     "funky-baths-attack",
+    "gentle-planets-rest",
     "heavy-walls-swim",
+    "hono-peer-optional",
+    "idjag-spec-type-export",
+    "legacy-module-resolution-types",
     "oauth-error-http200",
+    "odd-forks-enjoy",
     "quick-islands-occur",
     "reconnection-scheduler",
+    "register-rawshape-compat",
     "remove-websocket-transport",
     "respect-capability-negotiation",
+    "restore-task-wire-types",
     "rich-hounds-report",
     "schema-object-type-for-unions",
+    "sep-2577-deprecate-runtime-apis",
+    "sep-2663-tasks-removal",
+    "sep-414-trace-context-meta-keys",
     "shy-times-learn",
+    "spec-reference-types-2026-07-28",
+    "spec-type-schema",
     "spotty-cats-tickle",
+    "stdio-max-buffer-size",
     "stdio-skip-non-json",
+    "stdio-subpath-export",
     "support-standard-json-schema",
     "tame-camels-greet",
     "tender-snails-fold",
     "token-provider-composable-auth",
     "twelve-dodos-taste",
-    "use-scopes-supported-in-dcr"
+    "use-scopes-supported-in-dcr",
+    "workerd-shim-vendors-cfworker",
+    "wraphandler-hook",
+    "zod-json-schema-compat",
+    "zod-jsonschema-fallback"
   ]
 }
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 ---
 
 `Protocol.request()` now rejects with `SdkError(RequestTimeout, reason)` when called with an already-aborted signal, matching in-flight aborts. Previously the raw `signal.reason` was thrown.
@@ -4,7 +4,7 @@
 '@modelcontextprotocol/node': patch
 '@modelcontextprotocol/client': patch
 '@modelcontextprotocol/server': patch
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 ---
 
 remove npm references, use pnpm
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 '@modelcontextprotocol/server': patch
 ---
 

@@ -1,5 +1,5 @@
 ---
-"@modelcontextprotocol/core": minor
+"@modelcontextprotocol/core-internal": minor
 "@modelcontextprotocol/server": major
 "@modelcontextprotocol/client": minor
 ---

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/server': minor
 '@modelcontextprotocol/client': minor
 ---

@@ -4,7 +4,7 @@
 '@modelcontextprotocol/node': patch
 '@modelcontextprotocol/client': patch
 '@modelcontextprotocol/server': patch
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 ---
 
 clean up package manager usage, all pnpm
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 ---
 
 Ensure `standardSchemaToJsonSchema` emits `type: "object"` at the root, fixing discriminated-union tool/prompt schemas that previously produced `{oneOf: [...]}` without the MCP-required top-level type. Also throws a clear error when given an explicitly non-object schema (e.g. `z.string()`). Fixes #1643.
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': major
 '@modelcontextprotocol/server': major
 ---

@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/client': minor
 ---
 

@@ -1,10 +1,10 @@
 ---
-'@modelcontextprotocol/core': minor
+'@modelcontextprotocol/core-internal': minor
 '@modelcontextprotocol/server': minor
 ---
 
 SEP-2243 standard-header server-side validation (protocol revision 2026-07-28). On the modern (2026-07-28) serving path, `createMcpHandler` now enforces the required `Mcp-Method` and `Mcp-Name` standard request headers in addition to the existing `MCP-Protocol-Version` and `Mcp-Method` cross-checks: a modern request without an `Mcp-Method` header, a `tools/call` / `prompts/get` / `resources/read` request without an `Mcp-Name` header, an `Mcp-Name` header carrying an invalid `=?base64?…?=` sentinel, and an `Mcp-Name` header whose (decoded) value disagrees with the body's `params.name` / `params.uri` are all rejected with `400 Bad Request` and JSON-RPC `-32020` (`HeaderMismatch`). The 2025-era serving paths are unchanged.
 
 New public surface:
 
-- `@modelcontextprotocol/core`: `validateStandardRequestHeaders` (function), `MCP_NAME_HEADER_SOURCE` (const), the `mcpNameHeader` field on `InboundHttpRequest`, and the `'standard-header-validation'` member of `InboundValidationRung` (with `client-capabilities` / `param-header-validation` renumbered).
+- `@modelcontextprotocol/server`: the `mcpNameHeader` field on `InboundHttpRequest`, and the `'standard-header-validation'` member of `InboundValidationRung` (with `client-capabilities` / `param-header-validation` renumbered).
@@ -1,5 +1,5 @@
 ---
-'@modelcontextprotocol/core': patch
+'@modelcontextprotocol/core-internal': patch
 '@modelcontextprotocol/server': patch
 '@modelcontextprotocol/client': patch
 ---