feat(compat): add @modelcontextprotocol/server/zod-schemas subpath

Re-exports the internal *Schema Zod constants (CallToolRequestSchema,
JSONRPCMessageSchema, etc.) from a deprecated /zod-schemas subpath so v1
code that imported schemas from @modelcontextprotocol/sdk/types.js has a
single drop-in target.

- packages/server/src/zodSchemas.ts: re-export barrel (deprecated module)
- packages/server/package.json: ./zod-schemas exports entry
- packages/server/tsdown.config.ts: build entry + dts path mapping
- packages/server/tsconfig.json: path mappings for core/schemas and the
  self-reference subpath
- packages/core/package.json: internal ./schemas subpath (core is private,
  consumed only by sibling packages)
- compat test asserting the import resolves and schemas parse

The schemas remain an internal implementation detail; their Zod major
version is not covered by semver. Subpath will be removed in v3.

Author: felixweinberger

.changeset/compat-zod-schemas-subpath.md

@@ -0,0 +1,7 @@
+---
+'@modelcontextprotocol/server': patch
+---
+
+Add `@modelcontextprotocol/server/zod-schemas` subpath for v1 compatibility
+
+Re-exports the `*Schema` Zod constants (e.g. `CallToolRequestSchema`, `JSONRPCMessageSchema`) and the `getRequestSchema(method)` / `getResultSchema(method)` / `getNotificationSchema(method)` lookup helpers, so v1 code that imported schemas from `@modelcontextprotocol/sdk/types.js` can be pointed at a single subpath. These are Zod schemas; their TS type may change with internal Zod upgrades. Prefer `specTypeSchema()` for runtime validation.

docs/migration-SKILL.md

@@ -98,7 +98,7 @@ Notes:
 | `StreamableHTTPError`                    | REMOVED (use `SdkError` with `SdkErrorCode.ClientHttp*`) |
 | `WebSocketClientTransport`               | REMOVED (use `StreamableHTTPClientTransport` or `StdioClientTransport`) |
 
-All other **type** symbols from `@modelcontextprotocol/sdk/types.js` retain their original names. **Zod schemas** (e.g., `CallToolResultSchema`, `ListToolsResultSchema`) are no longer part of the public API — they are internal to the SDK. For runtime validation, use type guard functions like `isCallToolResult` instead of `CallToolResultSchema.safeParse()`.
+All other **type** symbols from `@modelcontextprotocol/sdk/types.js` retain their original names. **Zod schemas** (e.g., `CallToolResultSchema`, `ListToolsResultSchema`) are not exported from the package root; for runtime validation prefer type guard functions like `isCallToolResult` or `specTypeSchema()`. For v1 compatibility the schemas are available from the `@modelcontextprotocol/server/zod-schemas` subpath.
 
 ### Error class changes
 

packages/core/package.json

@@ -32,6 +32,10 @@
         "./public": {
             "types": "./src/exports/public/index.ts",
             "import": "./src/exports/public/index.ts"
+        },
+        "./schemas": {
+            "types": "./src/types/schemas.ts",
+            "import": "./src/types/schemas.ts"
         }
     },
     "scripts": {

packages/server/package.json

@@ -24,6 +24,10 @@
             "types": "./dist/index.d.mts",
             "import": "./dist/index.mjs"
         },
+        "./zod-schemas": {
+            "types": "./dist/zodSchemas.d.mts",
+            "import": "./dist/zodSchemas.mjs"
+        },
         "./validators/cf-worker": {
             "types": "./dist/validators/cfWorker.d.mts",
             "import": "./dist/validators/cfWorker.mjs"

packages/server/src/zodSchemas.ts

@@ -0,0 +1,34 @@
+/**
+ * v1-compat re-export of all protocol Zod schemas.
+ *
+ * Prefer {@linkcode specTypeSchema} for runtime validation. These are Zod
+ * schemas; their TS type may change with internal Zod upgrades.
+ *
+ * @deprecated Use `specTypeSchema()` for runtime validation.
+ * @packageDocumentation
+ */
+
+/** @deprecated Use `specTypeSchema()` for runtime validation. */
+export * from '@modelcontextprotocol/core/schemas';
+
+/** @deprecated Use `specTypeSchema()` for runtime validation. */
+export {
+    IdJagTokenExchangeResponseSchema,
+    OAuthClientInformationFullSchema,
+    OAuthClientInformationSchema,
+    OAuthClientMetadataSchema,
+    OAuthClientRegistrationErrorSchema,
+    OAuthErrorResponseSchema,
+    OAuthMetadataSchema,
+    OAuthProtectedResourceMetadataSchema,
+    OAuthTokenRevocationRequestSchema,
+    OAuthTokensSchema,
+    OpenIdProviderDiscoveryMetadataSchema,
+    OpenIdProviderMetadataSchema,
+    OptionalSafeUrlSchema,
+    SafeUrlSchema
+} from '@modelcontextprotocol/core';
+export {
+    /** @deprecated Use {@linkcode JSONRPCErrorResponseSchema}. */
+    JSONRPCErrorResponseSchema as JSONRPCErrorSchema
+} from '@modelcontextprotocol/core/schemas';

packages/server/test/zod-schemas.compat.test.ts

@@ -0,0 +1,23 @@
+import * as z from 'zod/v4';
+
+// Compat: the deprecated `/zod-schemas` subpath re-exports the internal Zod
+// schema constants for v1 source compatibility. This test asserts the import
+// resolves and the values are usable Zod schemas at runtime.
+import { CallToolRequestSchema, JSONRPCMessageSchema, ListToolsResultSchema } from '@modelcontextprotocol/server/zod-schemas';
+
+describe('@modelcontextprotocol/server/zod-schemas (compat subpath)', () => {
+    it('re-exports Zod schema constants from core', () => {
+        expect(CallToolRequestSchema).toBeInstanceOf(z.ZodType);
+        expect(JSONRPCMessageSchema).toBeInstanceOf(z.ZodType);
+        expect(ListToolsResultSchema).toBeInstanceOf(z.ZodType);
+    });
+
+    it('schemas parse valid spec values', () => {
+        const parsed = CallToolRequestSchema.parse({
+            method: 'tools/call',
+            params: { name: 'echo', arguments: {} }
+        });
+        expect(parsed.method).toBe('tools/call');
+        expect(parsed.params.name).toBe('echo');
+    });
+});

packages/server/tsconfig.json

@@ -7,8 +7,10 @@
             "*": ["./*"],
             "@modelcontextprotocol/core": ["./node_modules/@modelcontextprotocol/core/src/index.ts"],
             "@modelcontextprotocol/core/public": ["./node_modules/@modelcontextprotocol/core/src/exports/public/index.ts"],
+            "@modelcontextprotocol/core/schemas": ["./node_modules/@modelcontextprotocol/core/src/types/schemas.ts"],
             "@modelcontextprotocol/test-helpers": ["./node_modules/@modelcontextprotocol/test-helpers/src/index.ts"],
-            "@modelcontextprotocol/server/_shims": ["./src/shimsNode.ts"]
+            "@modelcontextprotocol/server/_shims": ["./src/shimsNode.ts"],
+            "@modelcontextprotocol/server/zod-schemas": ["./src/zodSchemas.ts"]
         }
     }
 }

packages/server/tsdown.config.ts

@@ -4,7 +4,7 @@ export default defineConfig({
     failOnWarn: 'ci-only',
     // 1. Entry Points
     //    Directly matches package.json include/exclude globs
-    entry: ['src/index.ts', 'src/shimsNode.ts', 'src/shimsWorkerd.ts', 'src/validators/cfWorker.ts'],
+    entry: ['src/index.ts', 'src/zodSchemas.ts', 'src/shimsNode.ts', 'src/shimsWorkerd.ts', 'src/validators/cfWorker.ts'],
 
     // 2. Output Configuration
     format: ['esm'],
@@ -26,7 +26,8 @@ export default defineConfig({
             baseUrl: '.',
             paths: {
                 '@modelcontextprotocol/core': ['../core/src/index.ts'],
-                '@modelcontextprotocol/core/public': ['../core/src/exports/public/index.ts']
+                '@modelcontextprotocol/core/public': ['../core/src/exports/public/index.ts'],
+                '@modelcontextprotocol/core/schemas': ['../core/src/types/schemas.ts']
             }
         }
     },

packages/server/typedoc.json

@@ -2,7 +2,7 @@
     "$schema": "https://typedoc.org/schema.json",
     "entryPoints": ["src"],
     "entryPointStrategy": "expand",
-    "exclude": ["**/*.test.ts", "**/__*__/**"],
+    "exclude": ["**/*.test.ts", "**/__*__/**", "**/zodSchemas.ts"],
     "navigation": {
         "includeGroups": true,
         "includeCategories": true