fix(merge): drop codemod task-method entries (SEP-2663); fix consumer CHANGELOG core-internal refs

Author: felixweinberger

.changeset/codemod-task-handler-methods.md

@@ -2,4 +2,4 @@
 '@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.
+Emit a dedicated action-required diagnostic for v1 task-handler registrations (`setRequestHandler(GetTaskRequestSchema, …)`, `setNotificationHandler(TaskStatusNotificationSchema, …)`, and the other `tasks/*` schemas). The experimental tasks feature was removed in v2 (SEP-2663) and the `tasks/*` method strings are excluded from the typed `RequestMethod` / `NotificationMethod` surface, so these registrations are **not** rewritten to method-string form — the codemod marks each site with an `@mcp-codemod-error` comment pointing at the migration guide's tasks-removed section instead.

docs/migration/upgrade-to-v2.md

@@ -76,9 +76,11 @@ In addition the codemod:
   spec methods.
 - Routes the spec Zod `*Schema` constants imported from `sdk/types.js` to
   `@modelcontextprotocol/core` (mixed imports are split; `.parse()` / `.safeParse()`
-  calls are left untouched). The task-handler schema constants
-  (`GetTaskRequestSchema` etc.) used as `setRequestHandler` args are mapped to their
-  method strings (`'tasks/get'` etc.) like every other handler schema.
+  calls are left untouched). Task-handler schema constants
+  (`GetTaskRequestSchema` etc.) used as `setRequestHandler` args are **not** rewritten
+  — the experimental tasks feature was removed (SEP-2663), so each such registration
+  is marked with an action-required diagnostic instead (see
+  [Experimental tasks interception removed](#experimental-tasks-interception-removed)).
 - Renames `ErrorCode` → `ProtocolErrorCode` and routes the local-only members
   (`RequestTimeout`, `ConnectionClosed`) to `SdkErrorCode`.
 - Renames every `StreamableHTTPError` reference to `SdkHttpError` and adds the import

packages/client/CHANGELOG.md

@@ -73,7 +73,7 @@
 
 - [#2275](https://github.com/modelcontextprotocol/typescript-sdk/pull/2275) [`1b53a41`](https://github.com/modelcontextprotocol/typescript-sdk/commit/1b53a415ea2c33aa11ac413fc9c2d68ccffde784) Thanks [@KKonstantinov](https://github.com/KKonstantinov)! - Add a configurable
   `maxBufferSize` (default 10 MB) to the stdio transports. When a single message would push the read buffer past the limit, the transport now emits an `onerror` and closes instead of growing the buffer unbounded. Configure via `new StdioClientTransport({ ..., maxBufferSize })` or
-  `new StdioServerTransport(stdin, stdout, { maxBufferSize })`. The default is exported from `@modelcontextprotocol/core-internal` as `STDIO_DEFAULT_MAX_BUFFER_SIZE`.
+  `new StdioServerTransport(stdin, stdout, { maxBufferSize })`. The default is exported from `@modelcontextprotocol/client` / `@modelcontextprotocol/server` as `STDIO_DEFAULT_MAX_BUFFER_SIZE`.
 
 - [#2088](https://github.com/modelcontextprotocol/typescript-sdk/pull/2088) [`16d13ab`](https://github.com/modelcontextprotocol/typescript-sdk/commit/16d13abf78b5dba5de73dfa284325b13d4219bb2) Thanks [@mattzcarey](https://github.com/mattzcarey)! - Bundle automatic JSON Schema
   validator defaults in `@modelcontextprotocol/client` and `@modelcontextprotocol/server` runtime shims.
@@ -160,7 +160,8 @@
     For raw JSON Schema (e.g. TypeBox output), use the new `fromJsonSchema` adapter:
 
     ```typescript
-    import { fromJsonSchema, AjvJsonSchemaValidator } from '@modelcontextprotocol/core-internal';
+    import { fromJsonSchema } from '@modelcontextprotocol/server';
+    import { AjvJsonSchemaValidator } from '@modelcontextprotocol/server/validators/ajv';
 
     server.registerTool(
         'greet',

packages/codemod/src/migrations/v1-to-v2/mappings/schemaToMethodMap.ts

@@ -14,11 +14,7 @@ export const SCHEMA_TO_METHOD: Record<string, string> = {
     SetLevelRequestSchema: 'logging/setLevel',
     PingRequestSchema: 'ping',
     CompleteRequestSchema: 'completion/complete',
-    ListRootsRequestSchema: 'roots/list',
-    GetTaskRequestSchema: 'tasks/get',
-    GetTaskPayloadRequestSchema: 'tasks/result',
-    ListTasksRequestSchema: 'tasks/list',
-    CancelTaskRequestSchema: 'tasks/cancel'
+    ListRootsRequestSchema: 'roots/list'
 };
 
 export const NOTIFICATION_SCHEMA_TO_METHOD: Record<string, string> = {
@@ -31,6 +27,21 @@ export const NOTIFICATION_SCHEMA_TO_METHOD: Record<string, string> = {
     CancelledNotificationSchema: 'notifications/cancelled',
     InitializedNotificationSchema: 'notifications/initialized',
     RootsListChangedNotificationSchema: 'notifications/roots/list_changed',
-    ElicitationCompleteNotificationSchema: 'notifications/elicitation/complete',
-    TaskStatusNotificationSchema: 'notifications/tasks/status'
+    ElicitationCompleteNotificationSchema: 'notifications/elicitation/complete'
 };
+
+/**
+ * v1 task-handler schema names. The experimental tasks feature was removed in v2
+ * (SEP-2663) and the task method strings are excluded from the typed
+ * `RequestMethod` / `NotificationMethod` surface, so these are NOT in the rewrite
+ * maps above — the handler-registration transform emits a dedicated
+ * action-required diagnostic instead.
+ */
+export const REMOVED_TASK_SCHEMAS: ReadonlySet<string> = new Set([
+    'GetTaskRequestSchema',
+    'GetTaskPayloadRequestSchema',
+    'ListTasksRequestSchema',
+    'CancelTaskRequestSchema',
+    'CreateTaskRequestSchema',
+    'TaskStatusNotificationSchema'
+]);

packages/codemod/src/migrations/v1-to-v2/transforms/handlerRegistration.ts

@@ -4,7 +4,7 @@ import { Node, SyntaxKind } from 'ts-morph';
 import type { Diagnostic, Transform, TransformContext, TransformResult } from '../../../types';
 import { actionRequired } from '../../../utils/diagnostics';
 import { hasMcpImports, isImportedFromMcp, removeUnusedImport, resolveOriginalImportName } from '../../../utils/importUtils';
-import { NOTIFICATION_SCHEMA_TO_METHOD, SCHEMA_TO_METHOD } from '../mappings/schemaToMethodMap';
+import { NOTIFICATION_SCHEMA_TO_METHOD, REMOVED_TASK_SCHEMAS, SCHEMA_TO_METHOD } from '../mappings/schemaToMethodMap';
 
 const ALL_SCHEMA_TO_METHOD: Record<string, string> = {
     ...SCHEMA_TO_METHOD,
@@ -41,6 +41,21 @@ export const handlerRegistrationTransform: Transform = {
 
             const schemaName = firstArg.getText();
             const originalName = resolveOriginalImportName(sourceFile, schemaName) ?? schemaName;
+
+            if (REMOVED_TASK_SCHEMAS.has(originalName) && isImportedFromMcp(sourceFile, schemaName)) {
+                diagnostics.push(
+                    actionRequired(
+                        sourceFile.getFilePath(),
+                        call,
+                        `Task handler registration: ${methodName}(${schemaName}, ...). ` +
+                            `The experimental tasks feature was removed in v2 (SEP-2663); the tasks/* method strings ` +
+                            `are not part of the typed RequestMethod surface. Remove this registration. ` +
+                            `See docs/migration/upgrade-to-v2.md#experimental-tasks-interception-removed.`
+                    )
+                );
+                continue;
+            }
+
             const methodString = ALL_SCHEMA_TO_METHOD[originalName];
             if (!methodString) {
                 diagnostics.push(

packages/codemod/test/v1-to-v2/transforms/handlerRegistration.test.ts

@@ -219,26 +219,39 @@ describe('handler-registration transform', () => {
         expect(result).not.toContain('ElicitationCompleteNotificationSchema');
     });
 
-    it('replaces TaskStatusNotificationSchema with the tasks/status method string', () => {
+    it('emits a tasks-removed diagnostic for GetTaskRequestSchema (does NOT rewrite to tasks/get)', () => {
         const input = [
-            `import { TaskStatusNotificationSchema } from '@modelcontextprotocol/sdk/types.js';`,
-            `client.setNotificationHandler(TaskStatusNotificationSchema, async () => {});`,
+            `import { GetTaskRequestSchema } from '@modelcontextprotocol/sdk/types.js';`,
+            `server.setRequestHandler(GetTaskRequestSchema, async () => ({}));`,
             ''
         ].join('\n');
-        const result = applyTransform(input);
-        expect(result).toContain("setNotificationHandler('notifications/tasks/status'");
-        expect(result).not.toContain('TaskStatusNotificationSchema');
+        const project = new Project({ useInMemoryFileSystem: true });
+        const sourceFile = project.createSourceFile('test.ts', input);
+        const result = handlerRegistrationTransform.apply(sourceFile, ctx);
+        const text = sourceFile.getFullText();
+        expect(text).not.toContain("'tasks/get'");
+        expect(text).toContain('setRequestHandler(GetTaskRequestSchema');
+        expect(result.changesCount).toBe(0);
+        expect(result.diagnostics.length).toBe(1);
+        expect(result.diagnostics[0]!.message).toContain('Task handler registration');
+        expect(result.diagnostics[0]!.message).toContain('SEP-2663');
     });
 
-    it('replaces task request schemas (GetTaskRequestSchema → tasks/get)', () => {
+    it('emits a tasks-removed diagnostic for TaskStatusNotificationSchema (does NOT rewrite)', () => {
         const input = [
-            `import { GetTaskRequestSchema } from '@modelcontextprotocol/sdk/types.js';`,
-            `server.setRequestHandler(GetTaskRequestSchema, async () => ({}));`,
+            `import { TaskStatusNotificationSchema } from '@modelcontextprotocol/sdk/types.js';`,
+            `client.setNotificationHandler(TaskStatusNotificationSchema, async () => {});`,
             ''
         ].join('\n');
-        const result = applyTransform(input);
-        expect(result).toContain("setRequestHandler('tasks/get'");
-        expect(result).not.toContain('GetTaskRequestSchema');
+        const project = new Project({ useInMemoryFileSystem: true });
+        const sourceFile = project.createSourceFile('test.ts', input);
+        const result = handlerRegistrationTransform.apply(sourceFile, ctx);
+        const text = sourceFile.getFullText();
+        expect(text).not.toContain("'notifications/tasks/status'");
+        expect(text).toContain('setNotificationHandler(TaskStatusNotificationSchema');
+        expect(result.changesCount).toBe(0);
+        expect(result.diagnostics.length).toBe(1);
+        expect(result.diagnostics[0]!.message).toContain('Task handler registration');
     });
 
     it('does not emit diagnostic when first arg is a string literal (v2 style)', () => {

packages/server/CHANGELOG.md

@@ -81,7 +81,7 @@
 
 - [#2275](https://github.com/modelcontextprotocol/typescript-sdk/pull/2275) [`1b53a41`](https://github.com/modelcontextprotocol/typescript-sdk/commit/1b53a415ea2c33aa11ac413fc9c2d68ccffde784) Thanks [@KKonstantinov](https://github.com/KKonstantinov)! - Add a configurable
   `maxBufferSize` (default 10 MB) to the stdio transports. When a single message would push the read buffer past the limit, the transport now emits an `onerror` and closes instead of growing the buffer unbounded. Configure via `new StdioClientTransport({ ..., maxBufferSize })` or
-  `new StdioServerTransport(stdin, stdout, { maxBufferSize })`. The default is exported from `@modelcontextprotocol/core-internal` as `STDIO_DEFAULT_MAX_BUFFER_SIZE`.
+  `new StdioServerTransport(stdin, stdout, { maxBufferSize })`. The default is exported from `@modelcontextprotocol/client` / `@modelcontextprotocol/server` as `STDIO_DEFAULT_MAX_BUFFER_SIZE`.
 
 - [#2088](https://github.com/modelcontextprotocol/typescript-sdk/pull/2088) [`16d13ab`](https://github.com/modelcontextprotocol/typescript-sdk/commit/16d13abf78b5dba5de73dfa284325b13d4219bb2) Thanks [@mattzcarey](https://github.com/mattzcarey)! - Bundle automatic JSON Schema
   validator defaults in `@modelcontextprotocol/client` and `@modelcontextprotocol/server` runtime shims.
@@ -158,7 +158,8 @@
     For raw JSON Schema (e.g. TypeBox output), use the new `fromJsonSchema` adapter:
 
     ```typescript
-    import { fromJsonSchema, AjvJsonSchemaValidator } from '@modelcontextprotocol/core-internal';
+    import { fromJsonSchema } from '@modelcontextprotocol/server';
+    import { AjvJsonSchemaValidator } from '@modelcontextprotocol/server/validators/ajv';
 
     server.registerTool(
         'greet',