fix: support Zod 3.25 method literals

src/client/index.ts

@@ -53,15 +53,7 @@ import {
 } from '../types.js';
 import { AjvJsonSchemaValidator } from '../validation/ajv-provider.js';
 import type { JsonSchemaType, JsonSchemaValidator, jsonSchemaValidator } from '../validation/types.js';
-import {
-    AnyObjectSchema,
-    SchemaOutput,
-    getObjectShape,
-    isZ4Schema,
-    safeParse,
-    type ZodV3Internal,
-    type ZodV4Internal
-} from '../server/zod-compat.js';
+import { AnyObjectSchema, SchemaOutput, getLiteralValue, getObjectShape, safeParse } from '../server/zod-compat.js';
 import type { RequestHandlerExtra } from '../shared/protocol.js';
 import { ExperimentalClientTasks } from '../experimental/tasks/client.js';
 import { assertToolsCallTaskCapability, assertClientRequestTaskCapability } from '../experimental/tasks/helpers.js';
@@ -339,18 +331,7 @@ export class Client<
             throw new Error('Schema is missing a method literal');
         }
 
-        // Extract literal value using type-safe property access
-        let methodValue: unknown;
-        if (isZ4Schema(methodSchema)) {
-            const v4Schema = methodSchema as unknown as ZodV4Internal;
-            const v4Def = v4Schema._zod?.def;
-            methodValue = v4Def?.value ?? v4Schema.value;
-        } else {
-            const v3Schema = methodSchema as unknown as ZodV3Internal;
-            const legacyDef = v3Schema._def;
-            methodValue = legacyDef?.value ?? v3Schema.value;
-        }
-
+        const methodValue = getLiteralValue(methodSchema);
         if (typeof methodValue !== 'string') {
             throw new Error('Schema method literal must be a string');
         }

src/server/index.ts

@@ -44,15 +44,7 @@ import {
 } from '../types.js';
 import { AjvJsonSchemaValidator } from '../validation/ajv-provider.js';
 import type { JsonSchemaType, jsonSchemaValidator } from '../validation/types.js';
-import {
-    AnyObjectSchema,
-    getObjectShape,
-    isZ4Schema,
-    safeParse,
-    SchemaOutput,
-    type ZodV3Internal,
-    type ZodV4Internal
-} from './zod-compat.js';
+import { AnyObjectSchema, getLiteralValue, getObjectShape, safeParse, SchemaOutput } from './zod-compat.js';
 import { RequestHandlerExtra } from '../shared/protocol.js';
 import { ExperimentalServerTasks } from '../experimental/tasks/server.js';
 import { assertToolsCallTaskCapability, assertClientRequestTaskCapability } from '../experimental/tasks/helpers.js';
@@ -228,18 +220,7 @@ export class Server<
             throw new Error('Schema is missing a method literal');
         }
 
-        // Extract literal value using type-safe property access
-        let methodValue: unknown;
-        if (isZ4Schema(methodSchema)) {
-            const v4Schema = methodSchema as unknown as ZodV4Internal;
-            const v4Def = v4Schema._zod?.def;
-            methodValue = v4Def?.value ?? v4Schema.value;
-        } else {
-            const v3Schema = methodSchema as unknown as ZodV3Internal;
-            const legacyDef = v3Schema._def;
-            methodValue = legacyDef?.value ?? v3Schema.value;
-        }
-
+        const methodValue = getLiteralValue(methodSchema);
         if (typeof methodValue !== 'string') {
             throw new Error('Schema method literal must be a string');
         }

test/issues/test_1380_zod325_literal.test.ts

@@ -0,0 +1,73 @@
+import { Client } from '../../src/client/index.js';
+import { Server } from '../../src/server/index.js';
+import type { AnyObjectSchema, AnySchema } from '../../src/server/zod-compat.js';
+import { getLiteralValue } from '../../src/server/zod-compat.js';
+
+function requestSchemaWithValuesLiteral(method: string): AnyObjectSchema {
+    return {
+        _zod: {
+            def: {
+                type: 'object',
+                shape: {
+                    method: {
+                        _zod: {
+                            def: {
+                                type: 'literal',
+                                values: [method]
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    } as unknown as AnyObjectSchema;
+}
+
+describe('Issue #1380: Zod 3.25.x v4 literal value shape', () => {
+    test('extracts literal values stored in _zod.def.values', () => {
+        const methodSchema = {
+            _zod: {
+                def: {
+                    type: 'literal',
+                    values: ['ping']
+                }
+            }
+        } as unknown as AnySchema;
+
+        expect(getLiteralValue(methodSchema)).toBe('ping');
+    });
+
+    test('registers server request handlers when the method literal uses _zod.def.values', () => {
+        const server = new Server(
+            { name: 'test server', version: '1.0' },
+            {
+                capabilities: {
+                    tools: {}
+                }
+            }
+        );
+
+        expect(() => {
+            server.setRequestHandler(requestSchemaWithValuesLiteral('tools/call'), () => ({
+                content: []
+            }));
+        }).not.toThrow();
+    });
+
+    test('registers client request handlers when the method literal uses _zod.def.values', () => {
+        const client = new Client(
+            { name: 'test client', version: '1.0' },
+            {
+                capabilities: {
+                    elicitation: {}
+                }
+            }
+        );
+
+        expect(() => {
+            client.setRequestHandler(requestSchemaWithValuesLiteral('elicitation/create'), () => ({
+                action: 'cancel'
+            }));
+        }).not.toThrow();
+    });
+});