feat(sep-834): full McpServer support for any outputSchema type

Add support for array and primitive outputSchema in McpServer high-level API:

- Add toJsonSchemaCompatAny() for converting any Zod schema to JSON Schema
- Add normalizeAnySchema() for handling any schema type (not just objects)
- Update McpServer to use these for outputSchema conversion and validation
- Add shx for cross-platform build scripts

This enables the key SEP-834 use cases:
- outputSchema with type: "array" at root (e.g., z.array(UserSchema))
- outputSchema with primitive types (e.g., z.number())
- structuredContent containing raw arrays or primitives

Published as @olaservo/mcp-sdk@1.25.2-sep834.1

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: olaservo

package-lock.json

@@ -1,7 +1,7 @@
 {
-    "name": "@modelcontextprotocol/sdk",
-    "version": "1.25.2",
-    "description": "Model Context Protocol implementation for TypeScript",
+    "name": "@olaservo/mcp-sdk",
+    "version": "1.25.2-sep834.1",
+    "description": "Model Context Protocol implementation for TypeScript (SEP-834 fork with loosened JSON Schema restrictions)",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
     "homepage": "https://modelcontextprotocol.io",
@@ -70,9 +70,9 @@
         "fetch:spec-types": "tsx scripts/fetch-spec-types.ts",
         "typecheck": "tsgo --noEmit",
         "build": "npm run build:esm && npm run build:cjs",
-        "build:esm": "mkdir -p dist/esm && echo '{\"type\": \"module\"}' > dist/esm/package.json && tsc -p tsconfig.prod.json",
+        "build:esm": "shx mkdir -p dist/esm && shx echo '{\"type\": \"module\"}' > dist/esm/package.json && tsc -p tsconfig.prod.json",
         "build:esm:w": "npm run build:esm -- -w",
-        "build:cjs": "mkdir -p dist/cjs && echo '{\"type\": \"commonjs\"}' > dist/cjs/package.json && tsc -p tsconfig.cjs.json",
+        "build:cjs": "shx mkdir -p dist/cjs && shx echo '{\"type\": \"commonjs\"}' > dist/cjs/package.json && tsc -p tsconfig.cjs.json",
         "build:cjs:w": "npm run build:cjs -- -w",
         "examples:simple-server:w": "tsx --watch src/examples/server/simpleStreamableHttp.ts --oauth",
         "prepack": "npm run build:esm && npm run build:cjs",
@@ -132,6 +132,7 @@
         "eslint-config-prettier": "^10.1.8",
         "eslint-plugin-n": "^17.23.1",
         "prettier": "3.6.2",
+        "shx": "^0.3.4",
         "supertest": "^7.0.0",
         "tsx": "^4.16.5",
         "typescript": "^5.5.4",

package.json

@@ -6,6 +6,7 @@ import {
     SchemaOutput,
     ShapeOutput,
     normalizeObjectSchema,
+    normalizeAnySchema,
     safeParseAsync,
     getObjectShape,
     objectFromShape,
@@ -14,7 +15,7 @@ import {
     isSchemaOptional,
     getLiteralValue
 } from './zod-compat.js';
-import { toJsonSchemaCompat } from './zod-json-schema-compat.js';
+import { toJsonSchemaCompat, toJsonSchemaCompatAny } from './zod-json-schema-compat.js';
 import {
     Implementation,
     Tool,
@@ -160,9 +161,10 @@ export class McpServer {
                         };
 
                         if (tool.outputSchema) {
-                            const obj = normalizeObjectSchema(tool.outputSchema);
-                            if (obj) {
-                                toolDefinition.outputSchema = toJsonSchemaCompat(obj, {
+                            // SEP-834: Support any schema type for outputSchema (array, primitive, object)
+                            const schema = normalizeAnySchema(tool.outputSchema);
+                            if (schema) {
+                                toolDefinition.outputSchema = toJsonSchemaCompatAny(schema, {
                                     strictUnions: true,
                                     pipeStrategy: 'output'
                                 }) as Tool['outputSchema'];
@@ -305,9 +307,9 @@ export class McpServer {
             );
         }
 
-        // if the tool has an output schema, validate structured content
-        const outputObj = normalizeObjectSchema(tool.outputSchema) as AnyObjectSchema;
-        const parseResult = await safeParseAsync(outputObj, result.structuredContent);
+        // SEP-834: if the tool has an output schema, validate structured content (supports any schema type)
+        const outputSchema = normalizeAnySchema(tool.outputSchema);
+        const parseResult = await safeParseAsync(outputSchema as AnySchema, result.structuredContent);
         if (!parseResult.success) {
             const error = 'error' in parseResult ? parseResult.error : 'Unknown error';
             const errorMessage = getParseErrorMessage(error);