temp: make gopher-auth just provides registerOAuthRoutes and expressMiddleware

Author: RahulHere

include/mcp/auth/auth_c_api.h

@@ -197,6 +197,18 @@ mcp_auth_error_t mcp_auth_validate_token(
     mcp_auth_validation_options_t options,
     mcp_auth_validation_result_t* result);
 
+/**
+ * @brief Validate a JWT token (returns result by value for FFI compatibility)
+ * @param client Client handle
+ * @param token JWT token string
+ * @param options Validation options (can be NULL for defaults)
+ * @return Validation result struct
+ */
+mcp_auth_validation_result_t mcp_auth_validate_token_ret(
+    mcp_auth_client_t client,
+    const char* token,
+    mcp_auth_validation_options_t options);
+
 /**
  * @brief Extract token payload without validation
  * @param token JWT token string

sdk/typescript/README-AUTH.md

@@ -0,0 +1,265 @@
+# @mcp/filter-sdk Authentication
+
+The @mcp/filter-sdk provides two usage patterns for authentication, making it compatible with different coding styles and requirements.
+
+## Two Usage Patterns
+
+### Pattern 1: Express-Style APIs (NEW)
+
+Similar to `gopher-auth-sdk-nodejs`, this pattern provides explicit control through two main APIs:
+
+1. **`registerOAuthRoutes(app, options)`** - Registers OAuth discovery and proxy endpoints
+2. **`expressMiddleware(options)`** - Creates authentication middleware for Express
+
+```typescript
+import express from 'express';
+import { McpExpressAuth } from '@mcp/filter-sdk/auth';
+
+const app = express();
+const auth = new McpExpressAuth();
+
+// API 1: Register OAuth routes
+auth.registerOAuthRoutes(app, {
+  serverUrl: 'http://localhost:3001',
+  allowedScopes: ['mcp:weather', 'openid']
+});
+
+// API 2: Use authentication middleware
+app.all('/mcp',
+  auth.expressMiddleware({
+    publicMethods: ['initialize'],
+    toolScopes: {
+      'get-forecast': ['mcp:weather']
+    }
+  }),
+  mcpHandler
+);
+```
+
+### Pattern 2: Simple AuthenticatedMcpServer (EXISTING)
+
+The original pattern for quick setup with minimal configuration:
+
+```typescript
+import { AuthenticatedMcpServer } from '@mcp/filter-sdk/auth';
+
+const server = new AuthenticatedMcpServer();
+server.register(tools);
+await server.start();
+```
+
+## Configuration
+
+Both patterns support configuration through:
+- Constructor parameters
+- Environment variables
+- Mixed approach
+
+### Environment Variables
+
+```bash
+# OAuth Server Configuration
+GOPHER_AUTH_SERVER_URL=http://localhost:8080/realms/gopher-auth
+GOPHER_CLIENT_ID=mcp-server
+GOPHER_CLIENT_SECRET=secret
+
+# Optional
+JWKS_URI=http://localhost:8080/realms/gopher-auth/protocol/openid-connect/certs
+TOKEN_ISSUER=http://localhost:8080/realms/gopher-auth
+TOKEN_AUDIENCE=mcp-server
+JWKS_CACHE_DURATION=3600
+REQUEST_TIMEOUT=10
+```
+
+## Express Pattern Details
+
+### registerOAuthRoutes
+
+Creates these endpoints:
+- `/.well-known/oauth-protected-resource` - Protected resource metadata (RFC 9728)
+- `/.well-known/oauth-authorization-server` - OAuth metadata proxy (RFC 8414)
+- `/realms/:realm/clients-registrations/openid-connect` - Client registration proxy
+
+Options:
+```typescript
+interface OAuthProxyOptions {
+  serverUrl: string;           // Your MCP server URL
+  allowedScopes?: string[];    // Scopes to allow (default: ['openid'])
+}
+```
+
+### expressMiddleware
+
+Creates Express middleware for token validation:
+
+Options:
+```typescript
+interface ExpressMiddlewareOptions {
+  audience?: string | string[];              // Expected audience(s)
+  publicPaths?: string[];                   // Paths without auth
+  publicMethods?: string[];                 // MCP methods without auth
+  toolScopes?: Record<string, string[]>;    // Tool-specific scopes
+}
+```
+
+## Complete Examples
+
+### Express Pattern with Full Control
+
+```typescript
+import express from 'express';
+import { McpExpressAuth } from '@mcp/filter-sdk/auth';
+import { Server } from '@modelcontextprotocol/sdk/server/index.js';
+
+const app = express();
+app.use(express.json());
+
+// Initialize auth
+const auth = new McpExpressAuth({
+  issuer: 'http://localhost:8080/realms/gopher-auth',
+  jwksUri: 'http://localhost:8080/realms/gopher-auth/protocol/openid-connect/certs',
+  tokenAudience: 'mcp-server'
+});
+
+// Register OAuth routes
+auth.registerOAuthRoutes(app, {
+  serverUrl: 'http://localhost:3001',
+  allowedScopes: ['mcp:weather', 'openid']
+});
+
+// Create MCP server
+const mcpServer = new Server(
+  { name: 'weather-server', version: '1.0.0' },
+  { capabilities: { tools: {} } }
+);
+
+// Protected MCP endpoint
+app.all('/mcp',
+  auth.expressMiddleware({
+    publicMethods: ['initialize'],
+    toolScopes: {
+      'get-forecast': ['mcp:weather'],
+      'get-alerts': ['mcp:weather', 'mcp:admin']
+    }
+  }),
+  async (req, res) => {
+    const user = (req as any).auth;
+    console.log('User:', user?.subject);
+    // Handle MCP request
+    await handleMcpRequest(req, res);
+  }
+);
+
+// Additional authenticated API
+app.get('/api/status',
+  auth.expressMiddleware(),
+  (req, res) => {
+    const user = (req as any).auth;
+    res.json({ user: user?.subject, status: 'ok' });
+  }
+);
+
+app.listen(3001);
+```
+
+### Simple Pattern (Backward Compatible)
+
+```typescript
+import { AuthenticatedMcpServer, Tool } from '@mcp/filter-sdk/auth';
+import dotenv from 'dotenv';
+
+dotenv.config();
+
+const tools: Tool[] = [
+  {
+    name: 'get-weather',
+    description: 'Get weather',
+    inputSchema: { /* ... */ },
+    handler: async (req) => { /* ... */ }
+  }
+];
+
+// Simple setup - config from environment
+const server = new AuthenticatedMcpServer();
+server.register(tools);
+await server.start();
+```
+
+### Hybrid Usage
+
+You can use both patterns together:
+
+```typescript
+import { AuthenticatedMcpServer, McpExpressAuth } from '@mcp/filter-sdk/auth';
+
+// Use AuthenticatedMcpServer for MCP
+const mcpServer = new AuthenticatedMcpServer({
+  transport: 'http',
+  serverPort: 3001
+});
+mcpServer.register(tools);
+
+// Also use Express auth for custom endpoints
+const auth = new McpExpressAuth();
+const app = express();
+
+auth.registerOAuthRoutes(app, {
+  serverUrl: 'http://localhost:3001',
+  allowedScopes: ['mcp:weather']
+});
+
+app.get('/custom-api',
+  auth.expressMiddleware(),
+  (req, res) => {
+    // Custom authenticated endpoint
+  }
+);
+```
+
+## Migration Guide
+
+### From No Auth to OAuth
+
+Before:
+```typescript
+const server = new Server(...);
+// No authentication
+```
+
+After (Simple):
+```typescript
+const server = new AuthenticatedMcpServer();
+// OAuth enabled
+```
+
+After (Express):
+```typescript
+const auth = new McpExpressAuth();
+auth.registerOAuthRoutes(app, options);
+app.all('/mcp', auth.expressMiddleware(options), handler);
+```
+
+### From gopher-auth-sdk-nodejs
+
+The Express pattern APIs are designed to be similar:
+
+gopher-auth-sdk-nodejs:
+```typescript
+const auth = new GopherAuth(config);
+auth.registerOAuthRoutes(app, options);
+app.all('/mcp', auth.expressMiddleware(options), handler);
+```
+
+@mcp/filter-sdk:
+```typescript
+const auth = new McpExpressAuth(config);
+auth.registerOAuthRoutes(app, options);
+app.all('/mcp', auth.expressMiddleware(options), handler);
+```
+
+## Benefits
+
+- **Pattern 1 (Express)**: Full control, explicit configuration, custom endpoints
+- **Pattern 2 (Simple)**: Quick setup, convention over configuration, minimal code
+
+Choose the pattern that best fits your needs. Both are fully supported and can be used together.