feat: auto-infer streamable-http type for MCP servers with URL configuration

- Modified validateServerConfig to auto-infer streamable-http when URL is present without explicit type
- Updated ServerConfigSchema to prioritize streamable-http over SSE for URL configs
- SSE now requires explicit type specification
- Added comprehensive test coverage for URL auto-inference
- Maintains full backward compatibility with existing configs

Fixes #9118

src/services/mcp/McpHub.ts

@@ -77,7 +77,7 @@ const streamableHttpFieldsErrorMessage =
 const mixedFieldsErrorMessage =
 	"Cannot mix 'stdio' and ('sse' or 'streamable-http') fields. For 'stdio' use 'command', 'args', and 'env'. For 'sse'/'streamable-http' use 'url' and 'headers'"
 const missingFieldsErrorMessage =
-	"Server configuration must include either 'command' (for stdio) or 'url' (for sse/streamable-http) and a corresponding 'type' if 'url' is used."
+	"Server configuration must include either 'command' (for stdio) or 'url' (for sse/streamable-http). When 'url' is present without 'type', 'streamable-http' will be inferred."
 
 // Helper function to create a refined schema with better error messages
 const createServerTypeSchema = () => {
@@ -98,22 +98,7 @@ const createServerTypeSchema = () => {
 				type: "stdio" as const,
 			}))
 			.refine((data) => data.type === undefined || data.type === "stdio", { message: typeErrorMessage }),
-		// SSE config (has url field)
-		BaseConfigSchema.extend({
-			type: z.enum(["sse"]).optional(),
-			url: z.string().url("URL must be a valid URL format"),
-			headers: z.record(z.string()).optional(),
-			// Ensure no stdio fields are present
-			command: z.undefined().optional(),
-			args: z.undefined().optional(),
-			env: z.undefined().optional(),
-		})
-			.transform((data) => ({
-				...data,
-				type: "sse" as const,
-			}))
-			.refine((data) => data.type === undefined || data.type === "sse", { message: typeErrorMessage }),
-		// StreamableHTTP config (has url field)
+		// StreamableHTTP config (has url field, default for URL-based configs)
 		BaseConfigSchema.extend({
 			type: z.enum(["streamable-http"]).optional(),
 			url: z.string().url("URL must be a valid URL format"),
@@ -130,6 +115,16 @@ const createServerTypeSchema = () => {
 			.refine((data) => data.type === undefined || data.type === "streamable-http", {
 				message: typeErrorMessage,
 			}),
+		// SSE config (requires explicit type="sse")
+		BaseConfigSchema.extend({
+			type: z.enum(["sse"]),
+			url: z.string().url("URL must be a valid URL format"),
+			headers: z.record(z.string()).optional(),
+			// Ensure no stdio fields are present
+			command: z.undefined().optional(),
+			args: z.undefined().optional(),
+			env: z.undefined().optional(),
+		}).refine((data) => data.type === "sse", { message: typeErrorMessage }),
 	])
 }
 
@@ -209,9 +204,9 @@ export class McpHub {
 			config.type = "stdio"
 		}
 
-		// For url-based configs, type must be provided by the user
+		// For url-based configs, auto-infer type as 'streamable-http' if not provided
 		if (hasUrlFields && !config.type) {
-			throw new Error("Configuration with 'url' must explicitly specify 'type' as 'sse' or 'streamable-http'.")
+			config.type = "streamable-http"
 		}
 
 		// Validate type if provided
@@ -1378,8 +1373,8 @@ export class McpHub {
 						await this.deleteConnection(serverName, serverSource)
 						// Re-add as a disabled connection
 						// Re-read config from file to get updated disabled state
-					const updatedConfig = await this.readServerConfigFromFile(serverName, serverSource)
-					await this.connectToServer(serverName, updatedConfig, serverSource)
+						const updatedConfig = await this.readServerConfigFromFile(serverName, serverSource)
+						await this.connectToServer(serverName, updatedConfig, serverSource)
 					} else if (!disabled && connection.server.status === "disconnected") {
 						// If enabling a disabled server, connect it
 						// Re-read config from file to get updated disabled state

src/services/mcp/__tests__/McpHub.spec.ts

@@ -2147,4 +2147,94 @@ describe("McpHub", () => {
 			)
 		})
 	})
+
+	describe("URL type auto-inference", () => {
+		it("should auto-infer 'streamable-http' type when URL is present without explicit type", () => {
+			const config = {
+				url: "https://api.example.com/mcp",
+				headers: {
+					Authorization: "Bearer token",
+				},
+			}
+
+			const result = ServerConfigSchema.parse(config)
+			expect(result.type).toBe("streamable-http")
+		})
+
+		it("should preserve explicit 'sse' type when specified with URL", () => {
+			const config = {
+				type: "sse",
+				url: "https://api.example.com/mcp",
+				headers: {
+					Authorization: "Bearer token",
+				},
+			}
+
+			const result = ServerConfigSchema.parse(config)
+			expect(result.type).toBe("sse")
+		})
+
+		it("should preserve explicit 'streamable-http' type when specified", () => {
+			const config = {
+				type: "streamable-http",
+				url: "https://api.example.com/mcp",
+			}
+
+			const result = ServerConfigSchema.parse(config)
+			expect(result.type).toBe("streamable-http")
+		})
+
+		it("should maintain backward compatibility for stdio type", () => {
+			const config = {
+				command: "node",
+				args: ["server.js"],
+			}
+
+			const result = ServerConfigSchema.parse(config)
+			expect(result.type).toBe("stdio")
+		})
+
+		it("should work with minimal URL config", () => {
+			const config = {
+				url: "https://docs.langchain.com/mcp",
+			}
+
+			const result = ServerConfigSchema.parse(config)
+			expect(result.type).toBe("streamable-http")
+		})
+
+		it("should auto-infer for GitHub Copilot-like config", () => {
+			const config = {
+				url: "https://api.githubcopilot.com/mcp",
+				headers: {
+					Authorization: "Bearer GITHUB_PAT",
+				},
+				alwaysAllow: ["SearchDocsByLangChain"],
+			}
+
+			const result = ServerConfigSchema.parse(config)
+			expect(result.type).toBe("streamable-http")
+		})
+
+		it("should reject invalid URL", () => {
+			const config = {
+				url: "not-a-url",
+			}
+
+			expect(() => ServerConfigSchema.parse(config)).toThrow("URL must be a valid URL format")
+		})
+
+		it("should reject mixed stdio and URL fields", () => {
+			const config = {
+				command: "node",
+				url: "https://api.example.com/mcp",
+			}
+
+			// This should be caught by the validateServerConfig function
+			const mcpHub = new McpHub(mockProvider as ClineProvider)
+			expect(() => mcpHub["validateServerConfig"](config)).toThrow(
+				"Cannot mix 'stdio' and ('sse' or 'streamable-http') fields",
+			)
+		})
+	})
 })