feat: search and fetch mcp tools

coder · hugodutka · Aug 4, 2025 · Jul 28, 2025 · Jul 29, 2025 · Jul 31, 2025
commit a61194dfa938ceb3411d5418152273e45c4fd04d
diff --git a/coderd/coderd.go b/coderd/coderd.go
@@ -996,8 +996,12 @@ func New(options *Options) *API {
 			r.Use(
 				httpmw.RequireExperimentWithDevBypass(api.Experiments, codersdk.ExperimentOAuth2, codersdk.ExperimentMCPServerHTTP),
 			)
+
 			// MCP HTTP transport endpoint with mandatory authentication
-			r.Mount("/http", api.mcpHTTPHandler())
+			r.Mount("/http", api.standardMCPHTTPHandler())
+			// ChatGPT gets a dedicated endpoint with a limited set of tools.
+			// See the docstring of the chatgptMCPHTTPHandler for more details.
+			r.Mount("/chatgpt", api.chatgptMCPHTTPHandler())
 		})
 	})
 

diff --git a/coderd/mcp/mcp.go b/coderd/mcp/mcp.go
@@ -67,8 +67,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	s.streamableServer.ServeHTTP(w, r)
 }
 
-// RegisterTools registers all available MCP tools with the server
-func (s *Server) RegisterTools(client *codersdk.Client) error {
+// RegisterTools registers MCP tools with the server
+func (s *Server) RegisterTools(client *codersdk.Client, tools []toolsdk.GenericTool) error {
 	if client == nil {
 		return xerrors.New("client cannot be nil: MCP HTTP server requires authenticated client")
 	}
@@ -79,13 +79,7 @@ func (s *Server) RegisterTools(client *codersdk.Client) error {
 		return xerrors.Errorf("failed to initialize tool dependencies: %w", err)
 	}
 
-	// Register all available tools, but exclude tools that require dependencies not available in the
-	// remote MCP context
-	for _, tool := range toolsdk.All {
-		if tool.Name == toolsdk.ToolNameReportTask {
-			continue
-		}
-
+	for _, tool := range tools {
 		s.mcpServer.AddTools(mcpFromSDK(tool, toolDeps))
 	}
 	return nil

diff --git a/coderd/mcp/mcp_test.go b/coderd/mcp/mcp_test.go
@@ -110,13 +110,13 @@ func TestMCPHTTP_ToolRegistration(t *testing.T) {
 	require.NoError(t, err)
 
 	// Test registering tools with nil client should return error
-	err = server.RegisterTools(nil)
+	err = server.RegisterTools(nil, toolsdk.All)
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "client cannot be nil", "Should reject nil client with appropriate error message")
 
 	// Test registering tools with valid client should succeed
 	client := &codersdk.Client{}
-	err = server.RegisterTools(client)
+	err = server.RegisterTools(client, toolsdk.All)
 	require.NoError(t, err)
 
 	// Verify that all expected tools are available in the toolsdk

diff --git a/coderd/mcp_http.go b/coderd/mcp_http.go
@@ -9,10 +9,11 @@ import (
 	"github.com/coder/coder/v2/coderd/httpmw"
 	"github.com/coder/coder/v2/coderd/mcp"
 	"github.com/coder/coder/v2/codersdk"
+	"github.com/coder/coder/v2/codersdk/toolsdk"
 )
 
 // mcpHTTPHandler creates the MCP HTTP transport handler
-func (api *API) mcpHTTPHandler() http.Handler {
+func (api *API) mcpHTTPHandler(tools []toolsdk.GenericTool) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		// Create MCP server instance for each request
 		mcpServer, err := mcp.NewServer(api.Logger.Named("mcp"))
@@ -29,11 +30,45 @@ func (api *API) mcpHTTPHandler() http.Handler {
 		authenticatedClient.SetSessionToken(httpmw.APITokenFromRequest(r))
 
 		// Register tools with authenticated client
-		if err := mcpServer.RegisterTools(authenticatedClient); err != nil {
+		if err := mcpServer.RegisterTools(authenticatedClient, tools); err != nil {
 			api.Logger.Warn(r.Context(), "failed to register MCP tools", slog.Error(err))
 		}
 
 		// Handle the MCP request
 		mcpServer.ServeHTTP(w, r)
 	})
 }
+
+// standardMCPHTTPHandler sets up the MCP HTTP transport handler for the standard tools.
+// Standard tools are all tools except for the report task, ChatGPT search, and ChatGPT fetch tools.
+func (api *API) standardMCPHTTPHandler() http.Handler {
+	mcpTools := []toolsdk.GenericTool{}
+	// Register all available tools, but exclude:
+	// - ReportTask - which requires dependencies not available in the remote MCP context
+	// - ChatGPT search and fetch tools, which are redundant with the standard tools.
+	for _, tool := range toolsdk.All {
+		if tool.Name == toolsdk.ToolNameReportTask ||
+			tool.Name == toolsdk.ToolNameChatGPTSearch || tool.Name == toolsdk.ToolNameChatGPTFetch {
+			continue
+		}
+		mcpTools = append(mcpTools, tool)
+	}
+	return api.mcpHTTPHandler(mcpTools)
+}
+
+// chatgptMCPHTTPHandler sets up the MCP HTTP transport handler for the ChatGPT tools.
+// ChatGPT tools are the search and fetch tools as defined in https://platform.openai.com/docs/mcp.
+// We do not expose any extra ones because ChatGPT has an undocumented "Safety Scan" feature.
+// In my experiments, if I included extra tools in the MCP server, ChatGPT would refuse
+// to add Coder as a connector.
+func (api *API) chatgptMCPHTTPHandler() http.Handler {
+	mcpTools := []toolsdk.GenericTool{}
+	// Register only the ChatGPT search and fetch tools.
+	for _, tool := range toolsdk.All {
+		if !(tool.Name == toolsdk.ToolNameChatGPTSearch || tool.Name == toolsdk.ToolNameChatGPTFetch) {
+			continue
+		}
+		mcpTools = append(mcpTools, tool)
+	}
+	return api.mcpHTTPHandler(mcpTools)
+}