feat: add --json-response CLI flag

Merge pull request #131 from zlucas-netapp/zl-json-response

Author: zlucas-netapp

cmd/cmds.go

@@ -31,6 +31,7 @@ type StartCmd struct {
 	InspectTraffic bool   `default:"false" help:"Inspect MCP HTTP traffic"`
 	ReadOnly       bool   `default:"false" help:"Run MCP in read-only mode. This disables all tool calls that modify ONTAP state."`
 	Stateless      bool   `default:"false" help:"Run in stateless mode (no mcp-session-id header validation). Required when deploying behind proxies or gateways that don't preserve session headers, e.g. on-premises data gateways."`
+	JSONResponse   bool   `default:"false" help:"Respond with application/json instead of text/event-stream. Required when deploying behind proxies or gateways that do not relay SSE/chunked responses, e.g. on-premises data gateways."`
 }
 
 func (a *StartCmd) Run(cli *CLI) error {
@@ -50,6 +51,7 @@ func (a *StartCmd) Run(cli *CLI) error {
 		InspectTraffic: cli.Start.InspectTraffic,
 		ReadOnly:       cli.Start.ReadOnly,
 		Stateless:      cli.Start.Stateless,
+		JSONResponse:   cli.Start.JSONResponse,
 	}
 
 	app := server.NewApp(cfg, opts, logger)

docs/install.md

@@ -135,6 +135,7 @@ Some commonly used flags:
 |---|---|
 | `--read-only` | Disable all mutating operations. Only read-only tools are registered. |
 | `--stateless` | Disable mcp-session-id header validation. Required when deploying behind proxies or gateways that do not preserve session headers, e.g. on-premises data gateways. |
+| `--json-response` | Respond with application/json instead of text/event-stream. Required when deploying behind proxies or gateways that do not relay SSE/chunked responses, e.g. on-premises data gateways. |
 | `--inspect-traffic` | Log all MCP HTTP request and response bodies for debugging. |
 
 ## Next Steps

docs/tools.md

@@ -10,6 +10,8 @@ If you want to run the ONTAP MCP server in read-only mode, you can start the ser
 
 To run without mcp-session-id header validation (e.g. behind proxies that strip session headers), use the `--stateless` flag. See the [configuration documentation](install.md#configuration) for more details.
 
+To respond with `application/json` instead of `text/event-stream` (e.g. behind gateways that do not relay SSE/chunked responses), use the `--json-response` flag. See the [configuration documentation](install.md#configuration) for more details.
+
 ## API Discovery
 
 - `list_ontap_endpoints` (available when the API catalog is loaded)

server/server.go

@@ -37,6 +37,7 @@ type Options struct {
 	Port           int
 	ReadOnly       bool
 	Stateless      bool
+	JSONResponse   bool
 	TestHTTPClient *http.Client // Optional HTTP client for testing
 }
 
@@ -82,6 +83,9 @@ func (a *App) StartServer() {
 	if a.options.Stateless {
 		a.logger.Info("MCP server is running in stateless mode; mcp-session-id header validation is disabled")
 	}
+	if a.options.JSONResponse {
+		a.logger.Info("MCP server is responding with application/json instead of text/event-stream")
+	}
 	server := a.createMCPServer()
 	a.runHTTPServer(server)
 }
@@ -243,7 +247,7 @@ func (a *App) runHTTPServer(server *mcp.Server) {
 
 	handler = mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
 		return server
-	}, &mcp.StreamableHTTPOptions{Stateless: a.options.Stateless})
+	}, &mcp.StreamableHTTPOptions{Stateless: a.options.Stateless, JSONResponse: a.options.JSONResponse})
 
 	if a.options.InspectTraffic {
 		prevHandler := handler