feat: MCP UI proxy to goose-server #5749

alexhancock · 2025-11-14T21:48:00Z

Moves the mcp ui proxy from desktop ts -> goosed

Copilot

Pull Request Overview

This PR migrates the MCP UI proxy functionality from a local Electron-managed HTTP server to a centralized endpoint on the goose-server. The changes remove complex client-side proxy security infrastructure (token generation, header injection, WebContents whitelisting) in favor of a simpler server-side implementation.

Key changes:

Removes local proxy server initialization and IPC handlers from the Electron desktop app
Updates the MCP UI renderer to fetch proxy URL from goose-server instead of Electron main process
Adds /mcp-ui-proxy endpoint to goose-server with auth bypass

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
ui/desktop/src/preload.ts	Removes getMcpUIProxyUrl IPC API definition
ui/desktop/src/main.ts	Removes proxy initialization call
ui/desktop/src/components/MCPUIResourceRenderer.tsx	Updates to construct proxy URL from goosed host/port
ui/desktop/src/api/types.gen.ts	Generated TypeScript types for new endpoint
ui/desktop/src/api/sdk.gen.ts	Generated SDK client for new endpoint
ui/desktop/openapi.json	OpenAPI schema update for new endpoint
crates/goose-server/src/routes/mod.rs	Registers new mcp_ui_proxy route module
crates/goose-server/src/openapi.rs	Registers new endpoint in OpenAPI docs
crates/goose-server/src/auth.rs	Bypasses authentication for /mcp-ui-proxy

Copilot · 2025-11-14T21:50:27Z

crates/goose-server/src/routes/mod.rs

 pub mod audio;
 pub mod config_management;
 pub mod errors;
+pub mod mcp_ui_proxy;


The mcp_ui_proxy.rs module file doesn't exist yet. This will cause a compilation error.

Copilot · 2025-11-14T21:50:27Z

crates/goose-server/src/auth.rs

    next: Next,
 ) -> Result<Response, StatusCode> {
-    if request.uri().path() == "/status" {
+    if request.uri().path() == "/status" || request.uri().path() == "/mcp-ui-proxy" {


Bypassing authentication for /mcp-ui-proxy removes the security protections from the original implementation (token validation, origin checks, WebContents whitelisting). This allows unauthenticated access to MCP UI resources. Consider requiring the X-Secret-Key header or document why this endpoint must be public.

Suggested change

if request.uri().path() == "/status" || request.uri().path() == "/mcp-ui-proxy" {

if request.uri().path() == "/status" {

I support simplifying the complexity of security protections in the Node implementation. I think our goal should be to prevent access to the route outside of Goose (like directly in-browser and/or via CURL).

aharvard · 2025-11-17T14:56:56Z

crates/goose-server/src/routes/mcp_ui_proxy.rs

+    Router,
+};
+
+const MCP_UI_PROXY_HTML: &str = r#"<!doctype html>


To make this easier to maintain, can we keep this HTML as a standalone file and inline it like we do in the autovisualiser mod.rs?

Copilot

Pull Request Overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 4 comments.

Copilot · 2025-11-17T15:51:33Z

crates/goose-server/src/routes/mcp_ui_proxy.rs

+    axum::extract::State(secret_key): axum::extract::State<String>,
+    Query(params): Query<ProxyQuery>,
+) -> Response {
+    if params.secret != secret_key {


Timing attack vulnerability: string comparison using != operator is not constant-time. An attacker could use timing differences to guess the secret key character by character. Use a constant-time comparison function instead, such as subtle::ConstantTimeEq from the subtle crate.

Copilot · 2025-11-17T15:51:33Z

ui/desktop/src/components/MCPUIResourceRenderer.tsx

+        const baseUrl = await window.electron.getGoosedHostPort();
+        const secretKey = await window.electron.getSecretKey();
+        if (baseUrl && secretKey) {
+          setProxyUrl(`${baseUrl}/mcp-ui-proxy?secret=${encodeURIComponent(secretKey)}`);


Security exposure: the secret key is exposed in the URL query parameter, which can be logged in browser history, server logs, and referrer headers. Consider using a POST request with the secret in the request body, or implementing a session-based approach where the authentication happens separately from the proxy URL.

Suggested change

setProxyUrl(`${baseUrl}/mcp-ui-proxy?secret=${encodeURIComponent(secretKey)}`);

setProxyUrl(`${baseUrl}/mcp-ui-proxy`);

Copilot · 2025-11-17T15:51:34Z

crates/goose-server/src/auth.rs

    next: Next,
 ) -> Result<Response, StatusCode> {
-    if request.uri().path() == "/status" {
+    if request.uri().path() == "/status" || request.uri().path() == "/mcp-ui-proxy" {


Authentication bypass: /mcp-ui-proxy is excluded from the global auth middleware check (line 13), but performs its own authentication using query parameters. This creates an inconsistent security model. If the query parameter check fails or is bypassed, the endpoint becomes publicly accessible. Consider either: (1) keeping /mcp-ui-proxy in the middleware and moving secret validation there, or (2) ensuring the endpoint's authentication is robust enough to stand alone.

Suggested change

if request.uri().path() == "/status" || request.uri().path() == "/mcp-ui-proxy" {

if request.uri().path() == "/status" {

Copilot · 2025-11-17T15:51:34Z

crates/goose-server/src/routes/mcp_ui_proxy.rs

+    -->
+    <meta 
+      http-equiv="Content-Security-Policy" 
+      content="default-src 'self'; script-src * 'wasm-unsafe-eval' 'unsafe-inline' 'unsafe-eval' blob:; style-src * 'unsafe-inline'; font-src *; connect-src *; frame-src *; media-src *; base-uri 'self'; upgrade-insecure-requests"/>


Security risk: the CSP includes 'unsafe-eval' in script-src, which allows eval(), new Function(), and similar dangerous operations. This significantly weakens the CSP's protection against XSS attacks. Unless absolutely required for MCP-UI functionality, consider removing 'unsafe-eval' and using safer alternatives like 'wasm-unsafe-eval' (which you already have) for WebAssembly.

Suggested change

content="default-src 'self'; script-src * 'wasm-unsafe-eval' 'unsafe-inline' 'unsafe-eval' blob:; style-src * 'unsafe-inline'; font-src *; connect-src *; frame-src *; media-src *; base-uri 'self'; upgrade-insecure-requests"/>

content="default-src 'self'; script-src * 'wasm-unsafe-eval' 'unsafe-inline' blob:; style-src * 'unsafe-inline'; font-src *; connect-src *; frame-src *; media-src *; base-uri 'self'; upgrade-insecure-requests"/>

aharvard

LGTM, thanks!

alexhancock requested review from aharvard and Copilot November 14, 2025 21:48

Copilot started reviewing on behalf of alexhancock November 14, 2025 21:48 View session

alexhancock marked this pull request as draft November 14, 2025 21:48

Copilot finished reviewing on behalf of alexhancock November 14, 2025 21:49

Copilot AI reviewed Nov 14, 2025

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alexhancock force-pushed the feat/mcp-ui-improvements-rust-server-goosed branch from 5d2cd63 to a7770d0 Compare November 14, 2025 22:41

aharvard reviewed Nov 17, 2025

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alexhancock marked this pull request as ready for review November 17, 2025 15:48

alexhancock requested review from aharvard and Copilot November 17, 2025 15:48

Copilot started reviewing on behalf of alexhancock November 17, 2025 15:48 View session

Copilot finished reviewing on behalf of alexhancock November 17, 2025 15:50

Copilot AI reviewed Nov 17, 2025

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feat: MCP UI proxy to goose-server

20c8740

alexhancock force-pushed the feat/mcp-ui-improvements-rust-server-goosed branch from 31c6b36 to 20c8740 Compare November 17, 2025 19:53

aharvard approved these changes Nov 17, 2025

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aharvard merged commit b6740fb into feat/mcp-ui-improvements Nov 17, 2025
4 checks passed

aharvard mentioned this pull request Nov 17, 2025

[MCP-UI] Proxy and Better Message Handling #5487

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alexhancock commented Nov 14, 2025 •

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	if request.uri().path() == "/status" \|\| request.uri().path() == "/mcp-ui-proxy" {
	if request.uri().path() == "/status" {

	setProxyUrl(`${baseUrl}/mcp-ui-proxy?secret=${encodeURIComponent(secretKey)}`);
	setProxyUrl(`${baseUrl}/mcp-ui-proxy`);

	content="default-src 'self'; script-src * 'wasm-unsafe-eval' 'unsafe-inline' 'unsafe-eval' blob:; style-src * 'unsafe-inline'; font-src ; connect-src ; frame-src ; media-src ; base-uri 'self'; upgrade-insecure-requests"/>
	content="default-src 'self'; script-src * 'wasm-unsafe-eval' 'unsafe-inline' blob:; style-src * 'unsafe-inline'; font-src ; connect-src ; frame-src ; media-src ; base-uri 'self'; upgrade-insecure-requests"/>

feat: MCP UI proxy to goose-server #5749

feat: MCP UI proxy to goose-server #5749

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alexhancock commented Nov 14, 2025 •

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