Fix MCP tool listing for hyphenated server names (#16674)

Addresses #16671 and #14927

Problem: `mcpServerStatus/list` rebuilt MCP tool groups from sanitized
tool prefixes but looked them up by unsanitized server names, so
hyphenated servers rendered as having no tools in `/mcp`. This was
reported as a regression when the TUI switched to use the app server.

Solution: Build each server's tool map using the original server name's
sanitized prefix, include effective runtime MCP servers in the status
response, and add a regression test for hyphenated server names.

codex-rs/app-server/src/codex_message_processor.rs

@@ -248,7 +248,8 @@ use codex_login::run_login_server;
 use codex_mcp::mcp::auth::discover_supported_scopes;
 use codex_mcp::mcp::auth::resolve_oauth_scopes;
 use codex_mcp::mcp::collect_mcp_snapshot;
-use codex_mcp::mcp::group_tools_by_server;
+use codex_mcp::mcp::effective_mcp_servers;
+use codex_mcp::mcp::qualified_mcp_tool_name_prefix;
 use codex_models_manager::collaboration_mode_presets::CollaborationModesConfig;
 use codex_protocol::ThreadId;
 use codex_protocol::config_types::CollaborationMode;
@@ -5134,12 +5135,56 @@ impl CodexMessageProcessor {
         )
         .await;
 
-        let tools_by_server = group_tools_by_server(&snapshot.tools);
+        // Rebuild the tool list per original server name instead of using
+        // `group_tools_by_server()`: qualified tool names are sanitized for the
+        // Responses API, so a config key like `some-server` is encoded as the
+        // `mcp__some_server__` prefix. Matching with the original server name's
+        // sanitized prefix preserves `/mcp` output for hyphenated names.
+        let effective_servers = effective_mcp_servers(&mcp_config, auth.as_ref());
+        let mut sanitized_prefix_counts = HashMap::<String, usize>::new();
+        for name in effective_servers.keys() {
+            let prefix = qualified_mcp_tool_name_prefix(name);
+            *sanitized_prefix_counts.entry(prefix).or_default() += 1;
+        }
+        let tools_by_server = effective_servers
+            .keys()
+            .map(|name| {
+                let prefix = qualified_mcp_tool_name_prefix(name);
+                // If multiple server names normalize to the same prefix, the
+                // qualified tool namespace is ambiguous (for example
+                // `some-server` and `some_server` both become
+                // `mcp__some_server__`). In that case, avoid attributing the
+                // same tools to multiple servers.
+                let tools = if sanitized_prefix_counts
+                    .get(&prefix)
+                    .copied()
+                    .unwrap_or_default()
+                    == 1
+                {
+                    snapshot
+                        .tools
+                        .iter()
+                        .filter_map(|(qualified_name, tool)| {
+                            qualified_name
+                                .strip_prefix(&prefix)
+                                .map(|tool_name| (tool_name.to_string(), tool.clone()))
+                        })
+                        .collect::<HashMap<_, _>>()
+                } else {
+                    HashMap::new()
+                };
+                (name.clone(), tools)
+            })
+            .collect::<HashMap<_, _>>();
 
         let mut server_names: Vec<String> = config
             .mcp_servers
             .keys()
             .cloned()
+            // Include built-in/plugin MCP servers that are present in the
+            // effective runtime config even when they are not user-declared in
+            // `config.mcp_servers`.
+            .chain(effective_servers.keys().cloned())
             .chain(snapshot.auth_statuses.keys().cloned())
             .chain(snapshot.resources.keys().cloned())
             .chain(snapshot.resource_templates.keys().cloned())

codex-rs/app-server/tests/common/mcp_process.rs

@@ -45,6 +45,7 @@ use codex_app_server_protocol::JSONRPCMessage;
 use codex_app_server_protocol::JSONRPCNotification;
 use codex_app_server_protocol::JSONRPCRequest;
 use codex_app_server_protocol::JSONRPCResponse;
+use codex_app_server_protocol::ListMcpServerStatusParams;
 use codex_app_server_protocol::LoginAccountParams;
 use codex_app_server_protocol::MockExperimentalMethodParams;
 use codex_app_server_protocol::ModelListParams;
@@ -526,6 +527,15 @@ impl McpProcess {
         self.send_request("plugin/read", params).await
     }
 
+    /// Send an `mcpServerStatus/list` JSON-RPC request.
+    pub async fn send_list_mcp_server_status_request(
+        &mut self,
+        params: ListMcpServerStatusParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("mcpServerStatus/list", params).await
+    }
+
     /// Send a JSON-RPC request with raw params for protocol-level validation tests.
     pub async fn send_raw_request(
         &mut self,

codex-rs/app-server/tests/suite/v2/mcp_server_status.rs

@@ -0,0 +1,217 @@
+use std::borrow::Cow;
+use std::collections::BTreeMap;
+use std::collections::BTreeSet;
+use std::sync::Arc;
+use std::time::Duration;
+
+use anyhow::Result;
+use app_test_support::McpProcess;
+use app_test_support::create_mock_responses_server_sequence_unchecked;
+use app_test_support::to_response;
+use app_test_support::write_mock_responses_config_toml;
+use axum::Router;
+use codex_app_server_protocol::ListMcpServerStatusParams;
+use codex_app_server_protocol::ListMcpServerStatusResponse;
+use codex_app_server_protocol::RequestId;
+use pretty_assertions::assert_eq;
+use rmcp::handler::server::ServerHandler;
+use rmcp::model::JsonObject;
+use rmcp::model::ListToolsResult;
+use rmcp::model::ServerCapabilities;
+use rmcp::model::ServerInfo;
+use rmcp::model::Tool;
+use rmcp::model::ToolAnnotations;
+use rmcp::transport::StreamableHttpServerConfig;
+use rmcp::transport::StreamableHttpService;
+use rmcp::transport::streamable_http_server::session::local::LocalSessionManager;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::net::TcpListener;
+use tokio::task::JoinHandle;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[tokio::test]
+async fn mcp_server_status_list_returns_tools_for_hyphenated_server_names() -> Result<()> {
+    let server = create_mock_responses_server_sequence_unchecked(Vec::new()).await;
+    let (mcp_server_url, mcp_server_handle) = start_mcp_server("lookup").await?;
+    let codex_home = TempDir::new()?;
+    write_mock_responses_config_toml(
+        codex_home.path(),
+        &server.uri(),
+        &BTreeMap::new(),
+        /*auto_compact_limit*/ 1024,
+        /*requires_openai_auth*/ None,
+        "mock_provider",
+        "compact",
+    )?;
+
+    let config_path = codex_home.path().join("config.toml");
+    let mut config_toml = std::fs::read_to_string(&config_path)?;
+    config_toml.push_str(&format!(
+        r#"
+[mcp_servers.some-server]
+url = "{mcp_server_url}/mcp"
+"#
+    ));
+    std::fs::write(config_path, config_toml)?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let request_id = mcp
+        .send_list_mcp_server_status_request(ListMcpServerStatusParams {
+            cursor: None,
+            limit: None,
+        })
+        .await?;
+    let response = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await??;
+    let response: ListMcpServerStatusResponse = to_response(response)?;
+
+    assert_eq!(response.next_cursor, None);
+    assert_eq!(response.data.len(), 1);
+    let status = &response.data[0];
+    assert_eq!(status.name, "some-server");
+    assert_eq!(
+        status.tools.keys().cloned().collect::<BTreeSet<_>>(),
+        BTreeSet::from(["lookup".to_string()])
+    );
+
+    mcp_server_handle.abort();
+    let _ = mcp_server_handle.await;
+
+    Ok(())
+}
+
+#[derive(Clone)]
+struct McpStatusServer {
+    tool_name: Arc<String>,
+}
+
+impl ServerHandler for McpStatusServer {
+    fn get_info(&self) -> ServerInfo {
+        ServerInfo {
+            capabilities: ServerCapabilities::builder().enable_tools().build(),
+            ..ServerInfo::default()
+        }
+    }
+
+    async fn list_tools(
+        &self,
+        _request: Option<rmcp::model::PaginatedRequestParams>,
+        _context: rmcp::service::RequestContext<rmcp::service::RoleServer>,
+    ) -> Result<ListToolsResult, rmcp::ErrorData> {
+        let input_schema: JsonObject = serde_json::from_value(json!({
+            "type": "object",
+            "additionalProperties": false
+        }))
+        .map_err(|err| rmcp::ErrorData::internal_error(err.to_string(), None))?;
+
+        let mut tool = Tool::new(
+            Cow::Owned(self.tool_name.as_ref().clone()),
+            Cow::Borrowed("Look up test data."),
+            Arc::new(input_schema),
+        );
+        tool.annotations = Some(ToolAnnotations::new().read_only(true));
+
+        Ok(ListToolsResult {
+            tools: vec![tool],
+            next_cursor: None,
+            meta: None,
+        })
+    }
+}
+
+#[tokio::test]
+async fn mcp_server_status_list_does_not_duplicate_tools_for_sanitized_name_collisions()
+-> Result<()> {
+    let server = create_mock_responses_server_sequence_unchecked(Vec::new()).await;
+    let (dash_server_url, dash_server_handle) = start_mcp_server("dash_lookup").await?;
+    let (underscore_server_url, underscore_server_handle) =
+        start_mcp_server("underscore_lookup").await?;
+    let codex_home = TempDir::new()?;
+    write_mock_responses_config_toml(
+        codex_home.path(),
+        &server.uri(),
+        &BTreeMap::new(),
+        /*auto_compact_limit*/ 1024,
+        /*requires_openai_auth*/ None,
+        "mock_provider",
+        "compact",
+    )?;
+
+    let config_path = codex_home.path().join("config.toml");
+    let mut config_toml = std::fs::read_to_string(&config_path)?;
+    config_toml.push_str(&format!(
+        r#"
+[mcp_servers.some-server]
+url = "{dash_server_url}/mcp"
+
+[mcp_servers.some_server]
+url = "{underscore_server_url}/mcp"
+"#
+    ));
+    std::fs::write(config_path, config_toml)?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let request_id = mcp
+        .send_list_mcp_server_status_request(ListMcpServerStatusParams {
+            cursor: None,
+            limit: None,
+        })
+        .await?;
+    let response = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await??;
+    let response: ListMcpServerStatusResponse = to_response(response)?;
+
+    assert_eq!(response.next_cursor, None);
+    assert_eq!(response.data.len(), 2);
+    let status_tools = response
+        .data
+        .iter()
+        .map(|status| (status.name.as_str(), status.tools.keys().count()))
+        .collect::<BTreeMap<_, _>>();
+    assert_eq!(
+        status_tools,
+        BTreeMap::from([("some-server", 0), ("some_server", 0)])
+    );
+
+    dash_server_handle.abort();
+    let _ = dash_server_handle.await;
+    underscore_server_handle.abort();
+    let _ = underscore_server_handle.await;
+
+    Ok(())
+}
+
+async fn start_mcp_server(tool_name: &str) -> Result<(String, JoinHandle<()>)> {
+    let listener = TcpListener::bind("127.0.0.1:0").await?;
+    let addr = listener.local_addr()?;
+    let tool_name = Arc::new(tool_name.to_string());
+    let mcp_service = StreamableHttpService::new(
+        move || {
+            Ok(McpStatusServer {
+                tool_name: Arc::clone(&tool_name),
+            })
+        },
+        Arc::new(LocalSessionManager::default()),
+        StreamableHttpServerConfig::default(),
+    );
+    let router = Router::new().nest_service("/mcp", mcp_service);
+
+    let handle = tokio::spawn(async move {
+        let _ = axum::serve(listener, router).await;
+    });
+
+    Ok((format!("http://{addr}"), handle))
+}

codex-rs/app-server/tests/suite/v2/mod.rs

@@ -15,6 +15,7 @@ mod experimental_feature_list;
 mod fs;
 mod initialize;
 mod mcp_server_elicitation;
+mod mcp_server_status;
 mod model_list;
 mod output_schema;
 mod plan_item;