feat(mcp): support local apps endpoint override

codex-rs/ext/mcp/src/lib.rs

@@ -5,10 +5,33 @@ use codex_extension_api::McpServerContribution;
 use codex_extension_api::McpServerContributionContext;
 use codex_extension_api::McpServerContributor;
 use codex_mcp::CODEX_APPS_MCP_SERVER_NAME;
+use codex_mcp::codex_apps_mcp_server_config;
 use codex_mcp::hosted_plugin_runtime_mcp_server_config;
 
 mod executor_plugin;
 
+const CODEX_APPS_MCP_BASE_URL_ENV_VAR: &str = "CODEX_APPS_MCP_BASE_URL";
+
+#[derive(Debug, Eq, PartialEq)]
+enum AppsMcpServerTarget<'a> {
+    HostedPluginRuntime(&'a str),
+    CodexApps(&'a str),
+}
+
+fn apps_mcp_server_target<'a>(
+    chatgpt_base_url: &'a str,
+    apps_mcp_base_url_override: Option<&'a str>,
+) -> AppsMcpServerTarget<'a> {
+    if let Some(apps_mcp_base_url) = apps_mcp_base_url_override
+        .map(str::trim)
+        .filter(|url| !url.is_empty())
+    {
+        return AppsMcpServerTarget::CodexApps(apps_mcp_base_url);
+    }
+
+    AppsMcpServerTarget::HostedPluginRuntime(chatgpt_base_url)
+}
+
 struct HostedPluginRuntimeExtension;
 
 impl McpServerContributor<Config> for HostedPluginRuntimeExtension {
@@ -27,17 +50,32 @@ impl McpServerContributor<Config> for HostedPluginRuntimeExtension {
                 return vec![McpServerContribution::Remove { name }];
             }
 
+            let apps_mcp_base_url_override = std::env::var(CODEX_APPS_MCP_BASE_URL_ENV_VAR).ok();
+            let apps_mcp_product_sku = config.apps_mcp_product_sku.as_deref();
+            let server_config = match apps_mcp_server_target(
+                &config.chatgpt_base_url,
+                apps_mcp_base_url_override.as_deref(),
+            ) {
+                AppsMcpServerTarget::HostedPluginRuntime(base_url) => {
+                    hosted_plugin_runtime_mcp_server_config(base_url, apps_mcp_product_sku)
+                }
+                AppsMcpServerTarget::CodexApps(base_url) => {
+                    codex_apps_mcp_server_config(base_url, apps_mcp_product_sku)
+                }
+            };
+
             vec![McpServerContribution::Set {
                 name,
-                config: Box::new(hosted_plugin_runtime_mcp_server_config(
-                    &config.chatgpt_base_url,
-                    config.apps_mcp_product_sku.as_deref(),
-                )),
+                config: Box::new(server_config),
             }]
         })
     }
 }
 
+#[cfg(test)]
+#[path = "lib_tests.rs"]
+mod tests;
+
 pub fn install(builder: &mut ExtensionRegistryBuilder<Config>) {
     builder.mcp_server_contributor(std::sync::Arc::new(HostedPluginRuntimeExtension));
 }

codex-rs/ext/mcp/src/lib_tests.rs

@@ -0,0 +1,31 @@
+use pretty_assertions::assert_eq;
+
+use super::AppsMcpServerTarget;
+use super::apps_mcp_server_target;
+
+#[test]
+fn default_uses_hosted_plugin_runtime() {
+    assert_eq!(
+        apps_mcp_server_target(
+            "https://chatgpt.com",
+            /*apps_mcp_base_url_override*/ None,
+        ),
+        AppsMcpServerTarget::HostedPluginRuntime("https://chatgpt.com"),
+    );
+}
+
+#[test]
+fn empty_override_uses_hosted_plugin_runtime() {
+    assert_eq!(
+        apps_mcp_server_target("https://chatgpt.com", Some("  ")),
+        AppsMcpServerTarget::HostedPluginRuntime("https://chatgpt.com"),
+    );
+}
+
+#[test]
+fn explicit_override_uses_local_codex_apps_endpoint() {
+    assert_eq!(
+        apps_mcp_server_target("https://chatgpt.com", Some("http://127.0.0.1:8061"),),
+        AppsMcpServerTarget::CodexApps("http://127.0.0.1:8061"),
+    );
+}

codex-rs/ext/mcp/tests/hosted_apps_mcp.rs

@@ -11,12 +11,14 @@ use codex_extension_api::McpServerContributionContext;
 use codex_extension_api::McpServerContributor;
 use codex_login::CodexAuth;
 use codex_mcp::CODEX_APPS_MCP_SERVER_NAME;
+use codex_mcp::codex_apps_mcp_server_config;
+use codex_mcp::hosted_plugin_runtime_mcp_server_config;
 use pretty_assertions::assert_eq;
 
 type TestResult = Result<(), Box<dyn std::error::Error>>;
 
 #[tokio::test]
-async fn contributes_hosted_plugin_runtime_without_an_executor() -> TestResult {
+async fn contributes_configured_apps_mcp_without_an_executor() -> TestResult {
     let codex_home = tempfile::tempdir()?;
     let config = ConfigBuilder::default()
         .codex_home(codex_home.path().to_path_buf())
@@ -34,11 +36,31 @@ async fn contributes_hosted_plugin_runtime_without_an_executor() -> TestResult {
     let server = servers
         .get(CODEX_APPS_MCP_SERVER_NAME)
         .and_then(|server| server.configured_config())
-        .ok_or("hosted plugin runtime should be contributed as a configured server")?;
+        .ok_or("Apps MCP should be contributed as a configured server")?;
     let McpServerTransportConfig::StreamableHttp { url, .. } = &server.transport else {
-        panic!("hosted plugin runtime should use streamable HTTP");
+        panic!("Apps MCP should use streamable HTTP");
     };
-    assert_eq!(url, "https://chatgpt.com/backend-api/ps/mcp");
+    let apps_mcp_base_url_override = std::env::var("CODEX_APPS_MCP_BASE_URL").ok();
+    let expected_config = match apps_mcp_base_url_override
+        .as_deref()
+        .map(str::trim)
+        .filter(|url| !url.is_empty())
+    {
+        Some(base_url) => {
+            codex_apps_mcp_server_config(base_url, /*apps_mcp_product_sku*/ None)
+        }
+        None => hosted_plugin_runtime_mcp_server_config(
+            "https://chatgpt.com",
+            /*apps_mcp_product_sku*/ None,
+        ),
+    };
+    let McpServerTransportConfig::StreamableHttp {
+        url: expected_url, ..
+    } = expected_config.transport
+    else {
+        panic!("expected Apps MCP config should use streamable HTTP");
+    };
+    assert_eq!(url, &expected_url);
 
     Ok(())
 }