fix: separate codex mcp into codex mcp-server and codex app-server (#4471)

This is a very large PR with some non-backwards-compatible changes.

Historically, `codex mcp` (or `codex mcp serve`) started a JSON-RPC-ish
server that had two overlapping responsibilities:

- Running an MCP server, providing some basic tool calls.
- Running the app server used to power experiences such as the VS Code
extension.

This PR aims to separate these into distinct concepts:

- `codex mcp-server` for the MCP server
- `codex app-server` for the "application server"

Note `codex mcp` still exists because it already has its own subcommands
for MCP management (`list`, `add`, etc.)

The MCP logic continues to live in `codex-rs/mcp-server` whereas the
refactored app server logic is in the new `codex-rs/app-server` folder.
Note that most of the existing integration tests in
`codex-rs/mcp-server/tests/suite` were actually for the app server, so
all the tests have been moved with the exception of
`codex-rs/mcp-server/tests/suite/mod.rs`.

Because this is already a large diff, I tried not to change more than I
had to, so `codex-rs/app-server/tests/common/mcp_process.rs` still uses
the name `McpProcess` for now, but I will do some mechanical renamings
to things like `AppServer` in subsequent PRs.

While `mcp-server` and `app-server` share some overlapping functionality
(like reading streams of JSONL and dispatching based on message types)
and some differences (completely different message types), I ended up
doing a bit of copypasta between the two crates, as both have somewhat
similar `message_processor.rs` and `outgoing_message.rs` files for now,
though I expect them to diverge more in the near future.

One material change is that of the initialize handshake for `codex
app-server`, as we no longer use the MCP types for that handshake.
Instead, we update `codex-rs/protocol/src/mcp_protocol.rs` to add an
`Initialize` variant to `ClientRequest`, which takes the `ClientInfo`
object we need to update the `USER_AGENT_SUFFIX` in
`codex-rs/app-server/src/message_processor.rs`.

One other material change is in
`codex-rs/app-server/src/codex_message_processor.rs` where I eliminated
a use of the `send_event_as_notification()` method I am generally trying
to deprecate (because it blindly maps an `EventMsg` into a
`JSONNotification`) in favor of `send_server_notification()`, which
takes a `ServerNotification`, as that is intended to be a custom enum of
all notification types supported by the app server. So to make this
update, I had to introduce a new variant of `ServerNotification`,
`SessionConfigured`, which is a non-backwards compatible change with the
old `codex mcp`, and clients will have to be updated after the next
release that contains this PR. Note that
`codex-rs/app-server/tests/suite/list_resume.rs` also had to be update
to reflect this change.

I introduced `codex-rs/utils/json-to-toml/src/lib.rs` as a small utility
crate to avoid some of the copying between `mcp-server` and
`app-server`.

codex-rs/app-server/tests/all.rs

@@ -0,0 +1,3 @@
+// Single integration test binary that aggregates all test modules.
+// The submodules live in `tests/suite/`.
+mod suite;

codex-rs/app-server/tests/common/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+edition = "2024"
+name = "app_test_support"
+version = { workspace = true }
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+anyhow = { workspace = true }
+assert_cmd = { workspace = true }
+codex-protocol = { workspace = true }
+mcp-types = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tokio = { workspace = true, features = [
+    "io-std",
+    "macros",
+    "process",
+    "rt-multi-thread",
+] }
+wiremock = { workspace = true }

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

@@ -0,0 +1,17 @@
+mod mcp_process;
+mod mock_model_server;
+mod responses;
+
+pub use mcp_process::McpProcess;
+use mcp_types::JSONRPCResponse;
+pub use mock_model_server::create_mock_chat_completions_server;
+pub use responses::create_apply_patch_sse_response;
+pub use responses::create_final_assistant_message_sse_response;
+pub use responses::create_shell_sse_response;
+use serde::de::DeserializeOwned;
+
+pub fn to_response<T: DeserializeOwned>(response: JSONRPCResponse) -> anyhow::Result<T> {
+    let value = serde_json::to_value(response.result)?;
+    let codex_response = serde_json::from_value(value)?;
+    Ok(codex_response)
+}

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

@@ -0,0 +1,477 @@
+use std::path::Path;
+use std::process::Stdio;
+use std::sync::atomic::AtomicI64;
+use std::sync::atomic::Ordering;
+use tokio::io::AsyncBufReadExt;
+use tokio::io::AsyncWriteExt;
+use tokio::io::BufReader;
+use tokio::process::Child;
+use tokio::process::ChildStdin;
+use tokio::process::ChildStdout;
+
+use anyhow::Context;
+use assert_cmd::prelude::*;
+use codex_protocol::mcp_protocol::AddConversationListenerParams;
+use codex_protocol::mcp_protocol::ArchiveConversationParams;
+use codex_protocol::mcp_protocol::CancelLoginChatGptParams;
+use codex_protocol::mcp_protocol::ClientInfo;
+use codex_protocol::mcp_protocol::ClientNotification;
+use codex_protocol::mcp_protocol::GetAuthStatusParams;
+use codex_protocol::mcp_protocol::InitializeParams;
+use codex_protocol::mcp_protocol::InterruptConversationParams;
+use codex_protocol::mcp_protocol::ListConversationsParams;
+use codex_protocol::mcp_protocol::LoginApiKeyParams;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::RemoveConversationListenerParams;
+use codex_protocol::mcp_protocol::ResumeConversationParams;
+use codex_protocol::mcp_protocol::SendUserMessageParams;
+use codex_protocol::mcp_protocol::SendUserTurnParams;
+use codex_protocol::mcp_protocol::SetDefaultModelParams;
+
+use mcp_types::JSONRPC_VERSION;
+use mcp_types::JSONRPCMessage;
+use mcp_types::JSONRPCNotification;
+use mcp_types::JSONRPCRequest;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use std::process::Command as StdCommand;
+use tokio::process::Command;
+
+pub struct McpProcess {
+    next_request_id: AtomicI64,
+    /// Retain this child process until the client is dropped. The Tokio runtime
+    /// will make a "best effort" to reap the process after it exits, but it is
+    /// not a guarantee. See the `kill_on_drop` documentation for details.
+    #[allow(dead_code)]
+    process: Child,
+    stdin: ChildStdin,
+    stdout: BufReader<ChildStdout>,
+}
+
+impl McpProcess {
+    pub async fn new(codex_home: &Path) -> anyhow::Result<Self> {
+        Self::new_with_env(codex_home, &[]).await
+    }
+
+    /// Creates a new MCP process, allowing tests to override or remove
+    /// specific environment variables for the child process only.
+    ///
+    /// Pass a tuple of (key, Some(value)) to set/override, or (key, None) to
+    /// remove a variable from the child's environment.
+    pub async fn new_with_env(
+        codex_home: &Path,
+        env_overrides: &[(&str, Option<&str>)],
+    ) -> anyhow::Result<Self> {
+        // Use assert_cmd to locate the binary path and then switch to tokio::process::Command
+        let std_cmd = StdCommand::cargo_bin("codex-app-server")
+            .context("should find binary for codex-mcp-server")?;
+
+        let program = std_cmd.get_program().to_owned();
+
+        let mut cmd = Command::new(program);
+
+        cmd.stdin(Stdio::piped());
+        cmd.stdout(Stdio::piped());
+        cmd.stderr(Stdio::piped());
+        cmd.env("CODEX_HOME", codex_home);
+        cmd.env("RUST_LOG", "debug");
+
+        for (k, v) in env_overrides {
+            match v {
+                Some(val) => {
+                    cmd.env(k, val);
+                }
+                None => {
+                    cmd.env_remove(k);
+                }
+            }
+        }
+
+        let mut process = cmd
+            .kill_on_drop(true)
+            .spawn()
+            .context("codex-mcp-server proc should start")?;
+        let stdin = process
+            .stdin
+            .take()
+            .ok_or_else(|| anyhow::format_err!("mcp should have stdin fd"))?;
+        let stdout = process
+            .stdout
+            .take()
+            .ok_or_else(|| anyhow::format_err!("mcp should have stdout fd"))?;
+        let stdout = BufReader::new(stdout);
+
+        // Forward child's stderr to our stderr so failures are visible even
+        // when stdout/stderr are captured by the test harness.
+        if let Some(stderr) = process.stderr.take() {
+            let mut stderr_reader = BufReader::new(stderr).lines();
+            tokio::spawn(async move {
+                while let Ok(Some(line)) = stderr_reader.next_line().await {
+                    eprintln!("[mcp stderr] {line}");
+                }
+            });
+        }
+        Ok(Self {
+            next_request_id: AtomicI64::new(0),
+            process,
+            stdin,
+            stdout,
+        })
+    }
+
+    /// Performs the initialization handshake with the MCP server.
+    pub async fn initialize(&mut self) -> anyhow::Result<()> {
+        let params = Some(serde_json::to_value(InitializeParams {
+            client_info: ClientInfo {
+                name: "codex-app-server-tests".to_string(),
+                title: None,
+                version: "0.1.0".to_string(),
+            },
+        })?);
+        let req_id = self.send_request("initialize", params).await?;
+        let initialized = self.read_jsonrpc_message().await?;
+        let JSONRPCMessage::Response(response) = initialized else {
+            unreachable!("expected JSONRPCMessage::Response for initialize, got {initialized:?}");
+        };
+        if response.id != RequestId::Integer(req_id) {
+            anyhow::bail!(
+                "initialize response id mismatch: expected {}, got {:?}",
+                req_id,
+                response.id
+            );
+        }
+
+        // Send notifications/initialized to ack the response.
+        self.send_notification(ClientNotification::Initialized)
+            .await?;
+
+        Ok(())
+    }
+
+    /// Send a `newConversation` JSON-RPC request.
+    pub async fn send_new_conversation_request(
+        &mut self,
+        params: NewConversationParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("newConversation", params).await
+    }
+
+    /// Send an `archiveConversation` JSON-RPC request.
+    pub async fn send_archive_conversation_request(
+        &mut self,
+        params: ArchiveConversationParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("archiveConversation", params).await
+    }
+
+    /// Send an `addConversationListener` JSON-RPC request.
+    pub async fn send_add_conversation_listener_request(
+        &mut self,
+        params: AddConversationListenerParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("addConversationListener", params).await
+    }
+
+    /// Send a `sendUserMessage` JSON-RPC request with a single text item.
+    pub async fn send_send_user_message_request(
+        &mut self,
+        params: SendUserMessageParams,
+    ) -> anyhow::Result<i64> {
+        // Wire format expects variants in camelCase; text item uses external tagging.
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("sendUserMessage", params).await
+    }
+
+    /// Send a `removeConversationListener` JSON-RPC request.
+    pub async fn send_remove_conversation_listener_request(
+        &mut self,
+        params: RemoveConversationListenerParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("removeConversationListener", params)
+            .await
+    }
+
+    /// Send a `sendUserTurn` JSON-RPC request.
+    pub async fn send_send_user_turn_request(
+        &mut self,
+        params: SendUserTurnParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("sendUserTurn", params).await
+    }
+
+    /// Send a `interruptConversation` JSON-RPC request.
+    pub async fn send_interrupt_conversation_request(
+        &mut self,
+        params: InterruptConversationParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("interruptConversation", params).await
+    }
+
+    /// Send a `getAuthStatus` JSON-RPC request.
+    pub async fn send_get_auth_status_request(
+        &mut self,
+        params: GetAuthStatusParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("getAuthStatus", params).await
+    }
+
+    /// Send a `getUserSavedConfig` JSON-RPC request.
+    pub async fn send_get_user_saved_config_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("getUserSavedConfig", None).await
+    }
+
+    /// Send a `getUserAgent` JSON-RPC request.
+    pub async fn send_get_user_agent_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("getUserAgent", None).await
+    }
+
+    /// Send a `userInfo` JSON-RPC request.
+    pub async fn send_user_info_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("userInfo", None).await
+    }
+
+    /// Send a `setDefaultModel` JSON-RPC request.
+    pub async fn send_set_default_model_request(
+        &mut self,
+        params: SetDefaultModelParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("setDefaultModel", params).await
+    }
+
+    /// Send a `listConversations` JSON-RPC request.
+    pub async fn send_list_conversations_request(
+        &mut self,
+        params: ListConversationsParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("listConversations", params).await
+    }
+
+    /// Send a `resumeConversation` JSON-RPC request.
+    pub async fn send_resume_conversation_request(
+        &mut self,
+        params: ResumeConversationParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("resumeConversation", params).await
+    }
+
+    /// Send a `loginApiKey` JSON-RPC request.
+    pub async fn send_login_api_key_request(
+        &mut self,
+        params: LoginApiKeyParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("loginApiKey", params).await
+    }
+
+    /// Send a `loginChatGpt` JSON-RPC request.
+    pub async fn send_login_chat_gpt_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("loginChatGpt", None).await
+    }
+
+    /// Send a `cancelLoginChatGpt` JSON-RPC request.
+    pub async fn send_cancel_login_chat_gpt_request(
+        &mut self,
+        params: CancelLoginChatGptParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("cancelLoginChatGpt", params).await
+    }
+
+    /// Send a `logoutChatGpt` JSON-RPC request.
+    pub async fn send_logout_chat_gpt_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("logoutChatGpt", None).await
+    }
+
+    /// Send a `fuzzyFileSearch` JSON-RPC request.
+    pub async fn send_fuzzy_file_search_request(
+        &mut self,
+        query: &str,
+        roots: Vec<String>,
+        cancellation_token: Option<String>,
+    ) -> anyhow::Result<i64> {
+        let mut params = serde_json::json!({
+            "query": query,
+            "roots": roots,
+        });
+        if let Some(token) = cancellation_token {
+            params["cancellationToken"] = serde_json::json!(token);
+        }
+        self.send_request("fuzzyFileSearch", Some(params)).await
+    }
+
+    async fn send_request(
+        &mut self,
+        method: &str,
+        params: Option<serde_json::Value>,
+    ) -> anyhow::Result<i64> {
+        let request_id = self.next_request_id.fetch_add(1, Ordering::Relaxed);
+
+        let message = JSONRPCMessage::Request(JSONRPCRequest {
+            jsonrpc: JSONRPC_VERSION.into(),
+            id: RequestId::Integer(request_id),
+            method: method.to_string(),
+            params,
+        });
+        self.send_jsonrpc_message(message).await?;
+        Ok(request_id)
+    }
+
+    pub async fn send_response(
+        &mut self,
+        id: RequestId,
+        result: serde_json::Value,
+    ) -> anyhow::Result<()> {
+        self.send_jsonrpc_message(JSONRPCMessage::Response(JSONRPCResponse {
+            jsonrpc: JSONRPC_VERSION.into(),
+            id,
+            result,
+        }))
+        .await
+    }
+
+    pub async fn send_notification(
+        &mut self,
+        notification: ClientNotification,
+    ) -> anyhow::Result<()> {
+        let value = serde_json::to_value(notification)?;
+        self.send_jsonrpc_message(JSONRPCMessage::Notification(JSONRPCNotification {
+            jsonrpc: JSONRPC_VERSION.into(),
+            method: value
+                .get("method")
+                .and_then(|m| m.as_str())
+                .ok_or_else(|| anyhow::format_err!("notification missing method field"))?
+                .to_string(),
+            params: value.get("params").cloned(),
+        }))
+        .await
+    }
+
+    async fn send_jsonrpc_message(&mut self, message: JSONRPCMessage) -> anyhow::Result<()> {
+        eprintln!("writing message to stdin: {message:?}");
+        let payload = serde_json::to_string(&message)?;
+        self.stdin.write_all(payload.as_bytes()).await?;
+        self.stdin.write_all(b"\n").await?;
+        self.stdin.flush().await?;
+        Ok(())
+    }
+
+    async fn read_jsonrpc_message(&mut self) -> anyhow::Result<JSONRPCMessage> {
+        let mut line = String::new();
+        self.stdout.read_line(&mut line).await?;
+        let message = serde_json::from_str::<JSONRPCMessage>(&line)?;
+        eprintln!("read message from stdout: {message:?}");
+        Ok(message)
+    }
+
+    pub async fn read_stream_until_request_message(&mut self) -> anyhow::Result<JSONRPCRequest> {
+        eprintln!("in read_stream_until_request_message()");
+
+        loop {
+            let message = self.read_jsonrpc_message().await?;
+
+            match message {
+                JSONRPCMessage::Notification(_) => {
+                    eprintln!("notification: {message:?}");
+                }
+                JSONRPCMessage::Request(jsonrpc_request) => {
+                    return Ok(jsonrpc_request);
+                }
+                JSONRPCMessage::Error(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Error: {message:?}");
+                }
+                JSONRPCMessage::Response(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Response: {message:?}");
+                }
+            }
+        }
+    }
+
+    pub async fn read_stream_until_response_message(
+        &mut self,
+        request_id: RequestId,
+    ) -> anyhow::Result<JSONRPCResponse> {
+        eprintln!("in read_stream_until_response_message({request_id:?})");
+
+        loop {
+            let message = self.read_jsonrpc_message().await?;
+            match message {
+                JSONRPCMessage::Notification(_) => {
+                    eprintln!("notification: {message:?}");
+                }
+                JSONRPCMessage::Request(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Request: {message:?}");
+                }
+                JSONRPCMessage::Error(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Error: {message:?}");
+                }
+                JSONRPCMessage::Response(jsonrpc_response) => {
+                    if jsonrpc_response.id == request_id {
+                        return Ok(jsonrpc_response);
+                    }
+                }
+            }
+        }
+    }
+
+    pub async fn read_stream_until_error_message(
+        &mut self,
+        request_id: RequestId,
+    ) -> anyhow::Result<mcp_types::JSONRPCError> {
+        loop {
+            let message = self.read_jsonrpc_message().await?;
+            match message {
+                JSONRPCMessage::Notification(_) => {
+                    eprintln!("notification: {message:?}");
+                }
+                JSONRPCMessage::Request(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Request: {message:?}");
+                }
+                JSONRPCMessage::Response(_) => {
+                    // Keep scanning; we're waiting for an error with matching id.
+                }
+                JSONRPCMessage::Error(err) => {
+                    if err.id == request_id {
+                        return Ok(err);
+                    }
+                }
+            }
+        }
+    }
+
+    pub async fn read_stream_until_notification_message(
+        &mut self,
+        method: &str,
+    ) -> anyhow::Result<JSONRPCNotification> {
+        eprintln!("in read_stream_until_notification_message({method})");
+
+        loop {
+            let message = self.read_jsonrpc_message().await?;
+            match message {
+                JSONRPCMessage::Notification(notification) => {
+                    if notification.method == method {
+                        return Ok(notification);
+                    }
+                }
+                JSONRPCMessage::Request(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Request: {message:?}");
+                }
+                JSONRPCMessage::Error(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Error: {message:?}");
+                }
+                JSONRPCMessage::Response(_) => {
+                    anyhow::bail!("unexpected JSONRPCMessage::Response: {message:?}");
+                }
+            }
+        }
+    }
+}

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

@@ -0,0 +1,47 @@
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+
+use wiremock::Mock;
+use wiremock::MockServer;
+use wiremock::Respond;
+use wiremock::ResponseTemplate;
+use wiremock::matchers::method;
+use wiremock::matchers::path;
+
+/// Create a mock server that will provide the responses, in order, for
+/// requests to the `/v1/chat/completions` endpoint.
+pub async fn create_mock_chat_completions_server(responses: Vec<String>) -> MockServer {
+    let server = MockServer::start().await;
+
+    let num_calls = responses.len();
+    let seq_responder = SeqResponder {
+        num_calls: AtomicUsize::new(0),
+        responses,
+    };
+
+    Mock::given(method("POST"))
+        .and(path("/v1/chat/completions"))
+        .respond_with(seq_responder)
+        .expect(num_calls as u64)
+        .mount(&server)
+        .await;
+
+    server
+}
+
+struct SeqResponder {
+    num_calls: AtomicUsize,
+    responses: Vec<String>,
+}
+
+impl Respond for SeqResponder {
+    fn respond(&self, _: &wiremock::Request) -> ResponseTemplate {
+        let call_num = self.num_calls.fetch_add(1, Ordering::SeqCst);
+        match self.responses.get(call_num) {
+            Some(response) => ResponseTemplate::new(200)
+                .insert_header("content-type", "text/event-stream")
+                .set_body_raw(response.clone(), "text/event-stream"),
+            None => panic!("no response for {call_num}"),
+        }
+    }
+}

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

@@ -0,0 +1,95 @@
+use serde_json::json;
+use std::path::Path;
+
+pub fn create_shell_sse_response(
+    command: Vec<String>,
+    workdir: Option<&Path>,
+    timeout_ms: Option<u64>,
+    call_id: &str,
+) -> anyhow::Result<String> {
+    // The `arguments`` for the `shell` tool is a serialized JSON object.
+    let tool_call_arguments = serde_json::to_string(&json!({
+        "command": command,
+        "workdir": workdir.map(|w| w.to_string_lossy()),
+        "timeout": timeout_ms
+    }))?;
+    let tool_call = json!({
+        "choices": [
+            {
+                "delta": {
+                    "tool_calls": [
+                        {
+                            "id": call_id,
+                            "function": {
+                                "name": "shell",
+                                "arguments": tool_call_arguments
+                            }
+                        }
+                    ]
+                },
+                "finish_reason": "tool_calls"
+            }
+        ]
+    });
+
+    let sse = format!(
+        "data: {}\n\ndata: DONE\n\n",
+        serde_json::to_string(&tool_call)?
+    );
+    Ok(sse)
+}
+
+pub fn create_final_assistant_message_sse_response(message: &str) -> anyhow::Result<String> {
+    let assistant_message = json!({
+        "choices": [
+            {
+                "delta": {
+                    "content": message
+                },
+                "finish_reason": "stop"
+            }
+        ]
+    });
+
+    let sse = format!(
+        "data: {}\n\ndata: DONE\n\n",
+        serde_json::to_string(&assistant_message)?
+    );
+    Ok(sse)
+}
+
+pub fn create_apply_patch_sse_response(
+    patch_content: &str,
+    call_id: &str,
+) -> anyhow::Result<String> {
+    // Use shell command to call apply_patch with heredoc format
+    let shell_command = format!("apply_patch <<'EOF'\n{patch_content}\nEOF");
+    let tool_call_arguments = serde_json::to_string(&json!({
+        "command": ["bash", "-lc", shell_command]
+    }))?;
+
+    let tool_call = json!({
+        "choices": [
+            {
+                "delta": {
+                    "tool_calls": [
+                        {
+                            "id": call_id,
+                            "function": {
+                                "name": "shell",
+                                "arguments": tool_call_arguments
+                            }
+                        }
+                    ]
+                },
+                "finish_reason": "tool_calls"
+            }
+        ]
+    });
+
+    let sse = format!(
+        "data: {}\n\ndata: DONE\n\n",
+        serde_json::to_string(&tool_call)?
+    );
+    Ok(sse)
+}

codex-rs/app-server/tests/suite/archive_conversation.rs

@@ -0,0 +1,105 @@
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_core::ARCHIVED_SESSIONS_SUBDIR;
+use codex_protocol::mcp_protocol::ArchiveConversationParams;
+use codex_protocol::mcp_protocol::ArchiveConversationResponse;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::NewConversationResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn archive_conversation_moves_rollout_into_archived_directory() {
+    let codex_home = TempDir::new().expect("create temp dir");
+    create_config_toml(codex_home.path()).expect("write config.toml");
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("initialize timeout")
+        .expect("initialize request");
+
+    let new_request_id = mcp
+        .send_new_conversation_request(NewConversationParams {
+            model: Some("mock-model".to_string()),
+            ..Default::default()
+        })
+        .await
+        .expect("send newConversation");
+    let new_response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_request_id)),
+    )
+    .await
+    .expect("newConversation timeout")
+    .expect("newConversation response");
+
+    let NewConversationResponse {
+        conversation_id,
+        rollout_path,
+        ..
+    } = to_response::<NewConversationResponse>(new_response)
+        .expect("deserialize newConversation response");
+
+    assert!(
+        rollout_path.exists(),
+        "expected rollout path {} to exist",
+        rollout_path.display()
+    );
+
+    let archive_request_id = mcp
+        .send_archive_conversation_request(ArchiveConversationParams {
+            conversation_id,
+            rollout_path: rollout_path.clone(),
+        })
+        .await
+        .expect("send archiveConversation");
+    let archive_response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(archive_request_id)),
+    )
+    .await
+    .expect("archiveConversation timeout")
+    .expect("archiveConversation response");
+
+    let _: ArchiveConversationResponse =
+        to_response::<ArchiveConversationResponse>(archive_response)
+            .expect("deserialize archiveConversation response");
+
+    let archived_directory = codex_home.path().join(ARCHIVED_SESSIONS_SUBDIR);
+    let archived_rollout_path =
+        archived_directory.join(rollout_path.file_name().unwrap_or_else(|| {
+            panic!("rollout path {} missing file name", rollout_path.display())
+        }));
+
+    assert!(
+        !rollout_path.exists(),
+        "expected rollout path {} to be moved",
+        rollout_path.display()
+    );
+    assert!(
+        archived_rollout_path.exists(),
+        "expected archived rollout path {} to exist",
+        archived_rollout_path.display()
+    );
+}
+
+fn create_config_toml(codex_home: &Path) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(config_toml, config_contents())
+}
+
+fn config_contents() -> &'static str {
+    r#"model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "read-only"
+"#
+}

codex-rs/app-server/tests/suite/auth.rs

@@ -0,0 +1,223 @@
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_protocol::mcp_protocol::AuthMode;
+use codex_protocol::mcp_protocol::GetAuthStatusParams;
+use codex_protocol::mcp_protocol::GetAuthStatusResponse;
+use codex_protocol::mcp_protocol::LoginApiKeyParams;
+use codex_protocol::mcp_protocol::LoginApiKeyResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+fn create_config_toml_custom_provider(
+    codex_home: &Path,
+    requires_openai_auth: bool,
+) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    let requires_line = if requires_openai_auth {
+        "requires_openai_auth = true\n"
+    } else {
+        ""
+    };
+    let contents = format!(
+        r#"
+model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "danger-full-access"
+
+model_provider = "mock_provider"
+
+[model_providers.mock_provider]
+name = "Mock provider for test"
+base_url = "http://127.0.0.1:0/v1"
+wire_api = "chat"
+request_max_retries = 0
+stream_max_retries = 0
+{requires_line}
+"#
+    );
+    std::fs::write(config_toml, contents)
+}
+
+fn create_config_toml(codex_home: &Path) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        r#"
+model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "danger-full-access"
+"#,
+    )
+}
+
+async fn login_with_api_key_via_request(mcp: &mut McpProcess, api_key: &str) {
+    let request_id = mcp
+        .send_login_api_key_request(LoginApiKeyParams {
+            api_key: api_key.to_string(),
+        })
+        .await
+        .unwrap_or_else(|e| panic!("send loginApiKey: {e}"));
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .unwrap_or_else(|e| panic!("loginApiKey timeout: {e}"))
+    .unwrap_or_else(|e| panic!("loginApiKey response: {e}"));
+    let _: LoginApiKeyResponse =
+        to_response(resp).unwrap_or_else(|e| panic!("deserialize login response: {e}"));
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_auth_status_no_auth() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml(codex_home.path()).unwrap_or_else(|err| panic!("write config.toml: {err}"));
+
+    let mut mcp = McpProcess::new_with_env(codex_home.path(), &[("OPENAI_API_KEY", None)])
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let request_id = mcp
+        .send_get_auth_status_request(GetAuthStatusParams {
+            include_token: Some(true),
+            refresh_token: Some(false),
+        })
+        .await
+        .expect("send getAuthStatus");
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getAuthStatus timeout")
+    .expect("getAuthStatus response");
+    let status: GetAuthStatusResponse = to_response(resp).expect("deserialize status");
+    assert_eq!(status.auth_method, None, "expected no auth method");
+    assert_eq!(status.auth_token, None, "expected no token");
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_auth_status_with_api_key() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml(codex_home.path()).unwrap_or_else(|err| panic!("write config.toml: {err}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    login_with_api_key_via_request(&mut mcp, "sk-test-key").await;
+
+    let request_id = mcp
+        .send_get_auth_status_request(GetAuthStatusParams {
+            include_token: Some(true),
+            refresh_token: Some(false),
+        })
+        .await
+        .expect("send getAuthStatus");
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getAuthStatus timeout")
+    .expect("getAuthStatus response");
+    let status: GetAuthStatusResponse = to_response(resp).expect("deserialize status");
+    assert_eq!(status.auth_method, Some(AuthMode::ApiKey));
+    assert_eq!(status.auth_token, Some("sk-test-key".to_string()));
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_auth_status_with_api_key_when_auth_not_required() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml_custom_provider(codex_home.path(), false)
+        .unwrap_or_else(|err| panic!("write config.toml: {err}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    login_with_api_key_via_request(&mut mcp, "sk-test-key").await;
+
+    let request_id = mcp
+        .send_get_auth_status_request(GetAuthStatusParams {
+            include_token: Some(true),
+            refresh_token: Some(false),
+        })
+        .await
+        .expect("send getAuthStatus");
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getAuthStatus timeout")
+    .expect("getAuthStatus response");
+    let status: GetAuthStatusResponse = to_response(resp).expect("deserialize status");
+    assert_eq!(status.auth_method, None, "expected no auth method");
+    assert_eq!(status.auth_token, None, "expected no token");
+    assert_eq!(
+        status.requires_openai_auth,
+        Some(false),
+        "requires_openai_auth should be false",
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_auth_status_with_api_key_no_include_token() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml(codex_home.path()).unwrap_or_else(|err| panic!("write config.toml: {err}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    login_with_api_key_via_request(&mut mcp, "sk-test-key").await;
+
+    // Build params via struct so None field is omitted in wire JSON.
+    let params = GetAuthStatusParams {
+        include_token: None,
+        refresh_token: Some(false),
+    };
+    let request_id = mcp
+        .send_get_auth_status_request(params)
+        .await
+        .expect("send getAuthStatus");
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getAuthStatus timeout")
+    .expect("getAuthStatus response");
+    let status: GetAuthStatusResponse = to_response(resp).expect("deserialize status");
+    assert_eq!(status.auth_method, Some(AuthMode::ApiKey));
+    assert!(status.auth_token.is_none(), "token must be omitted");
+}

codex-rs/app-server/tests/suite/codex_message_processor_flow.rs

@@ -0,0 +1,372 @@
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::create_final_assistant_message_sse_response;
+use app_test_support::create_mock_chat_completions_server;
+use app_test_support::create_shell_sse_response;
+use app_test_support::to_response;
+use codex_core::protocol::AskForApproval;
+use codex_core::protocol::SandboxPolicy;
+use codex_core::protocol_config_types::ReasoningEffort;
+use codex_core::protocol_config_types::ReasoningSummary;
+use codex_core::spawn::CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR;
+use codex_protocol::mcp_protocol::AddConversationListenerParams;
+use codex_protocol::mcp_protocol::AddConversationSubscriptionResponse;
+use codex_protocol::mcp_protocol::EXEC_COMMAND_APPROVAL_METHOD;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::NewConversationResponse;
+use codex_protocol::mcp_protocol::RemoveConversationListenerParams;
+use codex_protocol::mcp_protocol::RemoveConversationSubscriptionResponse;
+use codex_protocol::mcp_protocol::SendUserMessageParams;
+use codex_protocol::mcp_protocol::SendUserMessageResponse;
+use codex_protocol::mcp_protocol::SendUserTurnParams;
+use codex_protocol::mcp_protocol::SendUserTurnResponse;
+use mcp_types::JSONRPCNotification;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use std::env;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn test_codex_jsonrpc_conversation_flow() {
+    if env::var(CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR).is_ok() {
+        println!(
+            "Skipping test because it cannot execute when network is disabled in a Codex sandbox."
+        );
+        return;
+    }
+
+    let tmp = TempDir::new().expect("tmp dir");
+    // Temporary Codex home with config pointing at the mock server.
+    let codex_home = tmp.path().join("codex_home");
+    std::fs::create_dir(&codex_home).expect("create codex home dir");
+    let working_directory = tmp.path().join("workdir");
+    std::fs::create_dir(&working_directory).expect("create working directory");
+
+    // Create a mock model server that immediately ends each turn.
+    // Two turns are expected: initial session configure + one user message.
+    let responses = vec![
+        create_shell_sse_response(
+            vec!["ls".to_string()],
+            Some(&working_directory),
+            Some(5000),
+            "call1234",
+        )
+        .expect("create shell sse response"),
+        create_final_assistant_message_sse_response("Enjoy your new git repo!")
+            .expect("create final assistant message"),
+    ];
+    let server = create_mock_chat_completions_server(responses).await;
+    create_config_toml(&codex_home, &server.uri()).expect("write config");
+
+    // Start MCP server and initialize.
+    let mut mcp = McpProcess::new(&codex_home).await.expect("spawn mcp");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init error");
+
+    // 1) newConversation
+    let new_conv_id = mcp
+        .send_new_conversation_request(NewConversationParams {
+            cwd: Some(working_directory.to_string_lossy().into_owned()),
+            ..Default::default()
+        })
+        .await
+        .expect("send newConversation");
+    let new_conv_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_conv_id)),
+    )
+    .await
+    .expect("newConversation timeout")
+    .expect("newConversation resp");
+    let new_conv_resp = to_response::<NewConversationResponse>(new_conv_resp)
+        .expect("deserialize newConversation response");
+    let NewConversationResponse {
+        conversation_id,
+        model,
+        reasoning_effort: _,
+        rollout_path: _,
+    } = new_conv_resp;
+    assert_eq!(model, "mock-model");
+
+    // 2) addConversationListener
+    let add_listener_id = mcp
+        .send_add_conversation_listener_request(AddConversationListenerParams { conversation_id })
+        .await
+        .expect("send addConversationListener");
+    let add_listener_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(add_listener_id)),
+    )
+    .await
+    .expect("addConversationListener timeout")
+    .expect("addConversationListener resp");
+    let AddConversationSubscriptionResponse { subscription_id } =
+        to_response::<AddConversationSubscriptionResponse>(add_listener_resp)
+            .expect("deserialize addConversationListener response");
+
+    // 3) sendUserMessage (should trigger notifications; we only validate an OK response)
+    let send_user_id = mcp
+        .send_send_user_message_request(SendUserMessageParams {
+            conversation_id,
+            items: vec![codex_protocol::mcp_protocol::InputItem::Text {
+                text: "text".to_string(),
+            }],
+        })
+        .await
+        .expect("send sendUserMessage");
+    let send_user_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(send_user_id)),
+    )
+    .await
+    .expect("sendUserMessage timeout")
+    .expect("sendUserMessage resp");
+    let SendUserMessageResponse {} = to_response::<SendUserMessageResponse>(send_user_resp)
+        .expect("deserialize sendUserMessage response");
+
+    // Verify the task_finished notification is received.
+    // Note this also ensures that the final request to the server was made.
+    let task_finished_notification: JSONRPCNotification = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("codex/event/task_complete"),
+    )
+    .await
+    .expect("task_finished_notification timeout")
+    .expect("task_finished_notification resp");
+    let serde_json::Value::Object(map) = task_finished_notification
+        .params
+        .expect("notification should have params")
+    else {
+        panic!("task_finished_notification should have params");
+    };
+    assert_eq!(
+        map.get("conversationId")
+            .expect("should have conversationId"),
+        &serde_json::Value::String(conversation_id.to_string())
+    );
+
+    // 4) removeConversationListener
+    let remove_listener_id = mcp
+        .send_remove_conversation_listener_request(RemoveConversationListenerParams {
+            subscription_id,
+        })
+        .await
+        .expect("send removeConversationListener");
+    let remove_listener_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(remove_listener_id)),
+    )
+    .await
+    .expect("removeConversationListener timeout")
+    .expect("removeConversationListener resp");
+    let RemoveConversationSubscriptionResponse {} =
+        to_response(remove_listener_resp).expect("deserialize removeConversationListener response");
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn test_send_user_turn_changes_approval_policy_behavior() {
+    if env::var(CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR).is_ok() {
+        println!(
+            "Skipping test because it cannot execute when network is disabled in a Codex sandbox."
+        );
+        return;
+    }
+
+    let tmp = TempDir::new().expect("tmp dir");
+    let codex_home = tmp.path().join("codex_home");
+    std::fs::create_dir(&codex_home).expect("create codex home dir");
+    let working_directory = tmp.path().join("workdir");
+    std::fs::create_dir(&working_directory).expect("create working directory");
+
+    // Mock server will request a python shell call for the first and second turn, then finish.
+    let responses = vec![
+        create_shell_sse_response(
+            vec![
+                "python3".to_string(),
+                "-c".to_string(),
+                "print(42)".to_string(),
+            ],
+            Some(&working_directory),
+            Some(5000),
+            "call1",
+        )
+        .expect("create first shell sse response"),
+        create_final_assistant_message_sse_response("done 1")
+            .expect("create final assistant message 1"),
+        create_shell_sse_response(
+            vec![
+                "python3".to_string(),
+                "-c".to_string(),
+                "print(42)".to_string(),
+            ],
+            Some(&working_directory),
+            Some(5000),
+            "call2",
+        )
+        .expect("create second shell sse response"),
+        create_final_assistant_message_sse_response("done 2")
+            .expect("create final assistant message 2"),
+    ];
+    let server = create_mock_chat_completions_server(responses).await;
+    create_config_toml(&codex_home, &server.uri()).expect("write config");
+
+    // Start MCP server and initialize.
+    let mut mcp = McpProcess::new(&codex_home).await.expect("spawn mcp");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init error");
+
+    // 1) Start conversation with approval_policy=untrusted
+    let new_conv_id = mcp
+        .send_new_conversation_request(NewConversationParams {
+            cwd: Some(working_directory.to_string_lossy().into_owned()),
+            ..Default::default()
+        })
+        .await
+        .expect("send newConversation");
+    let new_conv_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_conv_id)),
+    )
+    .await
+    .expect("newConversation timeout")
+    .expect("newConversation resp");
+    let NewConversationResponse {
+        conversation_id, ..
+    } = to_response::<NewConversationResponse>(new_conv_resp)
+        .expect("deserialize newConversation response");
+
+    // 2) addConversationListener
+    let add_listener_id = mcp
+        .send_add_conversation_listener_request(AddConversationListenerParams { conversation_id })
+        .await
+        .expect("send addConversationListener");
+    let _: AddConversationSubscriptionResponse =
+        to_response::<AddConversationSubscriptionResponse>(
+            timeout(
+                DEFAULT_READ_TIMEOUT,
+                mcp.read_stream_until_response_message(RequestId::Integer(add_listener_id)),
+            )
+            .await
+            .expect("addConversationListener timeout")
+            .expect("addConversationListener resp"),
+        )
+        .expect("deserialize addConversationListener response");
+
+    // 3) sendUserMessage triggers a shell call; approval policy is Untrusted so we should get an elicitation
+    let send_user_id = mcp
+        .send_send_user_message_request(SendUserMessageParams {
+            conversation_id,
+            items: vec![codex_protocol::mcp_protocol::InputItem::Text {
+                text: "run python".to_string(),
+            }],
+        })
+        .await
+        .expect("send sendUserMessage");
+    let _send_user_resp: SendUserMessageResponse = to_response::<SendUserMessageResponse>(
+        timeout(
+            DEFAULT_READ_TIMEOUT,
+            mcp.read_stream_until_response_message(RequestId::Integer(send_user_id)),
+        )
+        .await
+        .expect("sendUserMessage timeout")
+        .expect("sendUserMessage resp"),
+    )
+    .expect("deserialize sendUserMessage response");
+
+    // Expect an ExecCommandApproval request (elicitation)
+    let request = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_request_message(),
+    )
+    .await
+    .expect("waiting for exec approval request timeout")
+    .expect("exec approval request");
+    assert_eq!(request.method, EXEC_COMMAND_APPROVAL_METHOD);
+
+    // Approve so the first turn can complete
+    mcp.send_response(
+        request.id,
+        serde_json::json!({ "decision": codex_core::protocol::ReviewDecision::Approved }),
+    )
+    .await
+    .expect("send approval response");
+
+    // Wait for first TaskComplete
+    let _ = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("codex/event/task_complete"),
+    )
+    .await
+    .expect("task_complete 1 timeout")
+    .expect("task_complete 1 notification");
+
+    // 4) sendUserTurn with approval_policy=never should run without elicitation
+    let send_turn_id = mcp
+        .send_send_user_turn_request(SendUserTurnParams {
+            conversation_id,
+            items: vec![codex_protocol::mcp_protocol::InputItem::Text {
+                text: "run python again".to_string(),
+            }],
+            cwd: working_directory.clone(),
+            approval_policy: AskForApproval::Never,
+            sandbox_policy: SandboxPolicy::new_read_only_policy(),
+            model: "mock-model".to_string(),
+            effort: Some(ReasoningEffort::Medium),
+            summary: ReasoningSummary::Auto,
+        })
+        .await
+        .expect("send sendUserTurn");
+    // Acknowledge sendUserTurn
+    let _send_turn_resp: SendUserTurnResponse = to_response::<SendUserTurnResponse>(
+        timeout(
+            DEFAULT_READ_TIMEOUT,
+            mcp.read_stream_until_response_message(RequestId::Integer(send_turn_id)),
+        )
+        .await
+        .expect("sendUserTurn timeout")
+        .expect("sendUserTurn resp"),
+    )
+    .expect("deserialize sendUserTurn response");
+
+    // Ensure we do NOT receive an ExecCommandApproval request before the task completes.
+    // If any Request is seen while waiting for task_complete, the helper will error and the test fails.
+    let _ = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("codex/event/task_complete"),
+    )
+    .await
+    .expect("task_complete 2 timeout")
+    .expect("task_complete 2 notification");
+}
+
+// Helper: minimal config.toml pointing at mock provider.
+fn create_config_toml(codex_home: &Path, server_uri: &str) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        format!(
+            r#"
+model = "mock-model"
+approval_policy = "untrusted"
+
+model_provider = "mock_provider"
+
+[model_providers.mock_provider]
+name = "Mock provider for test"
+base_url = "{server_uri}/v1"
+wire_api = "chat"
+request_max_retries = 0
+stream_max_retries = 0
+"#
+        ),
+    )
+}

codex-rs/app-server/tests/suite/config.rs

@@ -0,0 +1,163 @@
+use std::collections::HashMap;
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_core::protocol::AskForApproval;
+use codex_protocol::config_types::ReasoningEffort;
+use codex_protocol::config_types::ReasoningSummary;
+use codex_protocol::config_types::SandboxMode;
+use codex_protocol::config_types::Verbosity;
+use codex_protocol::mcp_protocol::GetUserSavedConfigResponse;
+use codex_protocol::mcp_protocol::Profile;
+use codex_protocol::mcp_protocol::SandboxSettings;
+use codex_protocol::mcp_protocol::Tools;
+use codex_protocol::mcp_protocol::UserSavedConfig;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+fn create_config_toml(codex_home: &Path) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        r#"
+model = "gpt-5-codex"
+approval_policy = "on-request"
+sandbox_mode = "workspace-write"
+model_reasoning_summary = "detailed"
+model_reasoning_effort = "high"
+model_verbosity = "medium"
+profile = "test"
+
+[sandbox_workspace_write]
+writable_roots = ["/tmp"]
+network_access = true
+exclude_tmpdir_env_var = true
+exclude_slash_tmp = true
+
+[tools]
+web_search = false
+view_image = true
+
+[profiles.test]
+model = "gpt-4o"
+approval_policy = "on-request"
+model_reasoning_effort = "high"
+model_reasoning_summary = "detailed"
+model_verbosity = "medium"
+model_provider = "openai"
+chatgpt_base_url = "https://api.chatgpt.com"
+"#,
+    )
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn get_config_toml_parses_all_fields() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml(codex_home.path()).expect("write config.toml");
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let request_id = mcp
+        .send_get_user_saved_config_request()
+        .await
+        .expect("send getUserSavedConfig");
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getUserSavedConfig timeout")
+    .expect("getUserSavedConfig response");
+
+    let config: GetUserSavedConfigResponse = to_response(resp).expect("deserialize config");
+    let expected = GetUserSavedConfigResponse {
+        config: UserSavedConfig {
+            approval_policy: Some(AskForApproval::OnRequest),
+            sandbox_mode: Some(SandboxMode::WorkspaceWrite),
+            sandbox_settings: Some(SandboxSettings {
+                writable_roots: vec!["/tmp".into()],
+                network_access: Some(true),
+                exclude_tmpdir_env_var: Some(true),
+                exclude_slash_tmp: Some(true),
+            }),
+            model: Some("gpt-5-codex".into()),
+            model_reasoning_effort: Some(ReasoningEffort::High),
+            model_reasoning_summary: Some(ReasoningSummary::Detailed),
+            model_verbosity: Some(Verbosity::Medium),
+            tools: Some(Tools {
+                web_search: Some(false),
+                view_image: Some(true),
+            }),
+            profile: Some("test".to_string()),
+            profiles: HashMap::from([(
+                "test".into(),
+                Profile {
+                    model: Some("gpt-4o".into()),
+                    approval_policy: Some(AskForApproval::OnRequest),
+                    model_reasoning_effort: Some(ReasoningEffort::High),
+                    model_reasoning_summary: Some(ReasoningSummary::Detailed),
+                    model_verbosity: Some(Verbosity::Medium),
+                    model_provider: Some("openai".into()),
+                    chatgpt_base_url: Some("https://api.chatgpt.com".into()),
+                },
+            )]),
+        },
+    };
+
+    assert_eq!(config, expected);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_config_toml_empty() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let request_id = mcp
+        .send_get_user_saved_config_request()
+        .await
+        .expect("send getUserSavedConfig");
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getUserSavedConfig timeout")
+    .expect("getUserSavedConfig response");
+
+    let config: GetUserSavedConfigResponse = to_response(resp).expect("deserialize config");
+    let expected = GetUserSavedConfigResponse {
+        config: UserSavedConfig {
+            approval_policy: None,
+            sandbox_mode: None,
+            sandbox_settings: None,
+            model: None,
+            model_reasoning_effort: None,
+            model_reasoning_summary: None,
+            model_verbosity: None,
+            tools: None,
+            profile: None,
+            profiles: HashMap::new(),
+        },
+    };
+
+    assert_eq!(config, expected);
+}

codex-rs/app-server/tests/suite/create_conversation.rs

@@ -0,0 +1,157 @@
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::create_final_assistant_message_sse_response;
+use app_test_support::create_mock_chat_completions_server;
+use app_test_support::to_response;
+use codex_protocol::mcp_protocol::AddConversationListenerParams;
+use codex_protocol::mcp_protocol::AddConversationSubscriptionResponse;
+use codex_protocol::mcp_protocol::InputItem;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::NewConversationResponse;
+use codex_protocol::mcp_protocol::SendUserMessageParams;
+use codex_protocol::mcp_protocol::SendUserMessageResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_conversation_create_and_send_message_ok() {
+    // Mock server – we won't strictly rely on it, but provide one to satisfy any model wiring.
+    let responses = vec![
+        create_final_assistant_message_sse_response("Done").expect("build mock assistant message"),
+    ];
+    let server = create_mock_chat_completions_server(responses).await;
+
+    // Temporary Codex home with config pointing at the mock server.
+    let codex_home = TempDir::new().expect("create temp dir");
+    create_config_toml(codex_home.path(), &server.uri()).expect("write config.toml");
+
+    // Start MCP server process and initialize.
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    // Create a conversation via the new JSON-RPC API.
+    let new_conv_id = mcp
+        .send_new_conversation_request(NewConversationParams {
+            model: Some("o3".to_string()),
+            ..Default::default()
+        })
+        .await
+        .expect("send newConversation");
+    let new_conv_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_conv_id)),
+    )
+    .await
+    .expect("newConversation timeout")
+    .expect("newConversation resp");
+    let NewConversationResponse {
+        conversation_id,
+        model,
+        reasoning_effort: _,
+        rollout_path: _,
+    } = to_response::<NewConversationResponse>(new_conv_resp)
+        .expect("deserialize newConversation response");
+    assert_eq!(model, "o3");
+
+    // Add a listener so we receive notifications for this conversation (not strictly required for this test).
+    let add_listener_id = mcp
+        .send_add_conversation_listener_request(AddConversationListenerParams { conversation_id })
+        .await
+        .expect("send addConversationListener");
+    let _sub: AddConversationSubscriptionResponse =
+        to_response::<AddConversationSubscriptionResponse>(
+            timeout(
+                DEFAULT_READ_TIMEOUT,
+                mcp.read_stream_until_response_message(RequestId::Integer(add_listener_id)),
+            )
+            .await
+            .expect("addConversationListener timeout")
+            .expect("addConversationListener resp"),
+        )
+        .expect("deserialize addConversationListener response");
+
+    // Now send a user message via the wire API and expect an OK (empty object) result.
+    let send_id = mcp
+        .send_send_user_message_request(SendUserMessageParams {
+            conversation_id,
+            items: vec![InputItem::Text {
+                text: "Hello".to_string(),
+            }],
+        })
+        .await
+        .expect("send sendUserMessage");
+    let send_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(send_id)),
+    )
+    .await
+    .expect("sendUserMessage timeout")
+    .expect("sendUserMessage resp");
+    let _ok: SendUserMessageResponse = to_response::<SendUserMessageResponse>(send_resp)
+        .expect("deserialize sendUserMessage response");
+
+    // avoid race condition by waiting for the mock server to receive the chat.completions request
+    let deadline = std::time::Instant::now() + DEFAULT_READ_TIMEOUT;
+    loop {
+        let requests = server.received_requests().await.unwrap_or_default();
+        if !requests.is_empty() {
+            break;
+        }
+        if std::time::Instant::now() >= deadline {
+            panic!("mock server did not receive the chat.completions request in time");
+        }
+        tokio::time::sleep(std::time::Duration::from_millis(10)).await;
+    }
+
+    // Verify the outbound request body matches expectations for Chat Completions.
+    let request = &server.received_requests().await.unwrap()[0];
+    let body = request
+        .body_json::<serde_json::Value>()
+        .expect("parse request body as JSON");
+    assert_eq!(body["model"], json!("o3"));
+    assert!(body["stream"].as_bool().unwrap_or(false));
+    let messages = body["messages"]
+        .as_array()
+        .expect("messages should be array");
+    let last = messages.last().expect("at least one message");
+    assert_eq!(last["role"], json!("user"));
+    assert_eq!(last["content"], json!("Hello"));
+
+    drop(server);
+}
+
+// Helper to create a config.toml pointing at the mock model server.
+fn create_config_toml(codex_home: &Path, server_uri: &str) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        format!(
+            r#"
+model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "danger-full-access"
+
+model_provider = "mock_provider"
+
+[model_providers.mock_provider]
+name = "Mock provider for test"
+base_url = "{server_uri}/v1"
+wire_api = "chat"
+request_max_retries = 0
+stream_max_retries = 0
+"#
+        ),
+    )
+}

codex-rs/app-server/tests/suite/fuzzy_file_search.rs

@@ -0,0 +1,104 @@
+use app_test_support::McpProcess;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_fuzzy_file_search_sorts_and_includes_indices() {
+    // Prepare a temporary Codex home and a separate root with test files.
+    let codex_home = TempDir::new().expect("create temp codex home");
+    let root = TempDir::new().expect("create temp search root");
+
+    // Create files designed to have deterministic ordering for query "abc".
+    std::fs::write(root.path().join("abc"), "x").expect("write file abc");
+    std::fs::write(root.path().join("abcde"), "x").expect("write file abcx");
+    std::fs::write(root.path().join("abexy"), "x").expect("write file abcx");
+    std::fs::write(root.path().join("zzz.txt"), "x").expect("write file zzz");
+
+    // Start MCP server and initialize.
+    let mut mcp = McpProcess::new(codex_home.path()).await.expect("spawn mcp");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let root_path = root.path().to_string_lossy().to_string();
+    // Send fuzzyFileSearch request.
+    let request_id = mcp
+        .send_fuzzy_file_search_request("abe", vec![root_path.clone()], None)
+        .await
+        .expect("send fuzzyFileSearch");
+
+    // Read response and verify shape and ordering.
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("fuzzyFileSearch timeout")
+    .expect("fuzzyFileSearch resp");
+
+    let value = resp.result;
+    assert_eq!(
+        value,
+        json!({
+            "files": [
+                { "root": root_path.clone(), "path": "abexy", "score": 88, "indices": [0, 1, 2] },
+                { "root": root_path.clone(), "path": "abcde", "score": 74, "indices": [0, 1, 4] },
+            ]
+        })
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_fuzzy_file_search_accepts_cancellation_token() {
+    let codex_home = TempDir::new().expect("create temp codex home");
+    let root = TempDir::new().expect("create temp search root");
+
+    std::fs::write(root.path().join("alpha.txt"), "contents").expect("write alpha");
+
+    let mut mcp = McpProcess::new(codex_home.path()).await.expect("spawn mcp");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let root_path = root.path().to_string_lossy().to_string();
+    let request_id = mcp
+        .send_fuzzy_file_search_request("alp", vec![root_path.clone()], None)
+        .await
+        .expect("send fuzzyFileSearch");
+
+    let request_id_2 = mcp
+        .send_fuzzy_file_search_request(
+            "alp",
+            vec![root_path.clone()],
+            Some(request_id.to_string()),
+        )
+        .await
+        .expect("send fuzzyFileSearch");
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id_2)),
+    )
+    .await
+    .expect("fuzzyFileSearch timeout")
+    .expect("fuzzyFileSearch resp");
+
+    let files = resp
+        .result
+        .get("files")
+        .and_then(|value| value.as_array())
+        .cloned()
+        .expect("files array");
+
+    assert_eq!(files.len(), 1);
+    assert_eq!(files[0]["root"], root_path);
+    assert_eq!(files[0]["path"], "alpha.txt");
+}

codex-rs/app-server/tests/suite/interrupt.rs

@@ -0,0 +1,159 @@
+#![cfg(unix)]
+// Support code lives in the `app_test_support` crate under tests/common.
+
+use std::path::Path;
+
+use codex_core::protocol::TurnAbortReason;
+use codex_protocol::mcp_protocol::AddConversationListenerParams;
+use codex_protocol::mcp_protocol::InterruptConversationParams;
+use codex_protocol::mcp_protocol::InterruptConversationResponse;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::NewConversationResponse;
+use codex_protocol::mcp_protocol::SendUserMessageParams;
+use codex_protocol::mcp_protocol::SendUserMessageResponse;
+use core_test_support::skip_if_no_network;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+use app_test_support::McpProcess;
+use app_test_support::create_mock_chat_completions_server;
+use app_test_support::create_shell_sse_response;
+use app_test_support::to_response;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_shell_command_interruption() {
+    skip_if_no_network!();
+
+    if let Err(err) = shell_command_interruption().await {
+        panic!("failure: {err}");
+    }
+}
+
+async fn shell_command_interruption() -> anyhow::Result<()> {
+    // Use a cross-platform blocking command. On Windows plain `sleep` is not guaranteed to exist
+    // (MSYS/GNU coreutils may be absent) and the failure causes the tool call to finish immediately,
+    // which triggers a second model request before the test sends the explicit follow-up. That
+    // prematurely consumes the second mocked SSE response and leads to a third POST (panic: no response for 2).
+    // Powershell Start-Sleep is always available on Windows runners. On Unix we keep using `sleep`.
+    #[cfg(target_os = "windows")]
+    let shell_command = vec![
+        "powershell".to_string(),
+        "-Command".to_string(),
+        "Start-Sleep -Seconds 10".to_string(),
+    ];
+    #[cfg(not(target_os = "windows"))]
+    let shell_command = vec!["sleep".to_string(), "10".to_string()];
+
+    let tmp = TempDir::new()?;
+    // Temporary Codex home with config pointing at the mock server.
+    let codex_home = tmp.path().join("codex_home");
+    std::fs::create_dir(&codex_home)?;
+    let working_directory = tmp.path().join("workdir");
+    std::fs::create_dir(&working_directory)?;
+
+    // Create mock server with a single SSE response: the long sleep command
+    let server = create_mock_chat_completions_server(vec![create_shell_sse_response(
+        shell_command.clone(),
+        Some(&working_directory),
+        Some(10_000), // 10 seconds timeout in ms
+        "call_sleep",
+    )?])
+    .await;
+    create_config_toml(&codex_home, server.uri())?;
+
+    // Start MCP server and initialize.
+    let mut mcp = McpProcess::new(&codex_home).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    // 1) newConversation
+    let new_conv_id = mcp
+        .send_new_conversation_request(NewConversationParams {
+            cwd: Some(working_directory.to_string_lossy().into_owned()),
+            ..Default::default()
+        })
+        .await?;
+    let new_conv_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_conv_id)),
+    )
+    .await??;
+    let new_conv_resp = to_response::<NewConversationResponse>(new_conv_resp)?;
+    let NewConversationResponse {
+        conversation_id, ..
+    } = new_conv_resp;
+
+    // 2) addConversationListener
+    let add_listener_id = mcp
+        .send_add_conversation_listener_request(AddConversationListenerParams { conversation_id })
+        .await?;
+    let _add_listener_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(add_listener_id)),
+    )
+    .await??;
+
+    // 3) sendUserMessage (should trigger notifications; we only validate an OK response)
+    let send_user_id = mcp
+        .send_send_user_message_request(SendUserMessageParams {
+            conversation_id,
+            items: vec![codex_protocol::mcp_protocol::InputItem::Text {
+                text: "run first sleep command".to_string(),
+            }],
+        })
+        .await?;
+    let send_user_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(send_user_id)),
+    )
+    .await??;
+    let SendUserMessageResponse {} = to_response::<SendUserMessageResponse>(send_user_resp)?;
+
+    // Give the command a moment to start
+    tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+
+    // 4) send interrupt request
+    let interrupt_id = mcp
+        .send_interrupt_conversation_request(InterruptConversationParams { conversation_id })
+        .await?;
+    let interrupt_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(interrupt_id)),
+    )
+    .await??;
+    let InterruptConversationResponse { abort_reason } =
+        to_response::<InterruptConversationResponse>(interrupt_resp)?;
+    assert_eq!(TurnAbortReason::Interrupted, abort_reason);
+
+    Ok(())
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+fn create_config_toml(codex_home: &Path, server_uri: String) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        format!(
+            r#"
+model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "danger-full-access"
+
+model_provider = "mock_provider"
+
+[model_providers.mock_provider]
+name = "Mock provider for test"
+base_url = "{server_uri}/v1"
+wire_api = "chat"
+request_max_retries = 0
+stream_max_retries = 0
+"#
+        ),
+    )
+}

codex-rs/app-server/tests/suite/list_resume.rs

@@ -0,0 +1,210 @@
+use std::fs;
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_protocol::mcp_protocol::ListConversationsParams;
+use codex_protocol::mcp_protocol::ListConversationsResponse;
+use codex_protocol::mcp_protocol::NewConversationParams; // reused for overrides shape
+use codex_protocol::mcp_protocol::ResumeConversationParams;
+use codex_protocol::mcp_protocol::ResumeConversationResponse;
+use codex_protocol::mcp_protocol::ServerNotification;
+use codex_protocol::mcp_protocol::SessionConfiguredNotification;
+use mcp_types::JSONRPCNotification;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::time::timeout;
+use uuid::Uuid;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_list_and_resume_conversations() {
+    // Prepare a temporary CODEX_HOME with a few fake rollout files.
+    let codex_home = TempDir::new().expect("create temp dir");
+    create_fake_rollout(
+        codex_home.path(),
+        "2025-01-02T12-00-00",
+        "2025-01-02T12:00:00Z",
+        "Hello A",
+    );
+    create_fake_rollout(
+        codex_home.path(),
+        "2025-01-01T13-00-00",
+        "2025-01-01T13:00:00Z",
+        "Hello B",
+    );
+    create_fake_rollout(
+        codex_home.path(),
+        "2025-01-01T12-00-00",
+        "2025-01-01T12:00:00Z",
+        "Hello C",
+    );
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    // Request first page with size 2
+    let req_id = mcp
+        .send_list_conversations_request(ListConversationsParams {
+            page_size: Some(2),
+            cursor: None,
+        })
+        .await
+        .expect("send listConversations");
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(req_id)),
+    )
+    .await
+    .expect("listConversations timeout")
+    .expect("listConversations resp");
+    let ListConversationsResponse { items, next_cursor } =
+        to_response::<ListConversationsResponse>(resp).expect("deserialize response");
+
+    assert_eq!(items.len(), 2);
+    // Newest first; preview text should match
+    assert_eq!(items[0].preview, "Hello A");
+    assert_eq!(items[1].preview, "Hello B");
+    assert!(items[0].path.is_absolute());
+    assert!(next_cursor.is_some());
+
+    // Request the next page using the cursor
+    let req_id2 = mcp
+        .send_list_conversations_request(ListConversationsParams {
+            page_size: Some(2),
+            cursor: next_cursor,
+        })
+        .await
+        .expect("send listConversations page 2");
+    let resp2: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(req_id2)),
+    )
+    .await
+    .expect("listConversations page 2 timeout")
+    .expect("listConversations page 2 resp");
+    let ListConversationsResponse {
+        items: items2,
+        next_cursor: next2,
+        ..
+    } = to_response::<ListConversationsResponse>(resp2).expect("deserialize response");
+    assert_eq!(items2.len(), 1);
+    assert_eq!(items2[0].preview, "Hello C");
+    assert!(next2.is_some());
+
+    // Now resume one of the sessions and expect a SessionConfigured notification and response.
+    let resume_req_id = mcp
+        .send_resume_conversation_request(ResumeConversationParams {
+            path: items[0].path.clone(),
+            overrides: Some(NewConversationParams {
+                model: Some("o3".to_string()),
+                ..Default::default()
+            }),
+        })
+        .await
+        .expect("send resumeConversation");
+
+    // Expect a codex/event notification with msg.type == sessionConfigured
+    let notification: JSONRPCNotification = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("sessionConfigured"),
+    )
+    .await
+    .expect("sessionConfigured notification timeout")
+    .expect("sessionConfigured notification");
+    let session_configured: ServerNotification = notification
+        .try_into()
+        .expect("deserialize sessionConfigured notification");
+    // Basic shape assertion: ensure event type is sessionConfigured
+    let ServerNotification::SessionConfigured(SessionConfiguredNotification {
+        model,
+        rollout_path,
+        ..
+    }) = session_configured
+    else {
+        unreachable!("expected sessionConfigured notification");
+    };
+    assert_eq!(model, "o3");
+    assert_eq!(items[0].path.clone(), rollout_path);
+
+    // Then the response for resumeConversation
+    let resume_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(resume_req_id)),
+    )
+    .await
+    .expect("resumeConversation timeout")
+    .expect("resumeConversation resp");
+    let ResumeConversationResponse {
+        conversation_id, ..
+    } = to_response::<ResumeConversationResponse>(resume_resp)
+        .expect("deserialize resumeConversation response");
+    // conversation id should be a valid UUID
+    assert!(!conversation_id.to_string().is_empty());
+}
+
+fn create_fake_rollout(codex_home: &Path, filename_ts: &str, meta_rfc3339: &str, preview: &str) {
+    let uuid = Uuid::new_v4();
+    // sessions/YYYY/MM/DD/ derived from filename_ts (YYYY-MM-DDThh-mm-ss)
+    let year = &filename_ts[0..4];
+    let month = &filename_ts[5..7];
+    let day = &filename_ts[8..10];
+    let dir = codex_home.join("sessions").join(year).join(month).join(day);
+    fs::create_dir_all(&dir).unwrap_or_else(|e| panic!("create sessions dir: {e}"));
+
+    let file_path = dir.join(format!("rollout-{filename_ts}-{uuid}.jsonl"));
+    let mut lines = Vec::new();
+    // Meta line with timestamp (flattened meta in payload for new schema)
+    lines.push(
+        json!({
+            "timestamp": meta_rfc3339,
+            "type": "session_meta",
+            "payload": {
+                "id": uuid,
+                "timestamp": meta_rfc3339,
+                "cwd": "/",
+                "originator": "codex",
+                "cli_version": "0.0.0",
+                "instructions": null
+            }
+        })
+        .to_string(),
+    );
+    // Minimal user message entry as a persisted response item (with envelope timestamp)
+    lines.push(
+        json!({
+            "timestamp": meta_rfc3339,
+            "type":"response_item",
+            "payload": {
+                "type":"message",
+                "role":"user",
+                "content":[{"type":"input_text","text": preview}]
+            }
+        })
+        .to_string(),
+    );
+    // Add a matching user message event line to satisfy filters
+    lines.push(
+        json!({
+            "timestamp": meta_rfc3339,
+            "type":"event_msg",
+            "payload": {
+                "type":"user_message",
+                "message": preview,
+                "kind": "plain"
+            }
+        })
+        .to_string(),
+    );
+    fs::write(file_path, lines.join("\n") + "\n")
+        .unwrap_or_else(|e| panic!("write rollout file: {e}"));
+}

codex-rs/app-server/tests/suite/login.rs

@@ -0,0 +1,146 @@
+use std::path::Path;
+use std::time::Duration;
+
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_login::login_with_api_key;
+use codex_protocol::mcp_protocol::CancelLoginChatGptParams;
+use codex_protocol::mcp_protocol::CancelLoginChatGptResponse;
+use codex_protocol::mcp_protocol::GetAuthStatusParams;
+use codex_protocol::mcp_protocol::GetAuthStatusResponse;
+use codex_protocol::mcp_protocol::LoginChatGptResponse;
+use codex_protocol::mcp_protocol::LogoutChatGptResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+// Helper to create a config.toml; mirrors create_conversation.rs
+fn create_config_toml(codex_home: &Path) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        r#"
+model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "danger-full-access"
+
+model_provider = "mock_provider"
+
+[model_providers.mock_provider]
+name = "Mock provider for test"
+base_url = "http://127.0.0.1:0/v1"
+wire_api = "chat"
+request_max_retries = 0
+stream_max_retries = 0
+"#,
+    )
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn logout_chatgpt_removes_auth() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml(codex_home.path()).expect("write config.toml");
+    login_with_api_key(codex_home.path(), "sk-test-key").expect("seed api key");
+    assert!(codex_home.path().join("auth.json").exists());
+
+    let mut mcp = McpProcess::new_with_env(codex_home.path(), &[("OPENAI_API_KEY", None)])
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let id = mcp
+        .send_logout_chat_gpt_request()
+        .await
+        .expect("send logoutChatGpt");
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(id)),
+    )
+    .await
+    .expect("logoutChatGpt timeout")
+    .expect("logoutChatGpt response");
+    let _ok: LogoutChatGptResponse = to_response(resp).expect("deserialize logout response");
+
+    assert!(
+        !codex_home.path().join("auth.json").exists(),
+        "auth.json should be deleted"
+    );
+
+    // Verify status reflects signed-out state.
+    let status_id = mcp
+        .send_get_auth_status_request(GetAuthStatusParams {
+            include_token: Some(true),
+            refresh_token: Some(false),
+        })
+        .await
+        .expect("send getAuthStatus");
+    let status_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(status_id)),
+    )
+    .await
+    .expect("getAuthStatus timeout")
+    .expect("getAuthStatus response");
+    let status: GetAuthStatusResponse = to_response(status_resp).expect("deserialize status");
+    assert_eq!(status.auth_method, None);
+    assert_eq!(status.auth_token, None);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn login_and_cancel_chatgpt() {
+    let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
+    create_config_toml(codex_home.path()).unwrap_or_else(|err| panic!("write config.toml: {err}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let login_id = mcp
+        .send_login_chat_gpt_request()
+        .await
+        .expect("send loginChatGpt");
+    let login_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(login_id)),
+    )
+    .await
+    .expect("loginChatGpt timeout")
+    .expect("loginChatGpt response");
+    let login: LoginChatGptResponse = to_response(login_resp).expect("deserialize login resp");
+
+    let cancel_id = mcp
+        .send_cancel_login_chat_gpt_request(CancelLoginChatGptParams {
+            login_id: login.login_id,
+        })
+        .await
+        .expect("send cancelLoginChatGpt");
+    let cancel_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(cancel_id)),
+    )
+    .await
+    .expect("cancelLoginChatGpt timeout")
+    .expect("cancelLoginChatGpt response");
+    let _ok: CancelLoginChatGptResponse =
+        to_response(cancel_resp).expect("deserialize cancel response");
+
+    // Optionally observe the completion notification; do not fail if it races.
+    let maybe_note = timeout(
+        Duration::from_secs(2),
+        mcp.read_stream_until_notification_message("codex/event/login_chat_gpt_complete"),
+    )
+    .await;
+    if maybe_note.is_err() {
+        eprintln!("warning: did not observe login_chat_gpt_complete notification after cancel");
+    }
+}

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

@@ -0,0 +1,13 @@
+mod archive_conversation;
+mod auth;
+mod codex_message_processor_flow;
+mod config;
+mod create_conversation;
+mod fuzzy_file_search;
+mod interrupt;
+mod list_resume;
+mod login;
+mod send_message;
+mod set_default_model;
+mod user_agent;
+mod user_info;

codex-rs/app-server/tests/suite/send_message.rs

@@ -0,0 +1,186 @@
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::create_final_assistant_message_sse_response;
+use app_test_support::create_mock_chat_completions_server;
+use app_test_support::to_response;
+use codex_protocol::mcp_protocol::AddConversationListenerParams;
+use codex_protocol::mcp_protocol::AddConversationSubscriptionResponse;
+use codex_protocol::mcp_protocol::ConversationId;
+use codex_protocol::mcp_protocol::InputItem;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::NewConversationResponse;
+use codex_protocol::mcp_protocol::SendUserMessageParams;
+use codex_protocol::mcp_protocol::SendUserMessageResponse;
+use mcp_types::JSONRPCNotification;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test]
+async fn test_send_message_success() {
+    // Spin up a mock completions server that immediately ends the Codex turn.
+    // Two Codex turns hit the mock model (session start + send-user-message). Provide two SSE responses.
+    let responses = vec![
+        create_final_assistant_message_sse_response("Done").expect("build mock assistant message"),
+        create_final_assistant_message_sse_response("Done").expect("build mock assistant message"),
+    ];
+    let server = create_mock_chat_completions_server(responses).await;
+
+    // Create a temporary Codex home with config pointing at the mock server.
+    let codex_home = TempDir::new().expect("create temp dir");
+    create_config_toml(codex_home.path(), &server.uri()).expect("write config.toml");
+
+    // Start MCP server process and initialize.
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timed out")
+        .expect("init failed");
+
+    // Start a conversation using the new wire API.
+    let new_conv_id = mcp
+        .send_new_conversation_request(NewConversationParams::default())
+        .await
+        .expect("send newConversation");
+    let new_conv_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_conv_id)),
+    )
+    .await
+    .expect("newConversation timeout")
+    .expect("newConversation resp");
+    let NewConversationResponse {
+        conversation_id, ..
+    } = to_response::<_>(new_conv_resp).expect("deserialize newConversation response");
+
+    // 2) addConversationListener
+    let add_listener_id = mcp
+        .send_add_conversation_listener_request(AddConversationListenerParams { conversation_id })
+        .await
+        .expect("send addConversationListener");
+    let add_listener_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(add_listener_id)),
+    )
+    .await
+    .expect("addConversationListener timeout")
+    .expect("addConversationListener resp");
+    let AddConversationSubscriptionResponse { subscription_id: _ } =
+        to_response::<_>(add_listener_resp).expect("deserialize addConversationListener response");
+
+    // Now exercise sendUserMessage twice.
+    send_message("Hello", conversation_id, &mut mcp).await;
+    send_message("Hello again", conversation_id, &mut mcp).await;
+}
+
+#[expect(clippy::expect_used)]
+async fn send_message(message: &str, conversation_id: ConversationId, mcp: &mut McpProcess) {
+    // Now exercise sendUserMessage.
+    let send_id = mcp
+        .send_send_user_message_request(SendUserMessageParams {
+            conversation_id,
+            items: vec![InputItem::Text {
+                text: message.to_string(),
+            }],
+        })
+        .await
+        .expect("send sendUserMessage");
+
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(send_id)),
+    )
+    .await
+    .expect("sendUserMessage response timeout")
+    .expect("sendUserMessage response error");
+
+    let _ok: SendUserMessageResponse = to_response::<SendUserMessageResponse>(response)
+        .expect("deserialize sendUserMessage response");
+
+    // Verify the task_finished notification is received.
+    // Note this also ensures that the final request to the server was made.
+    let task_finished_notification: JSONRPCNotification = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("codex/event/task_complete"),
+    )
+    .await
+    .expect("task_finished_notification timeout")
+    .expect("task_finished_notification resp");
+    let serde_json::Value::Object(map) = task_finished_notification
+        .params
+        .expect("notification should have params")
+    else {
+        panic!("task_finished_notification should have params");
+    };
+    assert_eq!(
+        map.get("conversationId")
+            .expect("should have conversationId"),
+        &serde_json::Value::String(conversation_id.to_string())
+    );
+}
+
+#[tokio::test]
+async fn test_send_message_session_not_found() {
+    // Start MCP without creating a Codex session
+    let codex_home = TempDir::new().expect("tempdir");
+    let mut mcp = McpProcess::new(codex_home.path()).await.expect("spawn");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("timeout")
+        .expect("init");
+
+    let unknown = ConversationId::new();
+    let req_id = mcp
+        .send_send_user_message_request(SendUserMessageParams {
+            conversation_id: unknown,
+            items: vec![InputItem::Text {
+                text: "ping".to_string(),
+            }],
+        })
+        .await
+        .expect("send sendUserMessage");
+
+    // Expect an error response for unknown conversation.
+    let err = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_error_message(RequestId::Integer(req_id)),
+    )
+    .await
+    .expect("timeout")
+    .expect("error");
+    assert_eq!(err.id, RequestId::Integer(req_id));
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+fn create_config_toml(codex_home: &Path, server_uri: &str) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        format!(
+            r#"
+model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "danger-full-access"
+
+model_provider = "mock_provider"
+
+[model_providers.mock_provider]
+name = "Mock provider for test"
+base_url = "{server_uri}/v1"
+wire_api = "chat"
+request_max_retries = 0
+stream_max_retries = 0
+"#
+        ),
+    )
+}

codex-rs/app-server/tests/suite/set_default_model.rs

@@ -0,0 +1,76 @@
+use std::path::Path;
+
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_core::config::ConfigToml;
+use codex_protocol::mcp_protocol::SetDefaultModelParams;
+use codex_protocol::mcp_protocol::SetDefaultModelResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn set_default_model_persists_overrides() {
+    let codex_home = TempDir::new().expect("create tempdir");
+    create_config_toml(codex_home.path()).expect("write config.toml");
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("init timeout")
+        .expect("init failed");
+
+    let params = SetDefaultModelParams {
+        model: Some("gpt-4.1".to_string()),
+        reasoning_effort: None,
+    };
+
+    let request_id = mcp
+        .send_set_default_model_request(params)
+        .await
+        .expect("send setDefaultModel");
+
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("setDefaultModel timeout")
+    .expect("setDefaultModel response");
+
+    let _: SetDefaultModelResponse =
+        to_response(resp).expect("deserialize setDefaultModel response");
+
+    let config_path = codex_home.path().join("config.toml");
+    let config_contents = tokio::fs::read_to_string(&config_path)
+        .await
+        .expect("read config.toml");
+    let config_toml: ConfigToml = toml::from_str(&config_contents).expect("parse config.toml");
+
+    assert_eq!(
+        ConfigToml {
+            model: Some("gpt-4.1".to_string()),
+            model_reasoning_effort: None,
+            ..Default::default()
+        },
+        config_toml,
+    );
+}
+
+// Helper to create a config.toml; mirrors create_conversation.rs
+fn create_config_toml(codex_home: &Path) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(
+        config_toml,
+        r#"
+model = "gpt-5-codex"
+model_reasoning_effort = "medium"
+"#,
+    )
+}

codex-rs/app-server/tests/suite/user_agent.rs

@@ -0,0 +1,50 @@
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_protocol::mcp_protocol::GetUserAgentResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_user_agent_returns_current_codex_user_agent() {
+    let codex_home = TempDir::new().unwrap_or_else(|err| panic!("create tempdir: {err}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("initialize timeout")
+        .expect("initialize request");
+
+    let request_id = mcp
+        .send_get_user_agent_request()
+        .await
+        .expect("send getUserAgent");
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getUserAgent timeout")
+    .expect("getUserAgent response");
+
+    let os_info = os_info::get();
+    let user_agent = format!(
+        "codex_cli_rs/0.0.0 ({} {}; {}) {} (codex-app-server-tests; 0.1.0)",
+        os_info.os_type(),
+        os_info.version(),
+        os_info.architecture().unwrap_or("unknown"),
+        codex_core::terminal::user_agent()
+    );
+
+    let received: GetUserAgentResponse =
+        to_response(response).expect("deserialize getUserAgent response");
+    let expected = GetUserAgentResponse { user_agent };
+
+    assert_eq!(received, expected);
+}

codex-rs/app-server/tests/suite/user_info.rs

@@ -0,0 +1,78 @@
+use std::time::Duration;
+
+use anyhow::Context;
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use base64::Engine;
+use base64::engine::general_purpose::URL_SAFE_NO_PAD;
+use codex_core::auth::AuthDotJson;
+use codex_core::auth::get_auth_file;
+use codex_core::auth::write_auth_json;
+use codex_core::token_data::IdTokenInfo;
+use codex_core::token_data::TokenData;
+use codex_protocol::mcp_protocol::UserInfoResponse;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn user_info_returns_email_from_auth_json() {
+    let codex_home = TempDir::new().expect("create tempdir");
+
+    let auth_path = get_auth_file(codex_home.path());
+    let mut id_token = IdTokenInfo::default();
+    id_token.email = Some("user@example.com".to_string());
+    id_token.raw_jwt = encode_id_token_with_email("user@example.com").expect("encode id token");
+
+    let auth = AuthDotJson {
+        openai_api_key: None,
+        tokens: Some(TokenData {
+            id_token,
+            access_token: "access".to_string(),
+            refresh_token: "refresh".to_string(),
+            account_id: None,
+        }),
+        last_refresh: None,
+    };
+    write_auth_json(&auth_path, &auth).expect("write auth.json");
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("initialize timeout")
+        .expect("initialize request");
+
+    let request_id = mcp.send_user_info_request().await.expect("send userInfo");
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("userInfo timeout")
+    .expect("userInfo response");
+
+    let received: UserInfoResponse = to_response(response).expect("deserialize userInfo response");
+    let expected = UserInfoResponse {
+        alleged_user_email: Some("user@example.com".to_string()),
+    };
+
+    assert_eq!(received, expected);
+}
+
+fn encode_id_token_with_email(email: &str) -> anyhow::Result<String> {
+    let header_b64 = URL_SAFE_NO_PAD.encode(
+        serde_json::to_vec(&json!({ "alg": "none", "typ": "JWT" }))
+            .context("serialize jwt header")?,
+    );
+    let payload =
+        serde_json::to_vec(&json!({ "email": email })).context("serialize jwt payload")?;
+    let payload_b64 = URL_SAFE_NO_PAD.encode(payload);
+    Ok(format!("{header_b64}.{payload_b64}.signature"))
+}