Files
llmx/codex-rs/app-server/tests/suite/codex_message_processor_flow.rs
Michael Bolin d9dbf48828 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`.
2025-09-30 07:06:18 +00:00

373 lines
14 KiB
Rust

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
"#
),
)
}