refactors HistoryCell to be a trait instead of an enum. Also collapse
the many "degenerate" HistoryCell enums which were just a store of lines
into a single PlainHistoryCell type.
The goal here is to allow more ways of rendering history cells (e.g.
expanded/collapsed/"live"), and I expect we will return to more varied
types of HistoryCell as we develop this area.
Historically, `Codex::spawn()` would create the instance of `Codex` and
enforce, by construction, that `Op::ConfigureSession` was the first `Op`
submitted via `submit()`. Then over in `submission_loop()`, it would
handle the case for taking the parameters of `Op::ConfigureSession` and
turning it into a `Session`.
This approach has two challenges from a state management perspective:
https://github.com/openai/codex/blob/f968a1327ad39a7786759ea8f1d1c088fe41e91b/codex-rs/core/src/codex.rs#L718
- The local `sess` variable in `submission_loop()` has to be `mut` and
`Option<Arc<Session>>` because it is not invariant that a `Session` is
present for the lifetime of the loop, so there is a lot of logic to deal
with the case where `sess` is `None` (e.g., the `send_no_session_event`
function and all of its callsites).
- `submission_loop()` is written in such a way that
`Op::ConfigureSession` could be observed multiple times, but in
practice, it is only observed exactly once at the start of the loop.
In this PR, we try to simplify the state management by _removing_ the
`Op::ConfigureSession` enum variant and constructing the `Session` as
part of `Codex::spawn()` so that it can be passed to `submission_loop()`
as `Arc<Session>`. The original logic from the `Op::ConfigureSession`
has largely been moved to the new `Session::new()` constructor.
---
Incidentally, I also noticed that the handling of `Op::ConfigureSession`
can result in events being dispatched in addition to
`EventMsg::SessionConfigured`, as an `EventMsg::Error` is created for
every MCP initialization error, so it is important to preserve that
behavior:
https://github.com/openai/codex/blob/f968a1327ad39a7786759ea8f1d1c088fe41e91b/codex-rs/core/src/codex.rs#L901-L916
Though admittedly, I believe this does not play nice with #2264, as
these error messages will likely be dispatched before the client has a
chance to call `addConversationListener`, so we likely need to make it
so `newConversation` automatically creates the subscription, but we must
also guarantee that the "ack" from `newConversation` is returned before
any other conversation-related notifications are sent so the client
knows what `conversation_id` to match on.
As `Session` needs a bit of work, it will make things easier to move
around if we can start by reducing the extent of its public API. This
makes all the fields private, though adds three `pub(crate)` getters.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/2285).
* #2287
* #2286
* __->__ #2285
Sometimes COT is returns as text content instead of `ReasoningText`. We
should parse it but not serialize back on requests.
---------
Co-authored-by: Ahmed Ibrahim <aibrahim@openai.com>
This updates `CodexMessageProcessor` so that each notification it sends
for a `EventMsg` from a `CodexConversation` such that:
- The `params` always has an appropriate `conversationId` field.
- The `method` is now includes the name of the `EventMsg` type rather
than using `codex/event` as the `method` type for all notifications. (We
currently prefix the method name with `codex/event/`, but I think that
should go away once we formalize the notification schema in
`wire_format.rs`.)
As part of this, we update `test_codex_jsonrpc_conversation_flow()` to
verify that the `task_finished` notification has made it through the
system instead of sleeping for 5s and "hoping" the server finished
processing the task. Note we have seen some flakiness in some of our
other, similar integration tests, and I expect adding a similar check
would help in those cases, as well.
This introduces a new set of request types that our `codex mcp`
supports. Note that these do not conform to MCP tool calls so that
instead of having to send something like this:
```json
{
"jsonrpc": "2.0",
"method": "tools/call",
"id": 42,
"params": {
"name": "newConversation",
"arguments": {
"model": "gpt-5",
"approvalPolicy": "on-request"
}
}
}
```
we can send something like this:
```json
{
"jsonrpc": "2.0",
"method": "newConversation",
"id": 42,
"params": {
"model": "gpt-5",
"approvalPolicy": "on-request"
}
}
```
Admittedly, this new format is not a valid MCP tool call, but we are OK
with that right now. (That is, not everything we might want to request
of `codex mcp` is something that is appropriate for an autonomous agent
to do.)
To start, this introduces four request types:
- `newConversation`
- `sendUserMessage`
- `addConversationListener`
- `removeConversationListener`
The new `mcp-server/tests/codex_message_processor_flow.rs` shows how
these can be used.
The types are defined on the `CodexRequest` enum, so we introduce a new
`CodexMessageProcessor` that is responsible for dealing with requests
from this enum. The top-level `MessageProcessor` has been updated so
that when `process_request()` is called, it first checks whether the
request conforms to `CodexRequest` and dispatches it to
`CodexMessageProcessor` if so.
Note that I also decided to use `camelCase` for the on-the-wire format,
as that seems to be the convention for MCP.
For the moment, the new protocol is defined in `wire_format.rs` within
the `mcp-server` crate, but in a subsequent PR, I will probably move it
to its own crate to ensure the protocol has minimal dependencies and
that we can codegen a schema from it.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/2264).
* #2278
* __->__ #2264
## Summary
- enable reasoning for any model slug starting with `codex-`
- provide default model info for `codex-*` slugs
- test that codex models are detected and support reasoning
## Testing
- `just fmt`
- `just fix` *(fails: E0658 `let` expressions in this position are
unstable)*
- `cargo test --all-features` *(fails: E0658 `let` expressions in this
position are unstable)*
------
https://chatgpt.com/codex/tasks/task_i_689d13f8705483208a6ed21c076868e1
Michael Bolin