codex

[App-server] add new v2 events:item/reasoning/delta, item/agentMessage/delta & item/reasoning/summaryPartAdded (#6559 )

core event to app server event mapping:
1. `codex/event/reasoning_content_delta` ->
`item/reasoning/summaryTextDelta`.
2. `codex/event/reasoning_raw_content_delta` ->
`item/reasoning/textDelta`
3. `codex/event/agent_message_content_delta` →
`item/agentMessage/delta`.
4. `codex/event/agent_reasoning_section_break` ->
`item/reasoning/summaryPartAdded`.

Also added a change in core to pass down content index, summary index
and item id from events.

Tested with the `git checkout owen/app_server_test_client && cargo run
-p codex-app-server-test-client -- send-message-v2 "hello"` and verified
that new events are emitted correctly.

Celia Chen · 2025-11-14 00:25:01 +00:00

b8ec97c0ef

[app-server] feat: thread/resume supports history, path, and overrides (#6483 )

This updates `thread/resume` to be at parity with v1's
`ResumeConversationParams`. Turns out history is useful for codex cloud
and path is useful for the VSCode extension. And config overrides are
always useful.

Owen Lin · 2025-11-12 22:02:43 +00:00

964220ac94

[app-server] add item started/completed events for turn items (#6517 )

This one should be quite straightforward, as it's just a translation of
TurnItem events we already emit to ThreadItem that app-server exposes to
customers.

To test, cp my change to owen/app_server_test_client and do the
following:
```
cargo build -p codex-cli
RUST_LOG=codex_app_server=info CODEX_BIN=target/debug/codex cargo run -p codex-app-server-test-client -- send-message-v2 "hello"
```

example event before (still kept there for backward compatibility):
```
{
<   "method": "codex/event/item_completed",
<   "params": {
<     "conversationId": "019a74cc-fad9-7ab3-83a3-f42827b7b074",
<     "id": "0",
<     "msg": {
<       "item": {
<         "Reasoning": {
<           "id": "rs_03d183492e07e20a016913a936eb8c81a1a7671a103fee8afc",
<           "raw_content": [],
<           "summary_text": [
<             "Hey! What would you like to work on? I can explore the repo, run specific tests, or implement a change. Let's keep it short and straightforward. There's no need for a lengthy introduction or elaborate planning, just a friendly greeting and an open offer to help. I want to make sure the user feels welcomed and understood right from the start. It's all about keeping the tone friendly and concise!"
<           ]
<         }
<       },
<       "thread_id": "019a74cc-fad9-7ab3-83a3-f42827b7b074",
<       "turn_id": "0",
<       "type": "item_completed"
<     }
<   }
< }
```

after (v2):
```
< {
<   "method": "item/completed",
<   "params": {
<     "item": {
<       "id": "rs_03d183492e07e20a016913a936eb8c81a1a7671a103fee8afc",
<       "text": "Hey! What would you like to work on? I can explore the repo, run specific tests, or implement a change. Let's keep it short and straightforward. There's no need for a lengthy introduction or elaborate planning, just a friendly greeting and an open offer to help. I want to make sure the user feels welcomed and understood right from the start. It's all about keeping the tone friendly and concise!",
<       "type": "reasoning"
<     }
<   }
< }
```

Celia Chen · 2025-11-11 22:43:24 +00:00

e357fc723d

[hygiene][app-server] have a helper function for duplicate code in turn APIs (#6488 )

turn_start and turn_interrupt have some logic that can be shared. have a
helper function for it.

Celia Chen · 2025-11-11 02:44:47 +00:00

6951872776

[app-server] feat: expose additional fields on Thread (#6338 )

Add the following fields to Thread:

```
    pub preview: String,
    pub model_provider: String,
    pub created_at: i64,
```

Will prob need another PR once this lands:
https://github.com/openai/codex/pull/6337

Owen Lin · 2025-11-07 04:08:45 +00:00

2030b28083

[App-server] Implement account/read endpoint (#6336 )

This PR does two things:
1. add a new function in core that maps the core-internal plan type to
the external plan type;
2. implement account/read that get account status (v2 of
`getAuthStatus`).

Celia Chen · 2025-11-06 19:43:13 -08:00

e84e39940b

[App Server] Add more session metadata to listConversations (#6337 )

This unlocks a few new product experience for app server consumers

Gabriel Peal · 2025-11-06 17:13:24 -05:00

1b8cc8b625

[app-server] feat: v2 Turn APIs (#6216 )

Implements:
```
turn/start
turn/interrupt
```

along with their integration tests. These are relatively light wrappers
around the existing core logic, and changes to core logic are minimal.

However, an improvement made for developer ergonomics:
- `turn/start` replaces both `SendUserMessage` (no turn overrides) and
`SendUserTurn` (can override model, approval policy, etc.)

Owen Lin · 2025-11-06 16:36:36 +00:00

6582554926

feat: support models with single reasoning effort (#6300 )

Thibault Sottiaux · 2025-11-05 23:06:45 -08:00

667e841d3e

[App-server] Add account/login/cancel v2 endpoint (#6288 )

Add `account/login/cancel` v2 endpoint for auth. this is similar
implementation to `cancelLoginChatgpt` v1 endpoint.

Celia Chen · 2025-11-06 01:13:55 +00:00

229d18f4d2

[App-server] Implement v2 for account/login/start and account/login/completed (#6183 )

This PR implements `account/login/start` and `account/login/completed`.
Instead of having separate endpoints for login with chatgpt and api, we
have a single enum handling different login methods. For sync auth
methods like sign in with api key, we still send a `completed`
notification back to be compatible with the async login flow.

Celia Chen · 2025-11-05 13:52:50 -08:00

05f0b4f590

[app-server] feat: v2 Thread APIs (#6214 )

Implements:
```
thread/list
thread/start
thread/resume
thread/archive
```

along with their integration tests. These are relatively light wrappers
around the existing core logic, and changes to core logic are minimal.

However, an improvement made for developer ergonomics:
- `thread/start` and `thread/resume` automatically attaches a
conversation listener internally, so clients don't have to make a
separate `AddConversationListener` call like they do today.

For consistency, also updated `model/list` and `feedback/upload` (naming
conventions, list API params).

Owen Lin · 2025-11-05 20:28:43 +00:00

2ab1650d4d

[app-server] feat: export.rs supports a v2 namespace, initial v2 notifications (#6212 )

**Typescript and JSON schema exports**
While working on Thread/Turn/Items type definitions, I realize we will
run into name conflicts between v1 and v2 APIs (e.g. `RateLimitWindow`
which won't be reusable since v1 uses `RateLimitWindow` from `protocol/`
which uses snake_case, but we want to expose camelCase everywhere, so
we'll define a V2 version of that struct that serializes as camelCase).

To set us up for a clean and isolated v2 API, generate types into a
`v2/` namespace for both typescript and JSON schema.
- TypeScript: v2 types emit under `out_dir/v2/*.ts`, and root index.ts
now re-exports them via `export * as v2 from "./v2"`;.
- JSON Schemas: v2 definitions bundle under `#/definitions/v2/*` rather
than the root.

The location for the original types (v1 and types pulled from
`protocol/` and other core crates) haven't changed and are still at the
root. This is for backwards compatibility: no breaking changes to
existing usages of v1 APIs and types.

**Notifications**
While working on export.rs, I:
- refactored server/client notifications with macros (like we already do
for methods) so they also get exported (I noticed they weren't being
exported at all).
- removed the hardcoded list of types to export as JSON schema by
leveraging the existing macros instead
- and took a stab at API V2 notifications. These aren't wired up yet,
and I expect to iterate on these this week.

Owen Lin · 2025-11-05 01:02:39 +00:00

edf4c3f627

[App-server] v2 for account/updated and account/logout (#6175 )

V2 for `account/updated` and `account/logout` for app server. correspond
to old `authStatusChange` and `LogoutChatGpt` respectively. Followup PRs
will make other v2 endpoints call `account/updated` instead of
`authStatusChange` too.

Celia Chen · 2025-11-03 22:01:33 -08:00

d3187dbc17

Fix "archive conversation" on Windows (#6124 )

Addresses issue https://github.com/openai/codex/issues/3582 where an
"archive conversation" command in the extension fails on Windows.

The problem is that the `archive_conversation` api server call is not
canonicalizing the path to the rollout path when performing its check to
verify that the rollout path is in the sessions directory. This causes
it to fail 100% of the time on Windows.

Testing: I was able to repro the error on Windows 100% prior to this
change. After the change, I'm no longer able to repro.

Eric Traut · 2025-11-02 21:41:05 -08:00

dccce34d84

[Hygiene] Remove include_view_image_tool config (#5976 )

There's still some debate about whether we want to expose
`tools.view_image` or `feature.view_image` so those are left unchanged
for now, but this old `include_view_image_tool` config is good-to-go.
Also updated the doc to reflect that `view_image` tool is now by default
true.

Celia Chen · 2025-10-30 13:23:24 -07:00

6ef658a9f9

[codex] add developer instructions (#5897 )

we are using developer instructions for code reviews, we need to pass
them in cli as well.

Anton Panasenko · 2025-10-30 11:18:31 -07:00

9572cfc782

feat: compaction prompt configurable (#5959 )

```
 codex -c compact_prompt="Summarize in bullet points"
 ```

jif-oai · 2025-10-30 14:24:24 +00:00

f4f9695978

chore: unify config crates (#5958 )

jif-oai · 2025-10-30 10:28:32 +00:00

aa76003e28

chore: config editor (#5878 )

The goal is to have a single place where we actually write files

In a follow-up PR, will move everything config related in a dedicated
module and move the helpers in a dedicated file

jif-oai · 2025-10-29 20:52:46 +00:00

db31f6966d

[codex][app-server] resume conversation from history (#5893 )

Anton Panasenko · 2025-10-28 18:18:03 -07:00

149e198ce8

[App Server] Allow fetching or resuming a conversation summary from the conversation id (#5890 )

This PR adds an option to app server to allow conversation summaries to
be fetched from just the conversation id rather than rollout path for
convenience at the cost of some latency to discover the rollout path.

This convenience is non-trivial as it allows app servers to simply
maintain conversation ids rather than rollout paths and the associated
platform (Windows) handling associated with storing and encoding them
correctly.

Gabriel Peal · 2025-10-28 20:17:22 -04:00

1d76ba5ebe

[Auth] Choose which auth storage to use based on config (#5792 )

This PR is a follow-up to #5591. It allows users to choose which auth
storage mode they want by using the new
`cli_auth_credentials_store_mode` config.

Celia Chen · 2025-10-27 19:41:49 -07:00

4a42c4e142

[Auth] Introduce New Auth Storage Abstraction for Codex CLI (#5569 )

This PR introduces a new `Auth Storage` abstraction layer that takes
care of read, write, and load of auth tokens based on the
AuthCredentialsStoreMode. It is similar to how we handle MCP client
oauth
[here](https://github.com/openai/codex/blob/main/codex-rs/rmcp-client/src/oauth.rs).
Instead of reading and writing directly from disk for auth tokens, Codex
CLI workflows now should instead use this auth storage using the public
helper functions.

This PR is just a refactor of the current code so the behavior stays the
same. We will add support for keyring and hybrid mode in follow-up PRs.

I have read the CLA Document and I hereby sign the CLA

Celia Chen · 2025-10-27 11:01:14 -07:00

eb5b1b627f

feat: introduce GetConversationSummary RPC (#5803 )

This adds an RPC to the app server to the the `ConversationSummary` via
a rollout path. Now that the VS Code extension supports showing the
Codex UI in an editor panel where the URI of the panel maps to the
rollout file, we need to be able to get the `ConversationSummary` from
the rollout file directly.

Michael Bolin · 2025-10-27 09:11:45 -07:00

5ee8a17b4e

feat: update NewConversationParams to take an optional model_provider (#5793 )

An AppServer client should be able to use any (`model_provider`, `model`) in the user's config. `NewConversationParams` already supported specifying the `model`, but this PR expands it to support `model_provider`, as well.

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/5793).
* #5803
* __->__ #5793

Michael Bolin · 2025-10-27 09:33:30 +00:00

15fa2283e7

feat: annotate conversations with model_provider for filtering (#5658 )

Because conversations that use the Responses API can have encrypted
reasoning messages, trying to resume a conversation with a different
provider could lead to confusing "failed to decrypt" errors. (This is
reproducible by starting a conversation using ChatGPT login and resuming
it as a conversation that uses OpenAI models via Azure.)

This changes `ListConversationsParams` to take a `model_providers:
Option<Vec<String>>` and adds `model_provider` on each
`ConversationSummary` it returns so these cases can be disambiguated.

Note this ended up making changes to
`codex-rs/core/src/rollout/tests.rs` because it had a number of cases
where it expected `Some` for the value of `next_cursor`, but the list of
rollouts was complete, so according to this docstring:


https://github.com/openai/codex/blob/bcd64c7e7231d6316a2377d1525a0fa74f21b783/codex-rs/app-server-protocol/src/protocol.rs#L334-L337

If there are no more items to return, then `next_cursor` should be
`None`. This PR updates that logic.






---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/5658).
* #5803
* #5793
* __->__ #5658

Michael Bolin · 2025-10-27 02:03:30 -07:00

5907422d65

Add feedback upload request handling (#5682 )

Ahmed Ibrahim · 2025-10-27 05:53:39 +00:00

f178805252

[codex][app-server] introduce codex/event/raw_item events (#5578 )

Anton Panasenko · 2025-10-24 22:41:52 +00:00

6af83d86ff

Added model summary and risk assessment for commands that violate sandbox policy (#5536 )

This PR adds support for a model-based summary and risk assessment for
commands that violate the sandbox policy and require user approval. This
aids the user in evaluating whether the command should be approved.

The feature works by taking a failed command and passing it back to the
model and asking it to summarize the command, give it a risk level (low,
medium, high) and a risk category (e.g. "data deletion" or "data
exfiltration"). It uses a new conversation thread so the context in the
existing thread doesn't influence the answer. If the call to the model
fails or takes longer than 5 seconds, it falls back to the current
behavior.

For now, this is an experimental feature and is gated by a config key
`experimental_sandbox_command_assessment`.

Here is a screen shot of the approval prompt showing the risk assessment
and summary.

<img width="723" height="282" alt="image"
src="https://github.com/user-attachments/assets/4597dd7c-d5a0-4e9f-9d13-414bd082fd6b"
/>

Eric Traut · 2025-10-24 15:23:44 -07:00

f8af4f5c8d

[app-server] add new account method API stubs (#5527 )

These are the schema definitions for the new JSON-RPC APIs associated
with accounts. These are not wired up to business logic yet and will
currently throw an internal error indicating these are unimplemented.

Owen Lin · 2025-10-22 15:36:11 -07:00

aee321f62b

[app-server] send account/rateLimits/updated notifications (#5477 )

Codex will now send an `account/rateLimits/updated` notification
whenever the user's rate limits are updated.

This is implemented by just transforming the existing TokenCount event.

Owen Lin · 2025-10-22 20:12:40 +00:00

8ae3949072

Add new thread items and rewire event parsing to use them (#5418 )

1. Adds AgentMessage,  Reasoning,  WebSearch items.
2. Switches the ResponseItem parsing to use new items and then also emit
3. Removes user-item kind and filters out "special" (environment) user
items when returning to clients.

pakrym-oai · 2025-10-22 10:14:50 -07:00

3c90728a29

[app-server] model/list API (#5382 )

Adds a `model/list` paginated API that returns the list of models
supported by Codex.

Owen Lin · 2025-10-21 11:15:17 -07:00

26f314904a

Enable plan tool by default (#5384 )

## Summary
- make the plan tool available by default by removing the feature flag
and always registering the handler
- drop plan-tool CLI and API toggles across the exec, TUI, MCP server,
and app server code paths
- update tests and configs to reflect the always-on plan tool and guard
workspace restriction tests against env leakage

## Testing
Manually tested the extension. 
------
https://chatgpt.com/codex/tasks/task_i_68f67a3ff2d083209562a773f814c1f9

pakrym-oai · 2025-10-21 16:25:05 +00:00

1b10a3a1b2

[app-server] read rate limits API (#5302 )

Adds a `GET account/rateLimits/read` API to app-server. This calls the
codex backend to fetch the user's current rate limits.

This would be helpful in checking rate limits without having to send a
message.

For calling the codex backend usage API, I generated the types and
manually copied the relevant ones into `codex-backend-openapi-types`.
It'll be nice to extend our internal openapi generator to support Rust
so we don't have to run these manual steps.

# External (non-OpenAI) Pull Request Requirements

Before opening this Pull Request, please read the dedicated
"Contributing" markdown file or your PR may be closed:
https://github.com/openai/codex/blob/main/docs/contributing.md

If your PR conforms to our contribution guidelines, replace this text
with a detailed and high quality description of your changes.

Owen Lin · 2025-10-20 14:11:54 -07:00

5c680c6587

Add ItemStarted/ItemCompleted events for UserInputItem (#5306 )

Adds a new ItemStarted event and delivers UserMessage as the first item
type (more to come).


Renames `InputItem` to `UserInput` considering we're using the `Item`
suffix for actual items.

pakrym-oai · 2025-10-20 13:34:44 -07:00

9c903c4716

chore: rework tools execution workflow (#5278 )

Re-work the tool execution flow. Read `orchestrator.rs` to understand
the structure

jif-oai · 2025-10-20 20:57:37 +01:00

5e4f3bbb0b

Add forced_chatgpt_workspace_id and forced_login_method configuration options (#5303 )

This PR adds support for configs to specify a forced login method
(chatgpt or api) as well as a forced chatgpt account id. This lets
enterprises uses [managed
configs](https://developers.openai.com/codex/security#managed-configuration)
to force all employees to use their company's workspace instead of their
own or any other.

When a workspace id is set, a query param is sent to the login flow
which auto-selects the given workspace or errors if the user isn't a
member of it.

This PR is large but a large % of it is tests, wiring, and required
formatting changes.

API login with chatgpt forced
<img width="1592" height="116" alt="CleanShot 2025-10-19 at 22 40 04"
src="https://github.com/user-attachments/assets/560c6bb4-a20a-4a37-95af-93df39d057dd"
/>

ChatGPT login with api forced
<img width="1018" height="100" alt="CleanShot 2025-10-19 at 22 40 29"
src="https://github.com/user-attachments/assets/d010bbbb-9c8d-4227-9eda-e55bf043b4af"
/>

Onboarding with api forced
<img width="892" height="460" alt="CleanShot 2025-10-19 at 22 41 02"
src="https://github.com/user-attachments/assets/cc0ed45c-b257-4d62-a32e-6ca7514b5edd"
/>

Onboarding with ChatGPT forced
<img width="1154" height="426" alt="CleanShot 2025-10-19 at 22 41 27"
src="https://github.com/user-attachments/assets/41c41417-dc68-4bb4-b3e7-3b7769f7e6a1"
/>

Logging in with the wrong workspace
<img width="2222" height="84" alt="CleanShot 2025-10-19 at 22 42 31"
src="https://github.com/user-attachments/assets/0ff4222c-f626-4dd3-b035-0b7fe998a046"
/>

Gabriel Peal · 2025-10-20 08:50:54 -07:00

d87f87e25b

feat: add --add-dir flag for extra writable roots (#5335 )

Add a `--add-dir` CLI flag so sessions can use extra writable roots in
addition to the ones specified in the config file. These are ephemerally
added during the session only.

Fixes #3303
Fixes #2797

Thibault Sottiaux · 2025-10-18 22:13:53 -07:00

4f46360aa4

feat: add Vec<ParsedCommand> to ExecApprovalRequestEvent (#5222 )

This adds `parsed_cmd: Vec<ParsedCommand>` to `ExecApprovalRequestEvent`
in the core protocol (`protocol/src/protocol.rs`), which is also what
this field is named on `ExecCommandBeginEvent`. Honestly, I don't love
the name (it sounds like a single command, but it is actually a list of
them), but I don't want to get distracted by a naming discussion right
now.

This also adds `parsed_cmd` to `ExecCommandApprovalParams` in
`codex-rs/app-server-protocol/src/protocol.rs`, so it will be available
via `codex app-server`, as well.

For consistency, I also updated `ExecApprovalElicitRequestParams` in
`codex-rs/mcp-server/src/exec_approval.rs` to include this field under
the name `codex_parsed_cmd`, as that struct already has a number of
special `codex_*` fields. Note this is the code for when Codex is used
as an MCP _server_ and therefore has to conform to the official spec for
an MCP elicitation type.

Michael Bolin · 2025-10-15 13:58:40 -07:00

995f5c3614

add(core): managed config (#3868 )

## Summary

- Factor `load_config_as_toml` into `core::config_loader` so config
loading is reusable across callers.
- Layer `~/.codex/config.toml`, optional `~/.codex/managed_config.toml`,
and macOS managed preferences (base64) with recursive table merging and
scoped threads per source.

## Config Flow

```
Managed prefs (macOS profile: com.openai.codex/config_toml_base64)
                               ▲
                               │
~/.codex/managed_config.toml   │  (optional file-based override)
                               ▲
                               │
                ~/.codex/config.toml (user-defined settings)
```

- The loader searches under the resolved `CODEX_HOME` directory
(defaults to `~/.codex`).
- Managed configs let administrators ship fleet-wide overrides via
device profiles which is useful for enforcing certain settings like
sandbox or approval defaults.
- For nested hash tables: overlays merge recursively. Child tables are
merged key-by-key, while scalar or array values replace the prior layer
entirely. This lets admins add or tweak individual fields without
clobbering unrelated user settings.

Fouad Matin · 2025-10-03 13:02:26 -07:00

a5b7675e42

Separate interactive and non-interactive sessions (#4612 )

Do not show exec session in VSCode/TUI selector.

pakrym-oai · 2025-10-02 13:06:21 -07:00

4c566d484a

fix: remove mcp-types from app server protocol (#4537 )

We continue the separation between `codex app-server` and `codex
mcp-server`.

In particular, we introduce a new crate, `codex-app-server-protocol`,
and migrate `codex-rs/protocol/src/mcp_protocol.rs` into it, renaming it
`codex-rs/app-server-protocol/src/protocol.rs`.

Because `ConversationId` was defined in `mcp_protocol.rs`, we move it
into its own file, `codex-rs/protocol/src/conversation_id.rs`, and
because it is referenced in a ton of places, we have to touch a lot of
files as part of this PR.

We also decide to get away from proper JSON-RPC 2.0 semantics, so we
also introduce `codex-rs/app-server-protocol/src/jsonrpc_lite.rs`, which
is basically the same `JSONRPCMessage` type defined in `mcp-types`
except with all of the `"jsonrpc": "2.0"` removed.

Getting rid of `"jsonrpc": "2.0"` makes our serialization logic
considerably simpler, as we can lean heavier on serde to serialize
directly into the wire format that we use now.

Michael Bolin · 2025-10-01 02:16:26 +00:00

5881c0d6d4

fix: use macros to ensure request/response symmetry (#4529 )

Manually curating `protocol-ts/src/lib.rs` was error-prone, as expected.
I finally asked Codex to write some Rust macros so we can ensure that:

- For every variant of `ClientRequest` and `ServerRequest`, there is an
associated `params` and `response` type.
- All response types are included automatically in the output of `codex
generate-ts`.

Michael Bolin · 2025-09-30 18:06:05 -07:00

32853ecbc5

fix: ensure every variant of ClientRequest has a params field (#4512 )

This ensures changes the generated TypeScript type for `ClientRequest`
so that instead of this:

```typescript
/**
 * Request from the client to the server.
 */
export type ClientRequest =
  | { method: "initialize"; id: RequestId; params: InitializeParams }
  | { method: "newConversation"; id: RequestId; params: NewConversationParams }
  // ...
  | { method: "getUserAgent"; id: RequestId }
  | { method: "userInfo"; id: RequestId }
  // ...
```

we have this:

```typescript
/**
 * Request from the client to the server.
 */
export type ClientRequest =
  | { method: "initialize"; id: RequestId; params: InitializeParams }
  | { method: "newConversation"; id: RequestId; params: NewConversationParams }
  // ...
  | { method: "getUserAgent"; id: RequestId; params: undefined }
  | { method: "userInfo"; id: RequestId; params: undefined }
  // ...
```

which makes TypeScript happier when it comes to destructuring instances
of `ClientRequest` because it does not complain about `params` not being
guaranteed to exist anymore.

Michael Bolin · 2025-09-30 12:03:32 -07:00

6910be3224

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`.

Michael Bolin · 2025-09-30 07:06:18 +00:00

d9dbf48828

47 Commits