Commit Graph

219 Commits

  • [MCP] Remove the legacy stdio client in favor of rmcp (#5529)
    I haven't heard of any issues with the studio rmcp client so let's
    remove the legacy one and default to the new one.
    
    Any code changes are moving code from the adapter inline but there
    should be no meaningful functionality changes.
  • [MCP] Bump rmcp to 0.8.2 (#5423)
    [Release
    notes](https://github.com/modelcontextprotocol/rust-sdk/releases)
    
    Notably, this picks up two of my PRs that have four separate fixes for
    oauth dynamic client registration and auth
    https://github.com/modelcontextprotocol/rust-sdk/pull/489
    https://github.com/modelcontextprotocol/rust-sdk/pull/476
  • fix terminal corruption that could happen when onboarding and update banner (#5269)
    Instead of printing characters before booting the app, make the upgrade
    banner a history cell so it's well-behaved.
    
    <img width="771" height="586" alt="Screenshot 2025-10-16 at 4 20 51 PM"
    src="https://github.com/user-attachments/assets/90629d47-2c3d-4970-a826-283795ab34e5"
    />
    
    ---------
    
    Co-authored-by: Josh McKinney <joshka@openai.com>
  • [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.
  • tui: drop citation rendering (#4855)
    We don't instruct the model to use citations, so it never emits them.
    Further, ratatui [doesn't currently support rendering links into the
    terminal with OSC 8](https://github.com/ratatui/ratatui/issues/1028), so
    even if we did parse citations, we can't correctly render them.
    
    So, remove all the code related to rendering them.
  • chore: rework tools execution workflow (#5278)
    Re-work the tool execution flow. Read `orchestrator.rs` to understand
    the structure
  • Generate JSON schema for app-server protocol (#5063)
    Add annotations and an export script that let us generate app-server
    protocol types as typescript and JSONSchema.
    
    The script itself is a bit hacky because we need to manually label some
    of the types. Unfortunately it seems that enum variants don't get good
    names by default and end up with something like `EventMsg1`,
    `EventMsg2`, etc. I'm not an expert in this by any means, but since this
    is only run manually and we already need to enumerate the types required
    to describe the protocol, it didn't seem that much worse. An ideal
    solution here would be to have some kind of root that we could generate
    schemas for in one go, but I'm not sure if that's compatible with how we
    generate the protocol today.
  • [MCP] Add support for resources (#5239)
    This PR adds support for [MCP
    resources](https://modelcontextprotocol.io/specification/2025-06-18/server/resources)
    by adding three new tools for the model:
    1. `list_resources`
    2. `list_resource_templates`
    3. `read_resource`
    
    These 3 tools correspond to the [three primary MCP resource protocol
    messages](https://modelcontextprotocol.io/specification/2025-06-18/server/resources#protocol-messages).
    
    Example of listing and reading a GitHub resource tempalte
    <img width="2984" height="804" alt="CleanShot 2025-10-15 at 17 31 10"
    src="https://github.com/user-attachments/assets/89b7f215-2e2a-41c5-90dd-b932ac84a585"
    />
    
    `/mcp` with Figma configured
    <img width="2984" height="442" alt="CleanShot 2025-10-15 at 18 29 35"
    src="https://github.com/user-attachments/assets/a7578080-2ed2-4c59-b9b4-d8461f90d8ee"
    />
    
    Fixes #4956
  • [MCP] Allow specifying cwd and additional env vars (#5246)
    This makes stdio mcp servers more flexible by allowing users to specify
    the cwd to run the server command from and adding additional environment
    variables to be passed through to the server.
    
    Example config using the test server in this repo:
    ```toml
    [mcp_servers.test_stdio]
    cwd = "/Users/<user>/code/codex/codex-rs"
    command = "cargo"
    args = ["run", "--bin", "test_stdio_server"]
    env_vars = ["MCP_TEST_VALUE"]
    ```
    
    @bolinfest I know you hate these env var tests but let's roll with this
    for now. I may take a stab at the env guard + serial macro at some
    point.
  • fix: tui default trusted settings should respect workspace write config (#3341)
    ## Summary
    When using the trusted state during tui startup, we created a new
    WorkspaceWrite policy without checking the config.toml for a
    `sandbox_workspace_write` field. This would result in us setting the
    sandbox_mode as workspace-write, but ignoring the field if the user had
    set `sandbox_workspace_write` without also setting `sandbox_mode` in the
    config.toml. This PR adds support for respecting
    `sandbox_workspace_write` setting in config.toml in the trusted
    directory flow, and adds tests to cover this case.
    
    ## Testing
    - [x] Added unit tests
  • test: reduce time dependency on test harness (#5053)
    Tightened the CLI integration tests to stop relying on wall-clock
    sleeps—new fs watcher helper waits for session files instead of timing
    out, and SSE mocks/fixtures make the flows deterministic.
  • [MCP] Add auth status to MCP servers (#4918)
    This adds a queryable auth status for MCP servers which is useful:
    1. To determine whether a streamable HTTP server supports auth or not
    based on whether or not it supports RFC 8414-3.2
    2. Allow us to build a better user experience on top of MCP status
  • [MCP] Add support for streamable http servers with codex mcp add and replace bearer token handling (#4904)
    1. You can now add streamable http servers via the CLI
    2. As part of this, I'm also changing the existing bearer_token plain
    text config field with ane env var
    
    ```
    mcp add github --url https://api.githubcopilot.com/mcp/ --bearer-token-env-var=GITHUB_PAT
    ```
  • feat(tui): switch to tree-sitter-highlight bash highlighting (#4666)
    use tree-sitter-highlight instead of custom logic over the tree-sitter
    tree to highlight bash.
  • Set codex SDK TypeScript originator (#4894)
    ## Summary
    - ensure the TypeScript SDK sets CODEX_INTERNAL_ORIGINATOR_OVERRIDE to
    codex_sdk_ts when spawning the Codex CLI
    - extend the responses proxy test helper to capture request headers for
    assertions
    - add coverage that verifies Codex threads launched from the TypeScript
    SDK send the codex_sdk_ts originator header
    
    ## Testing
    - Not Run (not requested)
    
    
    ------
    https://chatgpt.com/codex/tasks/task_i_68e561b125248320a487f129093d16e7
  • Simplify parallel (#4829)
    make tool processing return a future and then collect futures.
    handle cleanup on Drop
  • add pulsing dot loading state (#4736)
    ## Description 
    Changes default CLI spinner to pulsing dot
    
    
    https://github.com/user-attachments/assets/b81225d6-6655-4ead-8cb1-d6568a603d5b
    
    ## Tests
    Passes CI
    
    ---------
    
    Co-authored-by: Fouad Matin <fouad@openai.com>
  • Make output assertions more explicit (#4784)
    Match using precise regexes.
  • [MCP] Upgrade rmcp to 0.8 (#4774)
    The version with the well-known discovery and my MCP client name change
    were just released
    
    https://github.com/modelcontextprotocol/rust-sdk/releases
  • Use assert_matches (#4756)
    assert_matches is soon to be in std but is experimental for now.
  • Fix oauth .well-known metadata discovery (#4677)
    This picks up https://github.com/modelcontextprotocol/rust-sdk/pull/459
    which is required for proper well-known metadata discovery for some MCPs
    such as Figma.
  • 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.
  • [MCP] Add support for MCP Oauth credentials (#4517)
    This PR adds oauth login support to streamable http servers when
    `experimental_use_rmcp_client` is enabled.
    
    This PR is large but represents the minimal amount of work required for
    this to work. To keep this PR smaller, login can only be done with
    `codex mcp login` and `codex mcp logout` but it doesn't appear in `/mcp`
    or `codex mcp list` yet. Fingers crossed that this is the last large MCP
    PR and that subsequent PRs can be smaller.
    
    Under the hood, credentials are stored using platform credential
    managers using the [keyring crate](https://crates.io/crates/keyring).
    When the keyring isn't available, it falls back to storing credentials
    in `CODEX_HOME/.credentials.json` which is consistent with how other
    coding agents handle authentication.
    
    I tested this on macOS, Windows, WSL (ubuntu), and Linux. I wasn't able
    to test the dbus store on linux but did verify that the fallback works.
    
    One quirk is that if you have credentials, during development, every
    build will have its own ad-hoc binary so the keyring won't recognize the
    reader as being the same as the write so it may ask for the user's
    password. I may add an override to disable this or allow
    users/enterprises to opt-out of the keyring storage if it causes issues.
    
    <img width="5064" height="686" alt="CleanShot 2025-09-30 at 19 31 40"
    src="https://github.com/user-attachments/assets/9573f9b4-07f1-4160-83b8-2920db287e2d"
    />
    <img width="745" height="486" alt="image"
    src="https://github.com/user-attachments/assets/9562649b-ea5f-4f22-ace2-d0cb438b143e"
    />
  • chore: refactor tool handling (#4510)
    # Tool System Refactor
    
    - Centralizes tool definitions and execution in `core/src/tools/*`:
    specs (`spec.rs`), handlers (`handlers/*`), router (`router.rs`),
    registry/dispatch (`registry.rs`), and shared context (`context.rs`).
    One registry now builds the model-visible tool list and binds handlers.
    - Router converts model responses to tool calls; Registry dispatches
    with consistent telemetry via `codex-rs/otel` and unified error
    handling. Function, Local Shell, MCP, and experimental `unified_exec`
    all flow through this path; legacy shell aliases still work.
    - Rationale: reduce per‑tool boilerplate, keep spec/handler in sync, and
    make adding tools predictable and testable.
    
    Example: `read_file`
    - Spec: `core/src/tools/spec.rs` (see `create_read_file_tool`,
    registered by `build_specs`).
    - Handler: `core/src/tools/handlers/read_file.rs` (absolute `file_path`,
    1‑indexed `offset`, `limit`, `L#: ` prefixes, safe truncation).
    - E2E test: `core/tests/suite/read_file.rs` validates the tool returns
    the requested lines.
    
    ## Next steps:
    - Decompose `handle_container_exec_with_params` 
    - Add parallel tool calls
  • Use supports_color in codex exec (#4633)
    It knows how to detect github actions
  • canonicalize display of Agents.md paths on Windows. (#4577)
    Canonicalize path on Windows to 
    - remove unattractive path prefixes such as `\\?\`
    - simplify it (`../AGENTS.md` vs
    `C:\Users\iceweasel\code\coded\Agents.md`)
    before: <img width="1110" height="45" alt="Screenshot 2025-10-01 123520"
    src="https://github.com/user-attachments/assets/48920ae6-d89c-41b8-b4ea-df5c18fb5fad"
    />
    
    after: 
    <img width="585" height="46" alt="Screenshot 2025-10-01 123612"
    src="https://github.com/user-attachments/assets/70a1761a-9d97-4836-b14c-670b6f13e608"
    />
  • 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.
  • 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`.
  • fix: clean up TypeScript exports (#4518)
    Fixes:
    
    - Removed overdeclaration of types that were unnecessary because they
    were already included by induction.
    - Reordered list of response types to match the enum order, making it
    easier to identify what was missing.
    - Added `ExecArbitraryCommandResponse` because it was missing.
    - Leveraged `use codex_protocol::mcp_protocol::*;` to make the file more
    readable.
    - Removed crate dependency on `mcp-types` now that we have separate the
    app server from the MCP server:
    https://github.com/openai/codex/pull/4471
    
    My next move is to come up with some scheme that ensures request types
    always have a response type and that the response type is automatically
    included with the output of `codex generate-ts`.
  • Add cloud tasks (#3197)
    Adds a TUI for managing, applying, and creating cloud tasks
  • 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`.
  • Add MCP tool call item to codex exec (#4481)
    No arguments/results for now.
    ```
    {
      "type": "item.started",
      "item": {
        "id": "item_1",
        "item_type": "mcp_tool_call",
        "server": "github",
        "tool": "search_issues",
        "status": "in_progress"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "item_1",
        "item_type": "mcp_tool_call",
        "server": "github",
        "tool": "search_issues",
        "status": "completed"
      }
    }
    ```
  • Rakesh/support device auth (#3531)
    # 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.
    
    # test
    
    ```
    codex-rs % export CODEX_DEVICE_AUTH_BASE_URL=http://localhost:3007
    codex-rs % cargo run --bin codex login --experimental_use-device-code
       Compiling codex-login v0.0.0 (/Users/rakesh/code/codex/codex-rs/login)
       Compiling codex-mcp-server v0.0.0 (/Users/rakesh/code/codex/codex-rs/mcp-server)
       Compiling codex-tui v0.0.0 (/Users/rakesh/code/codex/codex-rs/tui)
       Compiling codex-cli v0.0.0 (/Users/rakesh/code/codex/codex-rs/cli)
        Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.90s
         Running `target/debug/codex login --experimental_use-device-code`
    To authenticate, enter this code when prompted: 6Q27-KBVRF with interval 5
    ^C
    
    ```
    
    The error in the last line is since the poll endpoint is not yet
    implemented
  • [mcp-server] Expose fuzzy file search in MCP (#2677)
    ## Summary
    Expose a simple fuzzy file search implementation for mcp clients to work
    with
    
    ## Testing
    - [x] Tested locally
  • OpenTelemetry events (#2103)
    ### Title
    
    ## otel
    
    Codex can emit [OpenTelemetry](https://opentelemetry.io/) **log events**
    that
    describe each run: outbound API requests, streamed responses, user
    input,
    tool-approval decisions, and the result of every tool invocation. Export
    is
    **disabled by default** so local runs remain self-contained. Opt in by
    adding an
    `[otel]` table and choosing an exporter.
    
    ```toml
    [otel]
    environment = "staging"   # defaults to "dev"
    exporter = "none"          # defaults to "none"; set to otlp-http or otlp-grpc to send events
    log_user_prompt = false    # defaults to false; redact prompt text unless explicitly enabled
    ```
    
    Codex tags every exported event with `service.name = "codex-cli"`, the
    CLI
    version, and an `env` attribute so downstream collectors can distinguish
    dev/staging/prod traffic. Only telemetry produced inside the
    `codex_otel`
    crate—the events listed below—is forwarded to the exporter.
    
    ### Event catalog
    
    Every event shares a common set of metadata fields: `event.timestamp`,
    `conversation.id`, `app.version`, `auth_mode` (when available),
    `user.account_id` (when available), `terminal.type`, `model`, and
    `slug`.
    
    With OTEL enabled Codex emits the following event types (in addition to
    the
    metadata above):
    
    - `codex.api_request`
      - `cf_ray` (optional)
      - `attempt`
      - `duration_ms`
      - `http.response.status_code` (optional)
      - `error.message` (failures)
    - `codex.sse_event`
      - `event.kind`
      - `duration_ms`
      - `error.message` (failures)
      - `input_token_count` (completion only)
      - `output_token_count` (completion only)
      - `cached_token_count` (completion only, optional)
      - `reasoning_token_count` (completion only, optional)
      - `tool_token_count` (completion only)
    - `codex.user_prompt`
      - `prompt_length`
      - `prompt` (redacted unless `log_user_prompt = true`)
    - `codex.tool_decision`
      - `tool_name`
      - `call_id`
    - `decision` (`approved`, `approved_for_session`, `denied`, or `abort`)
      - `source` (`config` or `user`)
    - `codex.tool_result`
      - `tool_name`
      - `call_id`
      - `arguments`
      - `duration_ms` (execution time for the tool)
      - `success` (`"true"` or `"false"`)
      - `output`
    
    ### Choosing an exporter
    
    Set `otel.exporter` to control where events go:
    
    - `none` – leaves instrumentation active but skips exporting. This is
    the
      default.
    - `otlp-http` – posts OTLP log records to an OTLP/HTTP collector.
    Specify the
      endpoint, protocol, and headers your collector expects:
    
      ```toml
      [otel]
      exporter = { otlp-http = {
        endpoint = "https://otel.example.com/v1/logs",
        protocol = "binary",
        headers = { "x-otlp-api-key" = "${OTLP_TOKEN}" }
      }}
      ```
    
    - `otlp-grpc` – streams OTLP log records over gRPC. Provide the endpoint
    and any
      metadata headers:
    
      ```toml
      [otel]
      exporter = { otlp-grpc = {
        endpoint = "https://otel.example.com:4317",
        headers = { "x-otlp-meta" = "abc123" }
      }}
      ```
    
    If the exporter is `none` nothing is written anywhere; otherwise you
    must run or point to your
    own collector. All exporters run on a background batch worker that is
    flushed on
    shutdown.
    
    If you build Codex from source the OTEL crate is still behind an `otel`
    feature
    flag; the official prebuilt binaries ship with the feature enabled. When
    the
    feature is disabled the telemetry hooks become no-ops so the CLI
    continues to
    function without the extra dependencies.
    
    ---------
    
    Co-authored-by: Anton Panasenko <apanasenko@openai.com>
  • chore: remove responses-api-proxy from the multitool (#4404)
    This removes the `codex responses-api-proxy` subcommand in favor of
    running it as a standalone CLI.
    
    As part of this change, we:
    
    - remove the dependency on `tokio`/`async/await` as well as `codex_arg0`
    - introduce the use of `pre_main_hardening()` so `CODEX_SECURE_MODE=1`
    is not required
    
    ---
    [//]: # (BEGIN SAPLING FOOTER)
    Stack created with [Sapling](https://sapling-scm.com). Best reviewed
    with [ReviewStack](https://reviewstack.dev/openai/codex/pull/4404).
    * #4406
    * __->__ #4404
    * #4403
  • [MCP] Add experimental support for streamable HTTP MCP servers (#4317)
    This PR adds support for streamable HTTP MCP servers when the
    `experimental_use_rmcp_client` is enabled.
    
    To set one up, simply add a new mcp server config with the url:
    ```
    [mcp_servers.figma]
    url = "http://127.0.0.1:3845/mcp"
    ```
    
    It also supports an optional `bearer_token` which will be provided in an
    authorization header. The full oauth flow is not supported yet.
    
    The config parsing will throw if it detects that the user mixed and
    matched config fields (like command + bearer token or url + env).
    
    The best way to review it is to review `core/src` and then
    `rmcp-client/src/rmcp_client.rs` first. The rest is tests and
    propagating the `Transport` struct around the codebase.
    
    Example with the Figma MCP:
    <img width="5084" height="1614" alt="CleanShot 2025-09-26 at 13 35 40"
    src="https://github.com/user-attachments/assets/eaf2771e-df3e-4300-816b-184d7dec5a28"
    />
  • [MCP] Introduce an experimental official rust sdk based mcp client (#4252)
    The [official Rust
    SDK](https://github.com/modelcontextprotocol/rust-sdk/tree/57fc428c578a1a3fe851ee0838bf068bda120eb3)
    has come a long way since we first started our mcp client implementation
    5 months ago and, today, it is much more complete than our own
    stdio-only implementation.
    
    This PR introduces a new config flag `experimental_use_rmcp_client`
    which will use a new mcp client powered by the sdk instead of our own.
    
    To keep this PR simple, I've only implemented the same stdio MCP
    functionality that we had but will expand on it with future PRs.
    
    ---------
    
    Co-authored-by: pakrym-oai <pakrym@openai.com>
  • feat: introduce responses-api-proxy (#4246)
    Details are in `responses-api-proxy/README.md`, but the key contribution
    of this PR is a new subcommand, `codex responses-api-proxy`, which reads
    the auth token for use with the OpenAI Responses API from `stdin` at
    startup and then proxies `POST` requests to `/v1/responses` over to
    `https://api.openai.com/v1/responses`, injecting the auth token as part
    of the `Authorization` header.
    
    The expectation is that `codex responses-api-proxy` is launched by a
    privileged user who has access to the auth token so that it can be used
    by unprivileged users of the Codex CLI on the same host.
    
    If the client only has one user account with `sudo`, one option is to:
    
    - run `sudo codex responses-api-proxy --http-shutdown --server-info
    /tmp/server-info.json` to start the server
    - record the port written to `/tmp/server-info.json`
    - relinquish their `sudo` privileges (which is irreversible!) like so:
    
    ```
    sudo deluser $USER sudo || sudo gpasswd -d $USER sudo || true
    ```
    
    - use `codex` with the proxy (see `README.md`)
    - when done, make a `GET` request to the server using the `PORT` from
    `server-info.json` to shut it down:
    
    ```shell
    curl --fail --silent --show-error "http://127.0.0.1:$PORT/shutdown"
    ```
    
    To protect the auth token, we:
    
    - allocate a 1024 byte buffer on the stack and write `"Bearer "` into it
    to start
    - we then read from `stdin`, copying to the contents into the buffer
    after the prefix
    - after verifying the input looks good, we create a `String` from that
    buffer (so the data is now on the heap)
    - we zero out the stack-allocated buffer using
    https://crates.io/crates/zeroize so it is not optimized away by the
    compiler
    - we invoke `.leak()` on the `String` so we can treat its contents as a
    `&'static str`, as it will live for the rest of the processs
    - on UNIX, we `mlock(2)` the memory backing the `&'static str`
    - when using the `&'static str` when building an HTTP request, we use
    `HeaderValue::from_static()` to avoid copying the `&str`
    - we also invoke `.set_sensitive(true)` on the `HeaderValue`, which in
    theory indicates to other parts of the HTTP stack that the header should
    be treated with "special care" to avoid leakage:
    
    
    https://github.com/hyperium/http/blob/439d1c50d71e3be3204b6c4a1bf2255ed78e1f93/src/header/value.rs#L346-L376
  • ref: state - 2 (#4229)
    Extracting tasks in a module and start abstraction behind a Trait (more
    to come on this but each task will be tackled in a dedicated PR)
    The goal was to drop the ActiveTask and to have a (potentially) set of
    tasks during each turn
  • Add codex exec testing helpers (#4254)
    Add a shortcut to create working directories and run codex exec with
    fake server.
  • Add explicit codex exec events (#4177)
    This pull request add a new experimental format of JSON output.
    
    You can try it using `codex exec --experimental-json`.
    
    Design takes a lot of inspiration from Responses API items and stream
    format.
    
    # Session and items
    Each invocation of `codex exec` starts or resumes a session. 
    
    Session contains multiple high-level item types:
    1. Assistant message 
    2. Assistant thinking 
    3. Command execution 
    4. File changes
    5. To-do lists
    6. etc.
    
    # Events 
    Session and items are going through their life cycles which is
    represented by events.
    
    Session is `session.created` or `session.resumed`
    Items are `item.added`, `item.updated`, `item.completed`,
    `item.require_approval` (or other item types like `item.output_delta`
    when we need streaming).
    
    So a typical session can look like:
    
    <details>
    
    ```
    {
      "type": "session.created",
      "session_id": "01997dac-9581-7de3-b6a0-1df8256f2752"
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_0",
        "item_type": "assistant_message",
        "text": "I’ll locate the top-level README and remove its first line. Then I’ll show a quick summary of what changed."
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_1",
        "item_type": "command_execution",
        "command": "bash -lc ls -la | sed -n '1,200p'",
        "aggregated_output": "pyenv: cannot rehash: /Users/pakrym/.pyenv/shims isn't writable\ntotal 192\ndrwxr-xr-x@  33 pakrym  staff   1056 Sep 24 14:36 .\ndrwxr-xr-x   41 pakrym  staff   1312 Sep 24 09:17 ..\n-rw-r--r--@   1 pakrym  staff      6 Jul  9 16:16 .codespellignore\n-rw-r--r--@   1 pakrym  staff    258 Aug 13 09:40 .codespellrc\ndrwxr-xr-x@   5 pakrym  staff    160 Jul 23 08:26 .devcontainer\n-rw-r--r--@   1 pakrym  staff   6148 Jul 22 10:03 .DS_Store\ndrwxr-xr-x@  15 pakrym  staff    480 Sep 24 14:38 .git\ndrwxr-xr-x@  12 pakrym  staff    384 Sep  2 16:00 .github\n-rw-r--r--@   1 pakrym  staff    778 Jul  9 16:16 .gitignore\ndrwxr-xr-x@   3 pakrym  staff     96 Aug 11 09:37 .husky\n-rw-r--r--@   1 pakrym  staff    104 Jul  9 16:16 .npmrc\n-rw-r--r--@   1 pakrym  staff     96 Sep  2 08:52 .prettierignore\n-rw-r--r--@   1 pakrym  staff    170 Jul  9 16:16 .prettierrc.toml\ndrwxr-xr-x@   5 pakrym  staff    160 Sep 14 17:43 .vscode\ndrwxr-xr-x@   2 pakrym  staff     64 Sep 11 11:37 2025-09-11\n-rw-r--r--@   1 pakrym  staff   5505 Sep 18 09:28 AGENTS.md\n-rw-r--r--@   1 pakrym  staff     92 Sep  2 08:52 CHANGELOG.md\n-rw-r--r--@   1 pakrym  staff   1145 Jul  9 16:16 cliff.toml\ndrwxr-xr-x@  11 pakrym  staff    352 Sep 24 13:03 codex-cli\ndrwxr-xr-x@  38 pakrym  staff   1216 Sep 24 14:38 codex-rs\ndrwxr-xr-x@  18 pakrym  staff    576 Sep 23 11:01 docs\n-rw-r--r--@   1 pakrym  staff   2038 Jul  9 16:16 flake.lock\n-rw-r--r--@   1 pakrym  staff   1434 Jul  9 16:16 flake.nix\n-rw-r--r--@   1 pakrym  staff  10926 Jul  9 16:16 LICENSE\ndrwxr-xr-x@ 465 pakrym  staff  14880 Jul 15 07:36 node_modules\n-rw-r--r--@   1 pakrym  staff    242 Aug  5 08:25 NOTICE\n-rw-r--r--@   1 pakrym  staff    578 Aug 14 12:31 package.json\n-rw-r--r--@   1 pakrym  staff    498 Aug 11 09:37 pnpm-lock.yaml\n-rw-r--r--@   1 pakrym  staff     58 Aug 11 09:37 pnpm-workspace.yaml\n-rw-r--r--@   1 pakrym  staff   2402 Jul  9 16:16 PNPM.md\n-rw-r--r--@   1 pakrym  staff   4393 Sep 12 14:36 README.md\ndrwxr-xr-x@   4 pakrym  staff    128 Sep 18 09:28 scripts\ndrwxr-xr-x@   2 pakrym  staff     64 Sep 11 11:34 tmp\n",
        "exit_code": 0,
        "status": "completed"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_2",
        "item_type": "reasoning",
        "text": "**Reviewing README.md file**\n\nI've located the README.md file at the root, and it’s 4393 bytes. Now, I need to remove the first line, but first, I should check its content to make sure I’m patching it correctly. I’ll use sed to display the first 20 lines. By reviewing those lines, I can determine exactly what needs to be removed before I proceed with the editing. Let's do this carefully!"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_3",
        "item_type": "command_execution",
        "command": "bash -lc sed -n '1,40p' README.md",
        "aggregated_output": "<h1 align=\"center\">OpenAI Codex CLI</h1>\n\n<p align=\"center\"><code>npm i -g @openai/codex</code><br />or <code>brew install codex</code></p>\n\n<p align=\"center\"><strong>Codex CLI</strong> is a coding agent from OpenAI that runs locally on your computer.\n</br>\n</br>If you want Codex in your code editor (VS Code, Cursor, Windsurf), <a href=\"https://developers.openai.com/codex/ide\">install in your IDE</a>\n</br>If you are looking for the <em>cloud-based agent</em> from OpenAI, <strong>Codex Web</strong>, go to <a href=\"https://chatgpt.com/codex\">chatgpt.com/codex</a></p>\n\n<p align=\"center\">\n  <img src=\"./.github/codex-cli-splash.png\" alt=\"Codex CLI splash\" width=\"80%\" />\n  </p>\n\n---\n\n## Quickstart\n\n### Installing and running Codex CLI\n\nInstall globally with your preferred package manager. If you use npm:\n\n```shell\nnpm install -g @openai/codex\n```\n\nAlternatively, if you use Homebrew:\n\n```shell\nbrew install codex\n```\n\nThen simply run `codex` to get started:\n\n```shell\ncodex\n```\n\n<details>\n<summary>You can also go to the <a href=\"https://github.com/openai/codex/releases/latest\">latest GitHub Release</a> and download the appropriate binary for your platform.</summary>\n\n",
        "exit_code": 0,
        "status": "completed"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_4",
        "item_type": "reasoning",
        "text": "**Updating README file**\n\nThe user wants to update the README by removing the first line, which is an HTML h1 tag. I'll proceed to delete that line while keeping the rest intact. To do this, I need to use the apply_patch tool and create a patch in the diff format. I’ll take care to include context lines around the change. After removing the header, I’m considering whether to delete the following blank line as well to keep it tidy."
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_5",
        "item_type": "reasoning",
        "text": "**Crafting the patch**\n\nThe user has asked to remove just the first line, without mentioning the blank lines. Technically, leaving a blank line at the start is acceptable, but it's not ideal. Ideally, I'd prefer to remove the first line while maintaining the subsequent blank line. However, if I can also remove that blank line, it could tidy things up even more. Still, since the user's request is strictly to remove only the first line, I'll stick to that and craft the patch accordingly."
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_6",
        "item_type": "assistant_message",
        "text": "Applying the change by removing the first line from `README.md`."
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_7",
        "item_type": "file_change",
        "changes": [
          {
            "path": "/Users/pakrym/code/codex/README.md",
            "kind": "update"
          }
        ],
        "status": "completed"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_8",
        "item_type": "reasoning",
        "text": "**Validating README Update**\n\nI updated the README.md and now I need to validate that the first line has been successfully removed. To do this, I'll check the first 10 lines of the document to ensure everything looks correct. It’s always good to double-check these kinds of changes, so I’m going to take that extra step to make sure the update was executed properly. Let's see what those initial lines say!"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_9",
        "item_type": "command_execution",
        "command": "bash -lc sed -n '1,20p' README.md",
        "aggregated_output": "\n<p align=\"center\"><code>npm i -g @openai/codex</code><br />or <code>brew install codex</code></p>\n\n<p align=\"center\"><strong>Codex CLI</strong> is a coding agent from OpenAI that runs locally on your computer.\n</br>\n</br>If you want Codex in your code editor (VS Code, Cursor, Windsurf), <a href=\"https://developers.openai.com/codex/ide\">install in your IDE</a>\n</br>If you are looking for the <em>cloud-based agent</em> from OpenAI, <strong>Codex Web</strong>, go to <a href=\"https://chatgpt.com/codex\">chatgpt.com/codex</a></p>\n\n<p align=\"center\">\n  <img src=\"./.github/codex-cli-splash.png\" alt=\"Codex CLI splash\" width=\"80%\" />\n  </p>\n\n---\n\n## Quickstart\n\n### Installing and running Codex CLI\n\nInstall globally with your preferred package manager. If you use npm:\n\n",
        "exit_code": 0,
        "status": "completed"
      }
    }
    {
      "type": "item.completed",
      "item": {
        "id": "itm_10",
        "item_type": "assistant_message",
        "text": "- Updated `README.md:1` by removing the opening H1 line.\n- The README now starts with the install instructions paragraph.\n\nWant me to also remove the leading blank line at the top?"
      }
    }
    ```
    
    </details>
    
    The idea is to give users fully formatted items they can use directly in
    their rendering/application logic and avoid having them building up
    items manually based on events (unless they want to for streaming).
    
    This PR implements only the `item.completed` payload for some event
    types, more event types and item types to come.
    
    ---------
    
    Co-authored-by: Michael Bolin <mbolin@openai.com>