core-agent-ide/codex-rs
K Bediako 337643b00a
Fix: Render MCP image outputs regardless of ordering (#9815)
## What?
- Render an MCP image output cell whenever a decodable image block
exists in `CallToolResult.content` (including text-before-image or
malformed image before valid image).

## Why?
- Tool results that include caption text before the image currently drop
the image output cell.
- A malformed image block can also suppress later valid image output.

## How?
- Iterate `content` and return the first successfully decoded image
instead of only checking the first block.
- Add unit tests that cover text-before-image ordering and
invalid-image-before-valid.

## Before
```rust
let image = match result {
    Ok(mcp_types::CallToolResult { content, .. }) => {
        if let Some(mcp_types::ContentBlock::ImageContent(image)) = content.first() {
            // decode image (fails -> None)
        } else {
            None
        }
    }
    _ => None,
}?;
```
## After
```rust
let image = result
    .as_ref()
    .ok()?
    .content
    .iter()
    .find_map(decode_mcp_image)?;
```

## Risk / Impact
- Low: only affects image cell creation for MCP tool results; no change
for non-image outputs.

## Tests
- [x] `just fmt`
- [x] `cargo test -p codex-tui`
- [x] Rerun after branch update (2026-01-27): `just fmt`, `cargo test -p
codex-tui`

Manual testing

# Manual testing: MCP image tool result rendering (Codex TUI)

# Build the rmcp stdio test server binary:
cd codex-rs
cargo build -p codex-rmcp-client --bin test_stdio_server

# Register the server as an MCP server (absolute path to the built binary):
codex mcp add mcpimg -- /Users/joshka/code/codex-pr-review/codex-rs/target/debug/test_stdio_server

# Then in Codex TUI, ask it to call:
- mcpimg.image_scenario({"scenario":"image_only"})
- mcpimg.image_scenario({"scenario":"text_then_image","caption":"Here is the image:"})
- mcpimg.image_scenario({"scenario":"invalid_base64_then_image"})
- mcpimg.image_scenario({"scenario":"invalid_image_bytes_then_image"})
- mcpimg.image_scenario({"scenario":"multiple_valid_images"})
- mcpimg.image_scenario({"scenario":"image_then_text","caption":"Here is the image:"})
- mcpimg.image_scenario({"scenario":"text_only","caption":"Here is the image:"})

# Expected:
# - You should see an extra history cell: "tool result (image output)" when the
#   tool result contains at least one decodable image block (even if earlier
#   blocks are text or invalid images).


Fixes #9814

---------

Co-authored-by: Josh McKinney <joshka@openai.com>
2026-01-27 21:14:08 +00:00
..
.cargo chore(ci): add cargo audit workflow and policy (#7108) 2025-11-24 12:20:55 -08:00
.config fix flaky test: approval_matrix_covers_all_modes (#7028) 2025-11-20 14:37:42 -08:00
.github/workflows chore(ci): add cargo audit workflow and policy (#7108) 2025-11-24 12:20:55 -08:00
ansi-escape feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
app-server remove sandbox globals. (#9797) 2026-01-27 11:04:23 -08:00
app-server-protocol fix: handle all web_search actions and in progress invocations (#9960) 2026-01-27 03:33:48 +00:00
app-server-test-client Chore: add cmd related info to exec approval request (#9659) 2026-01-21 23:58:53 -08:00
apply-patch feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
arg0 fix: harden arg0 helper PATH handling (#8766) 2026-01-09 12:35:54 -08:00
async-utils feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
backend-client backend-client: add get_config_requirements_file (#10001) 2026-01-27 16:59:53 +00:00
chatgpt [connectors] Support connectors part 1 - App server & MCP (#9667) 2026-01-22 16:48:43 -08:00
cli Fix resume --last with --json option (#9475) 2026-01-26 20:20:57 -08:00
cloud-tasks add codex cloud list (#9324) 2026-01-16 08:56:38 -08:00
cloud-tasks-client add codex cloud list (#9324) 2026-01-16 08:56:38 -08:00
codex-api fix: handle all web_search actions and in progress invocations (#9960) 2026-01-27 03:33:48 +00:00
codex-backend-openapi-models backend-client: add get_config_requirements_file (#10001) 2026-01-27 16:59:53 +00:00
codex-client Log headers in trace mode (#9214) 2026-01-14 18:38:12 +00:00
common feat(tui) /permissions flow (#9561) 2026-01-21 21:38:46 -08:00
core enable live web search for DangerFullAccess sandbox policy (#10008) 2026-01-27 20:09:05 +00:00
debug-client [app-server] feat: add filtering on thread list (#9897) 2026-01-26 21:54:19 +00:00
docs Add thread/unarchive to restore archived rollouts (#9843) 2026-01-26 11:24:36 -08:00
exec Fix resume --last with --json option (#9475) 2026-01-26 20:20:57 -08:00
exec-server remove sandbox globals. (#9797) 2026-01-27 11:04:23 -08:00
execpolicy Another round of improvements for config error messages (#9746) 2026-01-23 20:11:09 -08:00
execpolicy-legacy feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
feedback feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
file-search feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
keyring-store feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
linux-sandbox remove sandbox globals. (#9797) 2026-01-27 11:04:23 -08:00
lmstudio chore(deps): bump tracing from 0.1.43 to 0.1.44 in /codex-rs (#9880) 2026-01-26 15:48:45 -08:00
login feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
mcp-server feat: dynamic tools injection (#9539) 2026-01-26 10:06:44 +00:00
mcp-types feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
network-proxy chore: introduce *Args types for new() methods (#10009) 2026-01-27 19:15:38 +00:00
ollama ollama: default to Responses API for built-ins (#8798) 2026-01-13 09:51:41 -08:00
otel feat: add session source as otel metadata tag (#9720) 2026-01-22 18:46:14 -08:00
process-hardening feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
protocol remove sandbox globals. (#9797) 2026-01-27 11:04:23 -08:00
responses-api-proxy Revert "fix: libcc link" (#9841) 2026-01-25 06:58:56 +00:00
rmcp-client Fix: Render MCP image outputs regardless of ordering (#9815) 2026-01-27 21:14:08 +00:00
scripts chore: upgrade to Rust 1.92.0 (#8860) 2026-01-16 11:12:52 -08:00
stdio-to-uds feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
tui Fix: Render MCP image outputs regardless of ordering (#9815) 2026-01-27 21:14:08 +00:00
utils fix: Fix tilde expansion to avoid absolute-path escape (#9621) 2026-01-21 10:43:10 -08:00
windows-sandbox-rs fix: handle utf-8 in windows sandbox logs (#8647) 2026-01-26 15:11:27 -08:00
.gitignore [MCP] Prefix MCP tools names with mcp__ (#5309) 2025-10-19 20:41:55 -04:00
BUILD.bazel feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
Cargo.lock feat(network-proxy): add a SOCKS5 proxy with policy enforcement (#9803) 2026-01-27 10:09:39 -08:00
Cargo.toml chore(deps): bump tracing from 0.1.43 to 0.1.44 in /codex-rs (#9880) 2026-01-26 15:48:45 -08:00
clippy.toml fix: switch rate limit reset handling to timestamps (#5304) 2025-10-17 17:39:37 -07:00
code Send text parameter for non-gpt-5 models (#4195) 2025-09-24 22:00:06 +00:00
config.md Fix link to MCP Servers config section (#5301) 2025-10-17 14:58:27 -07:00
default.nix fix: drop stale filedescriptor output hash for nix (#7865) 2025-12-11 10:43:50 -08:00
deny.toml feat: introducing a network sandbox proxy (#8442) 2026-01-23 17:47:09 -08:00
README.md chore: update outdated docs (#8701) 2026-01-03 02:19:52 -08:00
rust-toolchain.toml chore: upgrade to Rust 1.92.0 (#8860) 2026-01-16 11:12:52 -08:00
rustfmt.toml Update cargo to 2024 edition (#842) 2025-05-07 08:37:48 -07:00

Codex CLI (Rust Implementation)

We provide Codex CLI as a standalone, native executable to ensure a zero-dependency install.

Installing Codex

Today, the easiest way to install Codex is via npm:

npm i -g @openai/codex
codex

You can also install via Homebrew (brew install --cask codex) or download a platform-specific release directly from our GitHub Releases.

Documentation quickstart

What's new in the Rust CLI

The Rust implementation is now the maintained Codex CLI and serves as the default experience. It includes a number of features that the legacy TypeScript CLI never supported.

Config

Codex supports a rich set of configuration options. Note that the Rust CLI uses config.toml instead of config.json. See docs/config.md for details.

Model Context Protocol Support

MCP client

Codex CLI functions as an MCP client that allows the Codex CLI and IDE extension to connect to MCP servers on startup. See the configuration documentation for details.

MCP server (experimental)

Codex can be launched as an MCP server by running codex mcp-server. This allows other MCP clients to use Codex as a tool for another agent.

Use the @modelcontextprotocol/inspector to try it out:

npx @modelcontextprotocol/inspector codex mcp-server

Use codex mcp to add/list/get/remove MCP server launchers defined in config.toml, and codex mcp-server to run the MCP server directly.

Notifications

You can enable notifications by configuring a script that is run whenever the agent finishes a turn. The notify documentation includes a detailed example that explains how to get desktop notifications via terminal-notifier on macOS. When Codex detects that it is running under WSL 2 inside Windows Terminal (WT_SESSION is set), the TUI automatically falls back to native Windows toast notifications so approval prompts and completed turns surface even though Windows Terminal does not implement OSC 9.

codex exec to run Codex programmatically/non-interactively

To run Codex non-interactively, run codex exec PROMPT (you can also pass the prompt via stdin) and Codex will work on your task until it decides that it is done and exits. Output is printed to the terminal directly. You can set the RUST_LOG environment variable to see more about what's going on.

Experimenting with the Codex Sandbox

To test to see what happens when a command is run under the sandbox provided by Codex, we provide the following subcommands in Codex CLI:

# macOS
codex sandbox macos [--full-auto] [--log-denials] [COMMAND]...

# Linux
codex sandbox linux [--full-auto] [COMMAND]...

# Windows
codex sandbox windows [--full-auto] [COMMAND]...

# Legacy aliases
codex debug seatbelt [--full-auto] [--log-denials] [COMMAND]...
codex debug landlock [--full-auto] [COMMAND]...

Selecting a sandbox policy via --sandbox

The Rust CLI exposes a dedicated --sandbox (-s) flag that lets you pick the sandbox policy without having to reach for the generic -c/--config option:

# Run Codex with the default, read-only sandbox
codex --sandbox read-only

# Allow the agent to write within the current workspace while still blocking network access
codex --sandbox workspace-write

# Danger! Disable sandboxing entirely (only do this if you are already running in a container or other isolated env)
codex --sandbox danger-full-access

The same setting can be persisted in ~/.codex/config.toml via the top-level sandbox_mode = "MODE" key, e.g. sandbox_mode = "workspace-write".

Code Organization

This folder is the root of a Cargo workspace. It contains quite a bit of experimental code, but here are the key crates:

  • core/ contains the business logic for Codex. Ultimately, we hope this to be a library crate that is generally useful for building other Rust/native applications that use Codex.
  • exec/ "headless" CLI for use in automation.
  • tui/ CLI that launches a fullscreen TUI built with Ratatui.
  • cli/ CLI multitool that provides the aforementioned CLIs via subcommands.