OpenCodex

OpenCodex is a local-first, community-driven build of the Codex CLI focused on open model provider support. It keeps the familiar terminal coding-agent workflow while adding provider integrations that can be used without changing a global Codex installation.

The first release feature is native NVIDIA NIM support. More providers and quality-of-life features will be added from real community requests.

Community

OpenCodex is meant to be practical and community-shaped. If something breaks, open an issue. If a provider, model, or workflow is missing, open a feature request. If the request is clear, useful, and backed by official docs where needed, it can be added.

Bring the details that make the work actionable:

• What you tried.
• What failed or what you want added.
• Provider/model docs when the request involves an external API.
• Exact model ids, endpoints, and error messages when available.

Highlights

• Local Codex CLI build that can run side-by-side with a global Codex install.
• Built-in nvidia-nim model provider.
• NVIDIA NIM model discovery through the /v1/models endpoint.
• NVIDIA NIM chat-completions support through /v1/chat/completions.
• Streaming assistant output for NIM chat models.
• Thinking/reasoning display when a NIM model streams reasoning_content.
• Provider-specific shell guidance to prefer fast workspace search tools such as rg, rg --files, and git ls-files.

Future provider and feature integrations will be driven through GitHub issues. Open a provider request when you want another model host or API surface added.

Quick Start

Build the local binary from the Rust workspace:

cd codex-rs
$env:CARGO_HOME="$(Resolve-Path ..)\.cargo-local"
$env:CARGO_TARGET_DIR="$(Resolve-Path .)\target-local"
cargo build -j 1 -p codex-cli

Run the local binary without touching your global Codex data:

$env:CODEX_HOME="$(Resolve-Path ..)\.codex-local"
$env:NVIDIA_API_KEY="nvapi-your-key"

& ".\target-local\debug\codex.exe" `
  -c 'model_provider="nvidia-nim"' `
  -c 'model="z-ai/glm-5.1"'

On macOS or Linux, use the same config values with your local binary path:

cd codex-rs
export CODEX_HOME="$(cd .. && pwd)/.codex-local"
export NVIDIA_API_KEY="nvapi-your-key"

./target-local/debug/codex \
  -c 'model_provider="nvidia-nim"' \
  -c 'model="z-ai/glm-5.1"'

model_provider must be nvidia-nim. The model id is the full NIM model slug, for example z-ai/glm-5.1.

NVIDIA NIM

OpenCodex uses NVIDIA NIM's OpenAI-compatible API shape:

• Model catalog: GET /v1/models
• Chat inference: POST /v1/chat/completions
• Authentication: Authorization: Bearer <NVIDIA_API_KEY>

Default hosted endpoint:

https://integrate.api.nvidia.com/v1

Override the endpoint for a self-hosted or private NIM deployment:

$env:CODEX_NVIDIA_NIM_BASE_URL="https://your-nim-host.example.com/v1"

Detailed setup and troubleshooting are in docs/nvidia-nim.md.

Release Status

This release is provider-focused. NVIDIA NIM is the first supported external provider. Additional providers, model controls, and provider-specific features will be added based on community requests and tested integrations.

See RELEASE_NOTES.md for the current release notes.

Request a Feature

Use GitHub issues for requests:

• Provider/model request: use the Provider or Model Request issue template.
• Bug report: include codex --version, platform, provider, model id, and the exact command you ran.
• Feature request: describe the workflow, expected behavior, and links to any official API documentation.

Useful details for provider requests:

• Provider name and official API docs.
• Base URL and authentication method.
• Whether the provider supports chat completions, responses, tools, streaming, and reasoning/thinking fields.
• Example model ids you want supported.

Development

Common local commands:

cd codex-rs
$env:CARGO_HOME="$(Resolve-Path ..)\.cargo-local"
$env:CARGO_TARGET_DIR="$(Resolve-Path .)\target-local"

cargo fmt --package codex-core --package codex-model-provider
cargo check -j 1 -p codex-core -p codex-model-provider
cargo test -j 1 -p codex-model-provider
cargo build -j 1 -p codex-cli

Use -j 1 on machines where parallel Rust builds exhaust memory or pagefile space.

License

This repository is licensed under the Apache-2.0 License. Codex is an open source project originally released by OpenAI; OpenCodex adds community provider integration work on top of that codebase.