opencodex

Use Claude, Gemini, Grok, GLM, DeepSeek, Kimi, Qwen, Ollama, or any other LLM with Codex — without waiting for OpenAI to add support.

opencodex is a lightweight local proxy that translates Codex's Responses API into whatever your provider speaks. Streaming, tool calls, reasoning tokens, images — everything works, in both directions.

It can also manage a ChatGPT account pool for Codex auth. Add multiple ChatGPT / Codex accounts, refresh their 5h / weekly / 30d quota in the dashboard, and let new sessions auto-route to the lowest-usage healthy account. Existing Codex threads stay pinned to the account that started them, so long SSH, tmux, or mobile-connected sessions do not jump accounts mid-conversation.

Codex CLI / App / SDK ──/v1/responses──▶ opencodex ──▶ Any provider
                                              │
              Anthropic · Google · xAI · Kimi · Ollama Cloud · Groq
              OpenRouter · Azure · DeepSeek · GLM · …and OpenAI itself

flowchart LR
  codex[Codex session<br/>CLI, App, SSH, mobile] --> proxy[opencodex]
  proxy --> existing{Existing thread?}
  existing -->|yes| pinned[Keep the same<br/>ChatGPT account]
  existing -->|new session| quota[Refresh quota<br/>5h, weekly, 30d]
  quota --> pick[Pick lowest-usage<br/>healthy account]
  pick --> upstream[ChatGPT / Codex backend]
  pinned --> upstream
  upstream --> outcomes[Quota / auth outcome]
  outcomes -->|429| cooldown[Cooldown + failover]
  outcomes -->|401 / 403| reauth[Mark reauth needed]
  cooldown --> quota

Supported platforms

Requires Node 18+. The Bun runtime is bundled automatically on npm install — no separate Bun install needed. All three platforms work natively (no WSL needed on Windows).

Quick start

# Install (bundles the Bun runtime automatically — only Node 18+ required)
npm install -g @bitkyc08/opencodex

# Interactive setup (writes config, injects into Codex, and offers autostart shim install)
ocx init

# Start the proxy
ocx start

# If you skipped it during init, install the on-demand autostart shim later
ocx codex-shim install

# Use Codex normally — it now routes through opencodex
codex "Write a hello world in Rust"

opencodex bundles the Bun runtime as a dependency and runs it via a Node launcher, so you do not need to install Bun yourself. If you see a "bundled Bun runtime is missing" error, the install skipped lifecycle scripts or optional dependencies. Reinstall without those flags:

npm install -g @bitkyc08/opencodex   # no --ignore-scripts, no --omit=optional

Add a provider

The fastest way to add a provider is through the web dashboard:

ocx gui

This opens the dashboard at http://localhost:10100. From there:

1. Click "Add Provider"
2. Pick from 40+ built-in providers — or enter a custom OpenAI-compatible endpoint
3. Paste your API key (or log in via OAuth for Anthropic, xAI, and Kimi)
4. Models are auto-discovered from the provider's /v1/models endpoint

Your new provider is ready to use immediately. No restart needed.

You can also add providers through ocx init (interactive CLI) or by editing ~/.opencodex/config.json directly.

Model routing

Target any configured provider and model using the provider/model syntax:

# Use Claude Opus through Anthropic
codex -m "anthropic/claude-opus-4-8" "Explain this stack trace"

# Use Gemini through Google
codex -m "google/gemini-3-pro" "Write unit tests for auth.ts"

# Use GLM through Ollama Cloud
codex -m "ollama-cloud/glm-5.2" "Write a SQL migration"

# Use a local model through Ollama
codex -m "ollama/llama3" "Refactor this function"

When you omit the provider/ prefix, opencodex routes to the default provider — or auto-matches based on the model name pattern (e.g., claude-* routes to Anthropic, gpt-* routes to OpenAI).

Routed models also appear in the Codex App model picker with per-model reasoning effort controls:

Current Codex builds can expose low, medium, high, xhigh, max, and ultra reasoning controls when a model advertises them. opencodex keeps xhigh and max distinct unless a provider config explicitly maps one to the other. ultra mirrors upstream Codex semantics: it selects maximum reasoning plus proactive multi-agent delegation in the client, and is converted to max before any request reaches a provider. Routed models advertise it only when a provider config opts in via reasoningEfforts.

GPT-5.6 Sol/Terra/Luna are seeded as rollout-ready catalog entries for the OpenAI API key and OpenRouter presets (gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna; OpenRouter uses openai/...). They remain preview-gated by upstream availability; opencodex only prepares the routing and catalog metadata for accounts and providers that can serve them.

ChatGPT account pool

Open Codex Auth in the dashboard to add pool accounts and choose which account should handle the next Codex session. opencodex keeps two separate behaviors:

• Existing sessions keep affinity. A thread id is bound to the selected account and reused on later turns, so a long request or a mobile/SSH-attached session keeps using the same account.
• New sessions can auto-route. When auto-switch is enabled, opencodex compares the hottest known quota window across 5h, weekly, and 30d usage, then picks a lower-usage eligible account for new sessions once the active account crosses the threshold.
• Quota lookup is built in. The dashboard can refresh all account quotas in one click, and the request log labels pool traffic with non-PII account ordinals.
• Failures fail closed. Token failures mark reauthentication instead of falling back to another credential silently; 429 quota responses put the account in cooldown and can fail over future work to another eligible pool account.

Highlights

• Use any LLM with Codex. 5 protocol adapters cover Anthropic Messages, Google Gemini, Azure, OpenAI Responses passthrough, and every OpenAI-compatible Chat Completions endpoint — that's 40+ providers out of the box.
• Use any LLM with Claude Code too. The same daemon serves the Anthropic Messages API (/v1/messages + count_tokens): ocx claude launches Claude Code fully wired, and routed models appear in its native /model picker via gateway model discovery (claude-ocx-<provider>--<model> aliases, Claude Code 2.1.129+). Configure slots and model maps on the dashboard's Claude page.
• Pool ChatGPT accounts safely. Keep existing Codex threads on one account while new sessions can auto-pick a lower-usage account from the pool, with quota refresh and non-PII request labels.
• Log in once, skip the API key. OAuth support for xAI, Anthropic, and Kimi means you can authenticate with your existing account. Tokens auto-refresh. Or forward your codex login, paste an API key, or use ${ENV_VAR} references — your call.
• Works everywhere Codex does. Injects into Codex CLI, TUI, App, and SDK automatically. Routed models show up in Codex's model picker just like native ones.
• History-safe injection. On local installs the proxy points Codex's own built-in openai provider at itself via a single openai_base_url line — new threads keep their native provider tag, so ongoing chat history is never remapped and an unclean shutdown can't hide it. (Threads re-tagged by older versions are migrated back once on the first start; remote/LAN binds use a dedicated provider entry instead, since they need an API-key header.)
• Delegate to the right model. Feature up to five routed or native models in Codex's subagent picker from the dashboard or config — route complex tasks to a reasoning model, fast tasks to a cheap one. On the v2 multi-agent surface (GPT-5.6 Sol/Terra) the proxy injects compact delegation guidance: a preferred sub-agent model and effort (injectionModel / injectionEffort), the featured-model roster with the effort ladder each supports, and the fork_turns rules that make cross-model spawn_agent calls actually stick.