# claudex: use Claude Code's interface with GPT/Codex models through CLIProxyAPI > Source: > Published: 2026-07-12 16:23:26+00:00 Inspired by [Theo's original post on X]. The basic idea: if you prefer Claude Code's agent harness and terminal UX to the Codex CLI, `claudex` lets you keep Claude Code's interface, tools, permissions, plugins, and workflow while using GPT/Codex models underneath. A local [CLIProxyAPI](https://github.com/router-for-me/CLIProxyAPI) server translates and routes Claude Code's requests to a model available through Codex OAuth. The important isolation rule is: `claude` continues to work normally with its existing account and configuration.`codex` continues to work normally with its existing configuration.- Only `claudex` uses the local proxy and the selected Codex model. ``` Set up a new `claudex` command on my machine. It must run the Claude Code CLI interface and tooling while using `gpt-5.6-sol` through my Codex OAuth account and a localhost-only CLIProxyAPI server. Requirements: 1. Inspect before changing anything - Locate `cli-proxy-api`, `claude`, and `codex` and report their versions. - Inspect `cli-proxy-api --help` and any installed example config or systemd unit. - Inspect my shell configuration for existing `claude`, `claudex`, or similar aliases/functions. - Preserve all existing Claude Code and Codex behavior. - Do not print existing OAuth tokens, API keys, or credential-file contents. 2. Install CLIProxyAPI if it is missing - Use the official CLIProxyAPI quick-start documentation for the detected operating system. Do not invent package names or download URLs. - macOS with Homebrew: `brew install cliproxyapi` Be aware that `brew services` expects its config at `$(brew --prefix)/etc/cliproxyapi.conf`. If this setup uses `~/.cli-proxy-api/config.yaml`, safely back up any existing Homebrew config and symlink that expected path to the user config before starting the service. - Arch Linux: `yay -S cli-proxy-api-bin` or `paru -S cli-proxy-api-bin` The package includes an example config and a systemd user service. - Other Linux distributions: use the official installer from `router-for-me/cliproxyapi-installer`. Download it to a temporary file, inspect it, then run it; do not blindly execute a remote script if the environment's security policy forbids that. - Windows: use the current binary from the official GitHub releases page. This particular `claudex` alias targets zsh on macOS/Linux/WSL; adapt it to a PowerShell function only if the user explicitly wants native Windows. - Building from source is a fallback only when packages/releases are unsuitable; use the repository's documented `go build -o cli-proxy-api ./cmd/server` command and verify the required Go version first. - After installation, run `cli-proxy-api --help` and record the installed version. Confirm that the build exposes Codex and Claude OAuth flags before continuing. - Do not start the background service until a valid config file exists. 3. Configure CLIProxyAPI - Use `~/.cli-proxy-api/config.yaml` unless the installed service requires another path. - Bind only to `127.0.0.1` on port `8317`. - Disable TLS for this localhost-only connection. - Disable remote management and its control panel. - Use `~/.cli-proxy-api` as the OAuth auth directory. - Generate a new cryptographically random local API key. Never use an example or predictable key. - Store the client copy in `~/.cli-proxy-api/client.key`, not directly in the shell alias. - Set the directory to mode `0700` and all config, key, and OAuth JSON files to mode `0600`. - Keep normal retry defaults and use round-robin routing with session affinity disabled. The effective server config should be equivalent to: host: "127.0.0.1" port: 8317 tls: enable: false cert: "" key: "" remote-management: allow-remote: false secret-key: "" disable-control-panel: true auth-dir: "~/.cli-proxy-api" api-keys: - "GENERATE_A_RANDOM_LOCAL_KEY" debug: false logging-to-file: false usage-statistics-enabled: false request-retry: 3 max-retry-credentials: 0 max-retry-interval: 30 routing: strategy: "round-robin" session-affinity: false ws-auth: true 4. Run it as a user service - Prefer the systemd user unit included by the installed CLIProxyAPI package. - If no unit exists, create a user unit whose ExecStart runs the discovered binary with `-config %h/.cli-proxy-api/config.yaml`, restarts on failure, and starts after the network is available. - Run `systemctl --user daemon-reload` and enable/start the service. - Verify it is active and listening only on `127.0.0.1:8317`. 5. Authenticate both upstream accounts - Run the installed binary's Codex OAuth flow with the explicit config path. Current CLIProxyAPI builds use: `cli-proxy-api -config ~/.cli-proxy-api/config.yaml -codex-login` - Let me complete the browser approval when prompted. - Run the Claude OAuth flow similarly: `cli-proxy-api -config ~/.cli-proxy-api/config.yaml -claude-login` - Let me complete that browser approval too. - After each login, set newly created OAuth JSON files to mode `0600`. - Confirm the service hot-loaded both credentials, restarting it only if necessary. 6. Add only the `claudex` alias - Add the following logical alias to the correct zsh startup file, adapting paths if my shell or home layout differs: alias claudex='ANTHROPIC_BASE_URL=http://127.0.0.1:8317 ANTHROPIC_AUTH_TOKEN="$(<"$HOME/.cli-proxy-api/client.key")" CLAUDE_CODE_SUBAGENT_MODEL=gpt-5.6-sol CLAUDE_CODE_ALWAYS_ENABLE_EFFORT=1 CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCY=3 ENABLE_TOOL_SEARCH=false claude --model gpt-5.6-sol' - Keep these environment variables invocation-scoped. Do not export them globally and do not add them to `~/.claude/settings.json`. - Preserve argument forwarding so commands such as `claudex --continue`, `claudex --resume`, and `claudex -p "..."` work. - Do not redefine or wrap the normal `claude` or `codex` commands. 7. Verify the complete setup - An unauthenticated request to `http://127.0.0.1:8317/v1/models` must be rejected. - An authenticated request using `client.key` must succeed. - Confirm the returned model catalog contains `gpt-5.6-sol` and Claude models. - If `gpt-5.6-sol` is unavailable, stop and tell me; do not silently choose another model. - Run `claudex --version` to confirm argument forwarding. - Run one minimal request: `claudex -p "Reply with exactly: claudex route works"`. - Require the exact successful response before declaring completion. - Open a clean shell and prove `ANTHROPIC_BASE_URL` and `ANTHROPIC_AUTH_TOKEN` are unset globally. - Prove normal `claude` and `codex` still resolve exactly as they did before. - Report the final service status and credential permissions without revealing any secrets. Security constraints: - Never expose the proxy beyond localhost. - Never commit, paste, log, or display the generated local key or OAuth credentials. - Do not weaken TLS verification, Claude Code permissions, or sandbox settings. - Do not overwrite whole config files when a narrow merge is possible. - Ask me only for browser OAuth approval or genuinely missing product choices; handle discoverable machine details yourself. ``` `ANTHROPIC_BASE_URL` sends this Claude Code invocation to the local Anthropic-compatible proxy.`ANTHROPIC_AUTH_TOKEN` authenticates to the local proxy using a protected file.`--model gpt-5.6-sol` selects the Codex-backed model for the main Claude Code session.`CLAUDE_CODE_SUBAGENT_MODEL` keeps Claude Code subagents on the same model.`CLAUDE_CODE_ALWAYS_ENABLE_EFFORT=1` enables effort controls for the custom model.`CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCY=3` caps concurrent tool calls.`ENABLE_TOOL_SEARCH=false` disables dynamic tool search on the non-Anthropic gateway. Because all variables are attached to the alias invocation, they do not change the normal `claude` or `codex` environment. ``` claudex claudex --continue claudex --resume claudex -p "Explain this repository" ``` Model availability depends on the authenticated Codex account and the CLIProxyAPI version. Do not rename or silently substitute the requested model if it is missing from `/v1/models` . CLIProxyAPI changes quickly, so check the linked quick-start page before copying a command. ``` brew install cliproxyapi ``` When managed by `brew services` , Homebrew reads `$(brew --prefix)/etc/cliproxyapi.conf` . The official docs show how to symlink that path to `~/.cli-proxy-api/config.yaml` if you want the same layout used in this guide. ``` yay -S cli-proxy-api-bin # or paru -S cli-proxy-api-bin ``` The AUR package includes `/usr/share/doc/cli-proxy-api-bin/config.example.yaml` and a systemd user unit. Create the config before enabling the service. The official quick start currently provides this installer: ``` curl -fsSL https://raw.githubusercontent.com/router-for-me/cliproxyapi-installer/refs/heads/master/cliproxyapi-installer | bash ``` For a safer agent workflow, download the installer to a temporary file, inspect it, and then execute it instead of piping it directly to a shell. Download the appropriate binary from the project's official GitHub releases. Native Windows needs a PowerShell equivalent of the zsh alias; WSL can follow the Linux/zsh flow. [CLIProxyAPI repository](https://github.com/router-for-me/CLIProxyAPI)[CLIProxyAPI official quick start and installation](https://help.router-for.me/introduction/quick-start)[CLIProxyAPI basic configuration](https://help.router-for.me/configuration/basic)[CLIProxyAPI example configuration](https://github.com/router-for-me/CLIProxyAPI/blob/main/config.example.yaml)[CLIProxyAPI Codex OAuth](https://help.router-for.me/configuration/provider/codex)[CLIProxyAPI Claude OAuth](https://help.router-for.me/configuration/provider/claude-code)[CLIProxyAPI Claude Code client configuration](https://help.router-for.me/agent-client/claude-code)[Claude Code environment variables](https://code.claude.com/docs/en/env-vars)[Claude Code authentication and credential precedence](https://code.claude.com/docs/en/team)[Claude Code model configuration](https://code.claude.com/docs/en/model-config)[Original](https://x.com/theo/status/2076114415368482854)`claudex` inspiration from Theo