clgpt

Run Claude Code with a ChatGPT subscription through an unofficial community OAuth adapter. bun run src/cli.ts starts a local Anthropic-compatible server, translates Claude Code requests to the ChatGPT Codex Responses API, and launches the stock claude CLI in an isolated config directory.

This project is not an OpenAI product and does not use an OpenAI API key.

Install

Requirements: Claude Code, an eligible ChatGPT subscription, and Bun. From npm (Bun is still required at runtime):

npm install --global @semanticist14/clgpt

Update npm installs with npm install --global @semanticist14/clgpt@latest.

Or use the GitHub installer:

curl -fsSL https://raw.githubusercontent.com/semanticist21/clgpt/main/install.sh | bash

If Bun is missing, install it yourself:

curl -fsSL https://bun.sh/install | bash

Reopen your terminal after installing Bun. npm installs the package, but clgpt still runs on Bun because the adapter uses Bun's server and process APIs; Node is not a runtime fallback yet.

First run

clgpt

The first run opens a browser for ChatGPT OAuth, then asks whether to bypass permission prompts, replace Claude's unavailable built-in web search with ChatGPT native search, enable Playwright browser control, and choose a model on each start. Tokens are stored in ~/.config/clgpt/auth.json with mode 600; the Codex CLI cache is not read or shared.

Useful commands:

clgpt login       # sign in again in the browser
clgpt logout      # remove the clgpt OAuth session
clgpt status      # show account and model catalog
clgpt setup       # change startup defaults
clgpt update      # update after a staged install check

clgpt --no-bypass, clgpt --no-browser, clgpt --no-web, and clgpt --no-select override a saved default for one run. CLGPT_MODELS can restrict the local allowlisted GPT catalog with comma-separated ids.

Web access

Claude's built-in WebSearch cannot work through an adapter: Anthropic executes it server-side. With the web integration enabled, clgpt's adapter maps that tool onto ChatGPT's native web_search instead, so the search executes upstream and real results come back through Claude's own WebSearch. Claude's built-in Fetch keeps working as-is: it fetches pages locally and only the summarizing model call rides the adapter. No MCP server, no API key. Existing installs keep this off until clgpt setup is run; use clgpt --no-web for one run.

Browser control

The optional Playwright MCP integration needs the Playwright browser extension, which you install yourself. It does not install extensions or silently grant browser access. The extension token can be stored without putting it in shell history:

pbpaste | clgpt token
clgpt token --clear

Use CLGPT_MCP_PACKAGE to pin or redirect the MCP package. --no-browser disables it for one session.

The default server package is pinned to @playwright/[email protected]; the browser extension is installed and updated separately by Chrome. If you save an extension token with clgpt token, it is kept in ~/.config/clgpt/prefs.json with mode 600 and is read only by the short-lived MCP wrapper.

Security and privacy

• OAuth credentials stay in ~/.config/clgpt/auth.json; never commit that file.
• bun run src/cli.ts sends OAuth requests to auth.openai.com and model/chat requests to chatgpt.com/backend-api/codex/responses.
• Claude Code runs locally; the adapter binds to loopback and requires a local bearer token.
• Browser control is opt-in and uses the browser tab you explicitly share.
• This is an unofficial adapter. ChatGPT OAuth access and automated usage may change or stop working; use it only where your account and applicable terms permit.

Updates

Updates are staged in a temporary checkout. Dependencies and a version smoke test must pass before the live install is swapped, so a failed update leaves the previous revision active. Local changes and non-fast-forward branches stop the update.

Development

bun install
bun test
bun run check
bash -n install.sh scripts/write-launcher.sh uninstall.sh

Run the mock upstream for local adapter tests:

bun run scripts/mock-upstream.ts
CLGPT_UPSTREAM=http://127.0.0.1:9099 bun run src/cli.ts -p "Reply with exactly OK"

License: MIT