A Browser-Side Rosetta Stone for ChatGPT Session Tokens

What it does

This single-page browser tool ingests ChatGPT web session JSON and reformats it into one of seven output schemas used by third-party API relay services, including CPA, sub2api, Cockpit, 9router, Codex, AxonHub, and Codex-Manager. All parsing and conversion stay local—no tokens are uploaded or written to storage.

The interesting bit

The tool acts as a Rosetta Stone for a fragmented ecosystem of ChatGPT proxy front-ends, each expecting its own auth dialect. It synthesizes placeholder JWT claims when a real id_token is missing, and it extracts account metadata by decoding the access token’s JWT payload client-side. Keeping everything in the browser is the rare privacy-conscious choice for a tool that handles live session credentials.

Key highlights

• Accepts five input formats (ChatGPT Web session, 9router, Codex native, AxonHub, Codex-Manager) and produces seven output formats.
• Runs fully client-side: no network upload, no localStorage, no server backend.
• Targets ChatGPT Plus accounts; the README notes that Free tier tokens cannot call model APIs even after conversion.
• Backfills email, account ID, plan type, and expiration by reading the accessToken JWT claims.
• Handles missing refresh_token gracefully—writing empty strings or explicit placeholders—so target tools do not assume auto-refresh is available.

Caveats

• ChatGPT Web sessions lack a refresh_token, so accounts expire when the access_token dies; no auto-renewal is possible.
• Utility is narrowly tied to specific third-party relay tools; if you do not use CPA, sub2api, or their siblings, the value is limited.
• The README is explicit that this is a Plus-account utility; Free users gain no API access from the conversion.

Verdict

Handy if you manage ChatGPT Plus accounts across third-party relay platforms and need to bridge web sessions into their native auth formats. If you source API keys officially or avoid proxy front-ends entirely, you can safely ignore it.