OpenAI Launches Sign in with ChatGPT, Extending Subscriptions to Third-Party Apps

At DevDay, OpenAI announced "Sign in with ChatGPT / Bring Your ChatGPT Subscription Anywhere": users can log into third-party apps with their ChatGPT account and call models using the quota included in their Plus/Pro plans, without buying or configuring separate API keys for each app.

Confirmed

• The feature was officially announced by OpenAI developer platform lead Thibault Sottiaux (thsottiaux), with 16+ partner products at launch, including Devin, OpenCode, Notion, Kilo, Lovable, Vercel, and Warp (list relayed by Charlie Marsh, gaganghotra and others).
• The login scheme supports token sharing, letting users set custom usage caps per app (details from dkundel).
• Sourcegraph founder sqs announced that Amp (ampcode.com) supports the login, so users can use Amp directly with their ChatGPT subscription and credits.
• The browser product Pi announced support for Sign in with ChatGPT, letting users access their OpenAI subscription and API quota inside Pi without reconfiguring keys.
• thsottiaux said the ChatGPT subscription is no longer just a chat subscription but "the" subscription, hinting it's becoming a super-subscription hub bundling many capabilities.

Why it matters

• A game-changer for developers (peteryang): no need to convince users to pay another API fee for the same capability (BorisMPower), reducing payment friction in third-party apps.
• aakashgupta notes that subscriptions of roughly 50 million paying users are starting to work like a "wallet"; Menlo Ventures data shows US consumers on average use multiple AI apps, and making subscription quota portable across apps fits that trend.
• danshipper called the move hugely important for app developers, saying he had long been advocating for this model.
• cneuralnetwork observed that users no longer need to buy APIs separately for each app—subscription benefits have officially extended from ChatGPT itself to the third-party ecosystem.

2026-09-30 ~ 2026-10-01 · 17 related posts

• [source] OpenAI lets users bring their ChatGPT subscription into third-party apps — danshipper · 2026-09-30
• OpenAI Subscription Will Work in External Apps That Use GPTs — HarperSCarroll · 2026-09-30
• [source] Sign in with ChatGPT lets apps use users' existing subscription tokens, a game changer — petergyang · 2026-09-30
• Your ChatGPT plan tokens now work in any product — no separate API needed — cneuralnetwork · 2026-09-30
• ChatGPT integrates with 16 partner apps including Devin, Lovable and Notion — gaganghotra_ · 2026-09-30
• ChatGPT subscription now works inside 60+ partner products including Devin, OpenCode and Lovable — TheMoonMidas · 2026-09-30
• Sign in with ChatGPT launches with token sharing and custom usage limits — dkundel · 2026-09-30
• Warp Terminal adds ChatGPT sign-in, letting subscribers use Codex quota in agent CLI — vikvang1 · 2026-09-30
• ChatGPT subscription now works in 16+ partner products including Devin and Notion — charliermarsh · 2026-09-30
• Pi partners with OpenAI to bring Sign in with ChatGPT to its users — steipete · 2026-09-30
• OpenAI exec: ChatGPT is no longer just a subscription, it's THE subscription — paw_lean · 2026-09-30
• Amp adds Sign in with ChatGPT, letting subscribers use Amp with existing credits — socialwithaayan · 2026-10-01
• ChatGPT Plus/Pro can now pay inside 16 third-party apps as subscriptions turn into wallets — aakashgupta · 2026-10-01
• 16 apps now let you sign in with your ChatGPT subscription, no API key needed — TawohAwa · 2026-10-01
• Altman marvels at DevDay builders spinning up whole startups in a day — sama · 2026-10-01
• [source] Altman: Sign In With ChatGPT and plugin extensions hold untapped potential — sama · 2026-10-01

1 near-duplicate retellings: BorisMPower