OpenAI Expands "Sign in with ChatGPT" to Share Plan Allowances Across 16 Third-Party Tools
Summary
Updated Sep 30 — Official docs reveal Airtable, GitLab, HubSpot, and Supabase as added Sign in with ChatGPT partners, plus a ChatGPT Ads integration via HubSpot.
- • OpenAI extends Sign in with ChatGPT beyond identity to share Plus and Pro plan allowances
- • Subscribers can now use ChatGPT usage allowance inside 16 third-party tools including Devin and Notion
- • Altman: subscribers are already paying, removing token-cost barrier for new tool adoption
- • Feature was identity-only (OAuth-like) in July beta; plan usage sharing is new at DevDay 2026
Updates
Devin Cloud billing: ChatGPT plan covers OpenAI model share per session
When a ChatGPT Plus/Pro account is connected, the plan pays for the OpenAI-model portion of Devin Cloud sessions across all modes (Lite, Normal, Ultra, Fusion); other models draw from the user's included Devin quota. Devin also adjusts its model mix to lean more on OpenAI models when a plan is connected.
GPT-6 Sol available in Devin Cloud as a research preview for connected plan users
Devin is offering early access to GPT-6 Sol in Devin Cloud as a research preview for users who sign in with their ChatGPT Plus or Pro plan.
Fusion + GPT-6 Astra and SWE-2 sidekick is 39% cheaper than running Astra alone
In Fusion mode, GPT-6 Astra leads planning and review while the free sidekick SWE-2 handles most implementation work, cutting token spend by 39% per task vs. running Astra solo, per the Artificial Analysis Coding Agent Index.
ChatGPT Sign-In available on Devin Pro, Max, and Teams plans across all interfaces
The feature works in Devin Cloud, Desktop, and CLI. In Desktop and CLI, users select the model manually; all requests are then billed to the connected ChatGPT plan.
Official docs add Airtable, GitLab, HubSpot, Supabase as identity sign-in partners
OpenAI's official help documentation lists Airtable, GitLab, HubSpot, Notion, Supabase, and Vercel as initial participating partners, expanding the known set to include CRM and DevOps tools not named in the DevDay announcement.
ChatGPT Ads integration available through HubSpot connection
HubSpot can separately request access to a user's ChatGPT Ads account via Sign in with ChatGPT, linking OpenAI's advertising product to HubSpot's CRM and marketing platform.
Identity sign-in and subscription sharing are fully decoupled
Users can complete identity sign-in without approving subscription sharing. Subscription sharing does not grant partner apps access to ChatGPT conversations, memory, files, or billing information.
OpenAI Academy and ChatGPT Sites confirmed as Sign in with ChatGPT partners
Official docs confirm Sign in with ChatGPT is available on OpenAI Academy and ChatGPT Sites, extending beyond third-party developer tools to OpenAI's own educational and publishing platforms.
Details
Sign in with ChatGPT expands to plan usage sharing at DevDay 2026
Previously identity-only (OAuth-like), the feature now lets Plus and Pro subscribers apply their existing plan allowance to eligible usage inside participating third-party tools, with per-partner consumption controls.
Altman: plan portability lowers adoption barrier for third-party AI tools
Sam Altman told DevDay attendees: 'They're already paying for an AI subscription, and now you don't have to cover their token costs to get them going.' Partners reduce per-user acquisition friction.
July 2026 beta was identity-only; plan usage portability is entirely new today
In July, Sign in with ChatGPT allowed users to log into partner sites with their ChatGPT identity (name, email, profile picture). Additional plugin permissions required separate approval. Plan allowance sharing is the new capability added at DevDay.
16 launch partners span coding, productivity, and infrastructure categories
Currently available: OpenCode, OpenClaw, Pi, T3, Hyperagent, Hermes Agent, Vorflux, Amp, Dactyl, Kilo Code, Warp, Conductor, Devin, Notion, and Vercel. Lovable listed as 'coming soon.' OpenAI says more will be added quickly.
Eligible partner usage counts against ChatGPT plan limits; no API key required
Partners receive controls for how much of a user's allowance their tool can consume. Users authenticate through their normal ChatGPT account — no separate OpenAI API key required by the end user.
Dactyl previewed ChatGPT plan sharing since late August 2026 — a month before DevDay
Ryan Dahl's mobile vibe-coding platform Dactyl began offering ChatGPT plan integration in August. It uses the ChatGPT allowance to run the agent that writes Swift code for native mobile apps; compiling and publishing still consume Dactyl's own credits.
Announced at OpenAI DevDay 2026 alongside Dots agents and GPT-6.1 Sol model
Sign in with ChatGPT plan usage was one of several announcements at the fourth annual OpenAI DevDay developer conference, where OpenAI also unveiled always-on Dots agents and the GPT-6.1 Sol coding model.
Sources: The New Stack / TechMeme, September 2026.
What This Means
OpenAI is transforming its subscription into a platform asset: by letting Plus and Pro users spend their existing allowance in third-party tools, it creates strong incentives for developers to build on ChatGPT rather than competing API providers. This mirrors ecosystem lock-in strategies pioneered by Apple and Google — your existing payment relationship travels with you across a growing app marketplace. For third-party developers, the benefit is lower friction to acquiring paying users; for OpenAI, it deepens the moat by making the monthly ChatGPT subscription the default AI credential across an expanding partner ecosystem. The 16-partner launch concentrates on agentic coding tools, positioning ChatGPT plan sharing as a developer-first land-grab that could reshape how AI products are distributed and monetized.