GPT Actions
The capability for a Custom GPT to call external APIs via an OpenAPI schema and perform real tasks. Public actions require a privacy-policy URL.
What are GPT Actions?
GPT Actions are the capability that connects a Custom GPT to external system APIs so it can perform real tasks during a conversation. When you define an endpoint with an OpenAPI schema, the GPT can call that API based on the user's request and reflect the result in its answer. It is the evolution of the earlier ChatGPT plugins concept, absorbed into Custom GPTs.
What can they do?
- Fetch real-time data (stock, pricing, availability, etc.)
- Run external services (run a diagnosis, create a ticket, search, etc.)
- Extend a "GPT that only talks" into a "GPT that acts" by wiring up first-party systems
For example, connecting a free diagnostic endpoint as an action lets the GPT run a real diagnosis and return the result when a user enters a domain.
Things to watch
- Public actions require a valid privacy-policy URL.
- Endpoints that need authentication must configure an auth method (API Key, OAuth, etc.).
- Because these are external calls, secure design — input validation, authorization, rate limiting — is a prerequisite.
Why does it matter for GEO?
GPT Actions let a brand provide real functionality on ChatGPT's internal surface (a Custom GPT), beyond simple guidance, which lifts return visits and conversion. Measure the effect by action call success rate and the conversion that follows.
Related terms
Is your site visible in AI search?
See for free how ChatGPT, Perplexity, and Gemini describe your brand.
Start Free Diagnosis →