GPT Actions

Requires: A custom GPT you can edit · An OpenAPI (Swagger) schema for the target API · Auth details for the API (API key or OAuth client)

1. 1

   Open the GPT editor's Configure tab

   Edit your GPT, scroll to the bottom, and choose Create new action (Add action).

2. 2

   Provide the OpenAPI schema

   Paste the OpenAPI JSON/YAML or import it from a hosted URL. Each path becomes a callable operation the GPT can invoke.

   yamlCopy

   openapi: 3.1.0
   info:
     title: Weather API
     version: 1.0.0
   servers:
     - url: https://api.example.com
   paths:
     /weather:
       get:
         operationId: getWeather
         parameters:
           - name: city
             in: query
             required: true
             schema: { type: string }

3. 3

   Configure authentication

   Set Authentication to None, API Key (server-to-server), or OAuth (when the action acts on behalf of a user account).

4. 4

   Test the action

   Use the editor's test panel to confirm the GPT calls the endpoint and parses the response.

You wired a weather API as an action and want the GPT to use it.

What to expect: The GPT calls the getWeather endpoint with city=Kyoto, then returns a grounded, one-sentence summary from the real API response.

• Name the operationId in your prompt when the GPT hesitates about which action to call.