MCP servers · OpenAI · connector · GPT action
Connect ChatGPT to OpenAI
One line gives ChatGPT your OpenAI account as tools: 4 endpoints, generate image, create embedding, text to speech, called with your own connection. No key in the prompt, a receipt for every call, revoke ChatGPT's access alone any time.
Three steps
- Create a free 0n3 account and connect OpenAI. Paste a key or sign in; it lands in your vault, encrypted.
- Install 0n3 into ChatGPT. A custom connector in Developer mode, or an Action on a custom GPT from the OpenAPI spec.
- Ask ChatGPT: whoami. Then: "Create an image in OpenAI".
Custom connector (needs Developer mode)
- Settings → Connectors (or Apps) → Advanced → Developer mode on
- Create → name 0n3 · MCP server URL https://0n3.app/mcp · Authentication: OAuth
- Finish the sign-in with your 0n account
- Enable the connector in a chat and ask: "whoami"
ChatGPT connectors cannot send a static header, so 0n3 signs you in through its OAuth door (dynamic client registration is on).
The line above carries a placeholder; 0n3.app/install mints a real key named for ChatGPT and fills it in.
What ChatGPT can then do in OpenAI
Generate image · Generate images with DALL-E1
Create an image
POST /images/generationsCreate embedding · Create text embeddings1
Create an embedding
POST /embeddingsText to speech · Convert text to speech1
Text to speech
POST /audio/speechGenerate text · Generate text completions0
Generate text completions
More · Everything else this app exposes.1
Chat completion
POST /chat/completionsOpenAI in other AI clients
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