Connect ChatGPT to thirds.ai
Give this prompt to your AI agent. The agent does the task for you.
Read https://thirds.ai/docs/mcp/chatgpt and help me connect ChatGPT to thirds.ai with an API key
Use ChatGPT to build templates and create PDFs or images through the thirds.ai MCP server. Create an API key on the API keys page first. Each successful PDF or static image costs one credit.
Install the server
ChatGPT Developer mode is available on Plus, Pro, Business, Enterprise, and Education plans on the web. Workspace admins can turn the control off.
- Open ChatGPT Settings and turn on Developer mode. OpenAI currently places this under Security and login. Some builds still show it under Apps & Connectors → Advanced settings.
- Open ChatGPT Plugins, or Apps & Connectors, and create a new connector.
- Use these values:
| Setting | Value |
|---|---|
| Name | thirds |
| Connector URL | https://thirds.ai/mcp |
| Authentication | Token or API key |
| Secret | YOUR_API_KEY |
Keep the /mcp path on the URL. Choose Token or API key authentication, not OAuth and not no authentication. Paste the thirds.ai API key. If the form asks for a header name, set Authorization to Bearer YOUR_API_KEY.
OpenAI's Developer mode guide and plugin connection steps own the current menu labels.
Check the connection
Create the connector and wait for ChatGPT to scan the tools. Start a new chat, choose Developer mode from the tools menu, and enable thirds. Ask ChatGPT to list the thirds.ai tools.
Write actions ask for confirmation. Read the main MCP guide before you approve paid work.
FAQ
Why does ChatGPT return 401?
The connector must send a bearer API key. Recreate it with Token or API key authentication and an active key. Do not put the key in the URL.
Why are the tools missing in a new chat?
Turn Developer mode on, then enable the thirds app from the tools menu in that conversation. Deep Research connectors only expose search tools. This setup needs Developer mode.
Does connecting spend credits?
No. Connecting and listing tools don't spend credits. AI template work and successful renders can. Ask your agent to show the action and the cost before it starts paid work.