Use Not So Fast AI inside Claude, ChatGPT and Claude Code

Add Not So Fast AI once as a connector. Then type "use notsofastai for this" in a chat: the app sends the task to Not So Fast AI, which answers with the cheapest model that can do it and reports the model, cost and saving.

Connector address:

https://mcp.notsofastai.com/mcp

The app asks you to sign in with your Not So Fast AI username and password. The connector acts only as you, with the same rights as in the web app. It can run tasks and missions, show your savings and plan bundles. It cannot run commands or open files.

1. Add the connector

Claude (web, desktop and mobile)

Open Customize → Connectors and click Add custom connector.
Name: Not So Fast AI. URL: https://mcp.notsofastai.com/mcp.
If you see an OAuth client choice, pick Register automatically. Leave client ID and secret empty.
Click Add, then Connect, and sign in on the Not So Fast AI page.
In a chat, use the + button → Connectors to switch it on.

On Team and Enterprise plans an owner adds it under Organization settings → Connectors → Add → Custom. Each member then clicks Connect.

ChatGPT

Turn on developer mode: Settings → Apps & Connectors → Advanced settings → Developer mode.
Add the server: Settings → Apps & Connectors → Create, or chatgpt.com/plugins → + → Add custom MCP server, depending on your version.
Name: Not So Fast AI. URL: https://mcp.notsofastai.com/mcp. Authentication: OAuth.
Sign in on the Not So Fast AI page, then create the app. In a chat, add it from the + menu.

Menu names and plan limits change often. On some plans ChatGPT only allows read-only tools from custom servers.

Claude Code

claude mcp add --transport http notsofastai https://mcp.notsofastai.com/mcp

Then type /mcp in Claude Code, choose notsofastai and sign in in the browser window that opens.

2. Make it the default (optional)

Paste this into your personal instructions. In Claude: Settings → Instructions for Claude. In ChatGPT: Settings → Personalization → Custom instructions. In Claude Code: your CLAUDE.md.

When I say "use notsofastai", "use NSF" or "NSF first", call the nsf_run_task tool with the full task (and any material it needs as context) and base your answer on its result. Mention the model and the saving it reports. For big multi-part jobs, use nsf_mission instead.

What the connector can do

nsf_run_task: send one task. Returns the answer, model, tier, cost and saving.
nsf_mission: a bigger goal. NSF writes acceptance criteria, splits the work, checks each part and returns one answer.
nsf_savings: your requests, cost and saving so far.
nsf_plan_bundle: which AI subscriptions fit a monthly budget.

Members use their own connected licences, exactly as in the web app. To disconnect, remove the connector in the app's settings.