How to connect Joist to ChatGPT, Claude and any AI agent

Yes, ChatGPT, Claude and other AI agents can work in your Joist account. Joist has no public API and no official MCP server. Cotlet.dev connects your own signed-in Joist account to any AI agent, so you can ask in plain words and the AI writes estimates, sends invoices and keeps your client list up to date for you.

What you can ask

Write an estimate for Mike Torres: replace 40 ft of deck boards, $1,850 labor plus $640 materials.

Which invoices have been unpaid for more than 30 days? List client, amount and due date.

Invoice Sarah Lee for Tuesday's bathroom tile job, $2,300, due in 14 days.

Add a new client, Dave Patel, 555-0142, 18 Oak Street, and draft an estimate for a kitchen faucet swap.

Send a friendly payment reminder to every client with an invoice overdue since last Friday. Show me the drafts first.

Connect in 2 minutes

Get your API key at https://cotlet.dev/app and export it as COTLET_API_KEY.

Claude Code

claude mcp add --transport http cotlet https://cotlet.dev/mcp/v1 --header "Authorization: Bearer $COTLET_API_KEY"

ChatGPT

Settings → Apps → add connector URL https://cotlet.dev/mcp/v1, then sign in with Cotlet.dev. No API key needed.

Cursor

Copy .cursor/mcp.json from this repo into your project:

{
  "mcpServers": {
    "cotlet": {
      "url": "https://cotlet.dev/mcp/v1",
      "headers": {
        "Authorization": "Bearer ${COTLET_API_KEY}"
      }
    }
  }
}

Run it locally (stdio)

This repo is a real MCP server. It speaks MCP over stdio, lists its Joist tools without any key, and forwards every tool call to the hosted Cotlet.dev server. The hosted URL above stays the recommended way. Use this when your client only starts local servers.

{"mcpServers":{"joist":{"command":"uvx","args":["joist-mcp"],"env":{"COTLET_API_KEY":"your-key"}}}}

Or with Docker:

docker build -t joist-mcp .
docker run -i --rm -e COTLET_API_KEY joist-mcp

Tools: joist_guide, joist_status, joist_open, joist_read, joist_click, joist_type, joist_close. Without COTLET_API_KEY a tool call answers: "Set COTLET_API_KEY. Get a key at https://cotlet.dev/app".

Command line

Python 3.10+, nothing else to install. From PyPI:

pip install joist-mcp        # or run it once: uvx joist-mcp connect
joist-mcp connect

Or straight from this repo:

export COTLET_API_KEY="your-key"
python3 joist_agent.py connect   # ready config for Claude Code, Cursor, ChatGPT
python3 joist_agent.py status    # is Joist ready in your Cotlet.dev account
python3 joist_agent.py guide     # Joist screens and sign-in link
python3 joist_agent.py read      # open Joist, read the page, close the browser
python3 joist_agent.py tools     # list Cotlet.dev tools
python3 joist_agent.py serve     # start the stdio MCP server (same as no argument)

Questions from Joist users

Does Joist have an API for developers?

Joist has no public, documented API for developers. Cotlet.dev works in your own Joist account directly, so your AI agent can create estimates, send invoices and look up clients without one.

How do I connect Joist to ChatGPT?

There is no official Joist app in ChatGPT. Add Cotlet.dev as an app in ChatGPT (Settings → Apps, connector URL https://cotlet.dev/mcp/v1), sign in to Joist once in your Cotlet.dev Cloud Browser, and ask ChatGPT in plain words. No code and no Joist API key.

Is there a way to use Claude with Joist?

Yes. In Claude Code run the one-line claude mcp add command above; in the Claude app add https://cotlet.dev/mcp/v1 as a custom connector. Claude then works in your own Joist account.

Is there a Joist MCP server?

Joist has no official MCP server. Cotlet.dev is a hosted MCP server that works in your Joist account for you, with ChatGPT, Claude, Cursor, Codex and n8n.

Find it on

• Joist on Cotlet.dev
• PyPI package joist-mcp
• Odel
• mcpbeat
• Step-by-step guide (PDF) on Internet Archive

Also works with

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• All apps connected through Cotlet.dev

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More: https://cotlet.dev/integrations/joist-api-mcp-server?utm_source=github&utm_medium=readme&utm_campaign=joist

Start free: https://cotlet.dev/signup?app=joist&utm_source=github&utm_medium=readme&utm_campaign=joist