The terminal or the editor.
Claude Code, Codex, Gemini CLI, GitHub Copilot in VS Code and other MCP clients connect with the same address. One command, then you sign in to Fortnox in the browser.
The steps in brief, then you ask.
More AI - ChatGPT & Claude MCP
SEK 119 per company per month · 30 days free
Connected. Ask about your books.
| Lindholms Bygg AB · 2 invoices | SEK 46,250 |
| Café Norrsken · 1 invoice | SEK 8,900 |
| Sjöberg Design · 3 invoices | SEK 31,400 |
| Total | SEK 86,550 |
Example.
Before you start: after the Fortnox sign-in we show a page (in Swedish) where you can add more companies with Lägg till ett bolag till (Add another company), before you go back to the client.
- The service is bought and activated for the right company in the Fortnox App Market. Buying and activating are two separate steps.
- A system administrator of the company's Fortnox does the sign-in. Fortnox requires it.
- BankID, or whatever else you sign in to Fortnox with, is at hand.
- Pop-ups are allowed. The Fortnox sign-in often opens in a window of its own.
- Ten minutes in one go. The Fortnox sign-in must be finished within ten minutes, and you must be back in the client within ten minutes of the last step.
Claude Code
Run the command in the terminal. The sign-in opens in the browser the next time a tool is used — or run /mcp in Claude Code and choose more to sign in straight away.
Codex
Run the command, then sign in with codex mcp login more. Your browser opens the Fortnox sign-in; choose the company and whether the connector may only read or also write.
Codex in the terminal, the Codex extension in your editor and the ChatGPT desktop app share the same settings (~/.codex/config.toml), so you connect once per computer. Check with codex mcp list, or /mcp inside Codex. Start your first question with Use More: so Codex picks the right tool. If you use Codex in ChatGPT on the web, follow the ChatGPT guide instead, since the connector there follows your ChatGPT account.
Gemini CLI
Add the connector and start Gemini CLI in a folder you trust. Then type /mcp auth more inside Gemini to sign in. Your browser opens the Fortnox sign-in; choose the company and whether the connector may only read or also write. Start your question with Use More:.
Gemini CLI signs in to Google with an API key from Google AI Studio (aistudio.google.com/apikey). The free key has a daily limit on the number of questions; enabling billing in Google AI Studio raises it considerably. Gemini CLI only loads connectors in a folder you have chosen to trust — if /mcp auth more says the server cannot be found, start Gemini again in such a folder.
In the Gemini app at gemini.google.com, custom connectors are added under Settings → Connected Apps → Add a custom app. For now Google offers this only in the US, for personal accounts and in English. When the option is available to you, connect with the same address.
GitHub Copilot in VS Code
Run MCP: Add Server from the command palette, choose HTTP and enter the address — or add the server yourself in .vscode/mcp.json. Sign in to Fortnox when the editor asks.
{
"servers": {
"more": {
"type": "http",
"url": "https://accounting.amore.cloud/mcp"
}
}
}Other MCP clients
Add the address as a remote server with HTTP transport and OAuth. The client registers itself with us (dynamic client registration), so there is no key or secret to paste — and you should never put one in a configuration file.
https://accounting.amore.cloud/mcpThe sign-in always happens at Fortnox, with your own user. Tools that change something need the same approval as in the chat apps: you see exactly what will be sent, and nothing is sent until you say yes.