Developers (MCP)
Connect any MCP client to Lejr at https://lejr.app/mcp, approve it in your browser, and choose Full, Standard or Read-only access.
Lejr exposes a remote MCP server (the Model Context Protocol), so an MCP-capable AI assistant can work on your books directly. The same operations the in-app assistant uses, available to an assistant you already use elsewhere.
The practical version: you can ask Claude, in Claude, about your accounts, and it can answer from your actual ledger rather than from what you tell it.
Connecting an assistant
- Add Lejr as a connector
In your AI client, add a custom connector with the URL
https://lejr.app/mcp(it's also shown, with a copy button, under Settings → Account → AI connections). Your browser opens Lejr to sign in and approve the connection; there's no key to copy or paste. - Choose the access level
On the approval screen, pick Full access, Standard (everyday accounting, but no voiding or disposing), or Read-only, in which case the external assistant can analyze your books thoroughly and cannot write to them under any circumstances.
- Span multiple businesses if you need to
Unlike the in-app assistant, which is fixed to one organization per session, a single MCP connection can cover several, which suits an accountant with a number of clients, or an owner running multiple companies.
Read-only is a real boundary
Write-gating on a connection is enforced by the scope the connection was granted, not by the client's good behaviour. A read-only connection has no write operations available to it at all.
This is what makes it reasonable to hand an external assistant broad analytical access. It can read everything and change nothing, and that guarantee doesn't depend on how the request was phrased.
What's supported today
Claude is supported across desktop, web, and mobile, and is the path tested most heavily. ChatGPT and Grok connect as custom connectors; ChatGPT needs a Plus, Pro or Team plan and Grok needs X Premium or SuperGrok, on their side. Gemini is coming soon and Copilot is not connected; describing either as available today would be wrong.
The web application is entirely functional without any AI connection. MCP is an addition for people who already work with an assistant, not a dependency.
Good to know
- Over MCP, confirming a write is your AI client's own tool-approval prompt, not a Lejr card. Lejr enforces the connection's access level, your role in each business, and any tool group you've set to Block, on the server, whatever the client does.
- Settings → Account → AI connections lists every connection. Disconnecting one there cuts off its access immediately.
- This is also the integration point for your own automations, not only for chat assistants.