What Fortnox gives through its API
Control.dev connects to Fortnox with OAuth: you sign in to Fortnox from Control.dev, choose the company and approve the access. Fortnox grants each permission for both reading and writing, Control.dev sends only read requests, and Fortnox stays the book of record.
- Financial years, the chart of accounts and general ledger vouchers
- Cost centres and projects
- Sales and supplier invoices and their payments
What an AI client gets from Fortnox alone today
Fortnox’s integration catalogue lists MCP connectors from other companies. Junipeer MCP för AI lets an AI assistant read and work with Fortnox data, with read or write access chosen per API key1. Sidcom’s AI Connector: Unlimited connects an AI client to every Fortnox company a user works in, each signed in with the user’s own Fortnox permissions2.
Klartext ChatGPT & Claude MCP from Göta IT reads only by default, and with read and write it also creates and changes data at the user’s request3. More AI from Starberg & More Solutions books, invoices and approves after showing each change account by account, and its entry names the group with internal items netted out4.
What Control.dev’s MCP adds above Fortnox
Control.dev reads Fortnox and the group’s other ledgers, Spiris (formerly Visma eEkonomi) among them, consolidates them and gives the whole group to the same AI client over MCP.
- Every entity on one group chart Each entity’s accounts are mapped to one group chart of accounts, and the eliminations, currency translation and CTA are done before the client reads. The eliminations sit in a column of their own.
- Statements first, not a raw export The client starts from the statements and the group structure, not a raw export of the general ledger. It finds what needs attention there and traces it to the entries.
- Every figure opens to its entries Every actual opens to the transactions behind it, and every row stays connected to its source system and legal entity.
- Your role decides what it sees Over MCP the client gets at most the access your role allows in Control.dev, and a read-only session rejects write tools.
- A plan with a reason on every cell The client can also draft budget values over MCP, and every value it writes carries its reason. The budget version keeps its change history, so a later variance analysis compares the actuals with the assumptions.
- Other MCP servers in the same conversation The client can use its other MCP servers in the same conversation, a CRM for example, and bring that data into a plan or an analysis next to the group’s actuals.
How each AI client connects is on the Control.dev MCP server, every tool it exposes on MCP tools and reusable instructions on finance skills, every integration and what comes in from it on the integrations page, and how the group view is built on multi-entity consolidation.
Already connected Claude to Fortnox yourself? Control.dev vs building it yourself with Claude compares what you build and keep alive, what the client reads, who may change what, and what it costs.
Fortnox MCP in three steps
Our team sets up the integration with you. Most companies have live data in under two hours from the first call, a larger group takes days, the hardest a few weeks, and there is no setup fee.
- 01Connect Fortnox with OAuth In Control.dev, add Fortnox as a data source, sign in to Fortnox, choose the company and approve the access. Each Fortnox company connects on its own. The steps and the permissions are in the Fortnox integration guide.
- 02Copy the server URL and the client ID into your client In Control.dev, open Data outputs and then MCP Server. Add the server URL and the client ID from the MCP Server page to Claude, ChatGPT or Codex as a remote MCP server, then sign in with your Control.dev login. If the page shows no client ID yet, ask us: registering your client is part of setup.
- 03Ask something you already know One company, one month, one figure. Check it against the same view in Control.dev, then ask the bigger questions.
Questions
How many integrations does a Fortnox group need, and what does it cost?
One per Fortnox company: one integration is one connected accounting system, such as one entity’s ledger. Control.dev publishes its monthly prices, excluding VAT: EUR 249 for one entity and one integration, EUR 499 for consolidation with three integrations and EUR 999 with five, where a Stripe connection counts as one integration, with no implementation fee, no multi-year contract and a notice period from one month. Larger groups are priced on request: book a demo.
Does Control.dev write to Fortnox?
No. Control.dev sends only read requests to Fortnox, so nothing it does changes Fortnox. Eliminations and group entries stay in Control.dev.
Where does the AI process our data?
Control.dev’s own AI features process data in the EU, and Control.dev’s data is hosted on Google Cloud in Hamina, Finland, encrypted in transit and at rest. What your AI client reads is processed under your agreement with its provider, so where that data goes is your decision.
How fast does a correction in Fortnox reach the group view?
Scheduled syncs run at least daily, and you can trigger a refresh on demand. Backdated entries and corrections are synced again automatically, so the next sync carries a correction into the group view and into what the client reads.
What do the Fortnox MCP connectors do, and when do you use both?
They connect an AI client to Fortnox companies, some across every company a user works in2, and some create and change data when you allow it3. Use one for work inside Fortnox. Use Control.dev for the group: entities on Fortnox and on other ledgers on one group chart of accounts, with the eliminations done. One AI client can use both servers in the same conversation.