DATEV MCP server: connect AI agents to DATEV from the EU

DATEV eG is the Nuremberg-based cooperative whose software runs accounting, payroll and document management in most German tax firms. It offers online and desktop APIs through its developer portal, but it does not publish an MCP server.

The Klardaten DATEV MCP server fills that gap. It exposes more than 100 data resources from six DATEV modules as MCP tools over Streamable HTTP, with read access by default and optional, separately granted writes. You need a Klardaten account and a DATEV environment that the gateway can reach.

A typical workflow is pre-booking for a Steuerberater: the agent reads incoming invoices from another connector, matches suppliers against DATEV addressees, proposes accounts and tax keys, and writes an uncommitted Buchungsstapel. A bookkeeper reviews the batch in DATEV and posts it.

Agents can also answer questions across clients, such as which open items are older than 60 days, compare postings between fiscal years, summarise payroll figures for a monthly report, or find a document in DATEV DMS and quote the relevant passage with its source.

On inference.eu, add the DATEV connector to an agent and point it at the Klardaten endpoint https://api.klardaten.com/mcp. The server uses OAuth 2.1 with dynamic client registration, so you sign in with your Klardaten login and approve the permissions; there is no key to copy by hand.

The resulting token is stored encrypted in the EU and only reaches the agents you allow. By default, connections use one shared DATEV service user. Klardaten profiles let each person connect with their own DATEV user and existing rights instead.

DATEV data is personal and often confidential, so it helps to know the path. The agent calls the Klardaten server, which reads from your DATEV environment through DATEVconnect. That flow involves Klardaten as a German third-party provider, in the same way as any other Klardaten client.

On inference.eu, the model that reads the results runs in EU data centres, and your connection credentials are stored encrypted in the EU. Check your data processing agreements with Klardaten and DATEV before connecting production client data.

Start read-only. Only grant the write permissions you need, for example uncommitted booking batches but not master data changes. Because batches stay uncommitted, the final posting is always a human step in DATEV.

On inference.eu you can require a person to approve risky tool calls before they run, such as creating a batch or uploading a document. Combine this with Klardaten's audit log and DATEV user profiles, so every action is traceable to a person and limited to that person's rights.