Sovereign Agent Logbook

Every AI agent needs a logbook. Yours should stay in Europe.

An open-source, tamper-evident logbook for AI agents. It records each action, tool call and human approval your agent logs in an append-only, hash-chained file on your own server. Each entry says who, what, why, approved by whom and with what outcome. It works with any model (Mistral, GPT-NL, Llama, Claude, GPT…) because it speaks the open Model Context Protocol.

v0.1 is a working skeleton, not a finished product. It logs, chains, masks secrets, verifies and exports, and every claim on this page has a test behind it. What it does not do yet is listed honestly in ROADMAP.md.

Why

The EU AI Act requires providers and deployers of high-risk AI systems to keep logs and keep a human able to intervene (Articles 12, 14 and 26(6)). Those duties were due on 2 August 2026, or 2 August 2027 for AI built into regulated products. That changed with the Digital Omnibus on AI (Regulation (EU) 2026/1744, in force 27 July 2026). It moved them to 2 December 2027 for most high-risk systems and 2 August 2028 for AI built into regulated products. The clock moved; it did not stop. Reporting serious incidents (Article 73) sits in a different chapter of the Act, outside that postponement; check its timing for your system. The logbook gives you a verified timeline of the agent's logged actions to report from.

Autonomous agents make those duties harder. One task is ten tool calls, and when something goes wrong nobody can reconstruct which call did what, on whose approval.

Most tools for this live inside a US cloud platform or are built for one model vendor. If you run a sovereign setup — an open-weight model on your own hardware — there is nothing small and neutral to drop in. This is that thing.

What you get

• A tamper-evident log. Each event carries the hash of the previous one. Change, insert, remove or reorder a line and logbook verify tells you exactly where. (How, in one file of about 80 lines)
• Any model, any host, or no cloud at all. Four MCP tools: log_event, verify_logbook, recent_events, export_logbook.
• Secrets masked before writing. Keys that look like passwords, tokens, API keys, IBANs or BSNs are replaced with ***masked*** before hashing.
• No outbound network, proven by a public test. The test blocks outbound socket connections in the Python runtime and still completes a full write, verify and export cycle. A second test asserts that the logbook core imports no HTTP client. (tests/test_no_network.py)
• Audit-ready export. JSON and CSV your DPO or auditor can read without this tool.
• An open format. SPEC.md is the log format, separate from the code, Apache-licensed, so other tools can write it too.
• A Skills pack that teaches any agent when to log, what to write and when to stop and ask a human. (skills/sovereign-agent-logbook/SKILL.md)

Five-minute install

pip install git+https://github.com/Delfen-com/sovereign-agent-logbook

Point your MCP-capable agent host at the server over stdio. For Claude Desktop / Claude Code, Cursor, Continue, or any host with an mcpServers block:

{
  "mcpServers": {
    "logbook": {
      "command": "sovereign-agent-logbook",
      "env": { "LOGBOOK_PATH": "/var/lib/logbook/agent.jsonl" }
    }
  }
}

Or run it as a service on your own box with Docker:

docker build -t sovereign-agent-logbook .
docker run -d --name logbook \
  -p 127.0.0.1:8765:8765 \
  -v logbook-data:/data \
  sovereign-agent-logbook
# MCP endpoint: http://127.0.0.1:8765/mcp   (put TLS in front for anything beyond localhost)

Then, at any time, as a human:

logbook --path /var/lib/logbook/agent.jsonl verify
logbook --path /var/lib/logbook/agent.jsonl export --format csv > audit.csv
logbook --path /var/lib/logbook/agent.jsonl tail --limit 10

What an event looks like

{"spec":"0.1","seq":42,"id":"…","ts":"2026-11-05T20:41:03.123456+00:00",
 "prev_hash":"9f2c…","hash":"3a1b…",
 "agent_id":"invoice-bot","model":"mistral-small-4",
 "action":"pay_invoice","arguments":{"amount":1250,"iban":"***masked***"},
 "reason":"Invoice 2026-118 matches PO 4471 and is under the auto-approval limit",
 "approval":"auto","approved_by":null,"approval_rule":"pay-under-2000-matched-po",
 "outcome":"success","result_summary":"Paid via bank API, ref 88213",
 "run_id":"task-7f3e","tags":["finance"]}

Field meanings are normative in SPEC.md.

Trust: no black box

Not tied to one platform

GitHub is where most developers look, so this is the working repository. An identical mirror on EU-hosted infrastructure is planned so that the code never depends on a single platform; the target is being chosen and will be recorded in ROADMAP.md. Until then, git clone gives you a complete copy — that is the point of git.

Hosted version

If you would rather not run a server, a hosted version on EU-only infrastructure (Hetzner, Germany / Scaleway, France) with retention policies, daily signed anchoring of the chain and a monthly audit export is planned. Terms as offered on delfen.ai/logbook: €29 per month excluding VAT, 30-day free trial, cancel any time; if the hosted version is not live by the end of a trial, the trial is cancelled rather than charged.

Licence

Apache License 2.0. Built in the Netherlands by Delfen. Contributions welcome — see CONTRIBUTING.md.