TrustLedger

Trust, backed by evidence.

TrustLedger checks whether a UK company is safe to do business with, from inside your AI assistant. It looks the company up in Companies House, screens the company, its directors and owners against the OFAC and UN sanctions lists, and checks its website. You get APPROVE, ESCALATE or REJECT, with the evidence behind every flag.

It runs on your machine: the names you screen never leave it.

Decision support, not legal advice. You stay responsible for your compliance decisions.

Install

Needs Python 3.11+ and a free Companies House API key. No Claude or other LLM API key is needed: your assistant is the LLM.

uvx kyb-tool-mcp update-lists      # one-off: build the local sanctions index

Claude Code

claude mcp add kyb-tool-mcp -e COMPANIES_HOUSE_API_KEY=your-key -- uvx kyb-tool-mcp

Claude Desktop / Cursor: add to claude_desktop_config.json or .cursor/mcp.json, then restart.

{
  "mcpServers": {
    "kyb-tool-mcp": {
      "command": "uvx",
      "args": ["kyb-tool-mcp"],
      "env": { "COMPANIES_HOUSE_API_KEY": "your-key" }
    }
  }
}

pip

pip install kyb-tool-mcp

Without the Companies House key, registry checks report not_configured. Sanctions and website checks still run.

Use it

Ask your assistant in plain English:

• "Run a KYB check on company 09876543, director Sarah Holloway, born June 1979." → decision, flags with evidence, analyst note
• "Is Viktor Bout, born 1967, on a sanctions list?" → match / needs review / cleared, with reasons
• "Does harbourline-logistics.co.uk look real?" → reachable, parked, domain age, industry fit

Also works from the terminal (kyb-tool-mcp review case.json) and from Python (from kyb_tool_mcp import review_case).

Benchmark

Measured on real public UK data the tool was never tuned on (992 sanctioned designations, 5,000 companies) plus 168 test cases.

Coming next (phase 2)

• One-click install for Claude Desktop (desktop extension)
• Add it as a connector by URL (hosted version)
• A web form: check a company in the browser, no install

More

Policy and flags · Data sources · Contributing · Security · Apache-2.0 (data licences)