Install

Total time: under two minutes if you already have Python 3.10+. No build step, no compilation.

Step 1 — install the server

Pick whichever fits your workflow. uvx is the lightest-touch — it runs the latest release on demand and never installs anything globally:

uvx mcp-chainladder
# or, for a one-time install on your PATH:
pipx install mcp-chainladder
# or, into any virtualenv:
pip install mcp-chainladder

If uvx isn't installed, get it with brew install uv (macOS) or pip install uv (cross-platform).

Step 2 — wire it into your MCP client

Claude Desktop

Edit the config file at:

Add the chainladder entry:

{
  "mcpServers": {
    "chainladder": {
      "command": "uvx",
      "args": ["mcp-chainladder"]
    }
  }
}

Quit and relaunch Claude Desktop. The chain-ladder tools now appear under the 🔌 icon at the bottom-left of any conversation.

Cursor

Cursor uses the same config shape, at ~/.cursor/mcp.json on macOS. Add the same mcpServers block as above.

Cline (VS Code)

Open the Cline sidebar → click the ⚙ icon → MCP Servers → Edit. Paste the same JSON block and save.

Continue (VS Code / JetBrains)

Edit ~/.continue/config.json and add the same block inside a top-level mcpServers key.

Zed

Zed → Settings → search for "Context Servers" → add a new entry: name chainladder, command uvx, args ["mcp-chainladder"].

Step 3 — try a sample conversation

Ask Claude anything that needs chain-ladder math. Examples:

"Use the sample triangle and tell me the IBNR."

"I have a paid-loss triangle at ~/Desktop/motor.csv.
 Run the chain ladder and flag any diagnostic concerns."

"Check whether AY 3's link ratios are outliers.
 Show me what excluding them does to the IBNR."

"Project the textbook triangle out 6 more years using
 an exponential tail fit."   (Pro tier — see pro.html)

Activate Pro (optional)

After purchasing a license at chainladder.app/pro, you'll receive a .license file by email. Install it at:

mkdir -p ~/.chainladder
mv ~/Downloads/your-name.license ~/.chainladder/license

Restart Claude Desktop. Ask Claude "check my Chain Ladder Pro license status" — if you see "Pro license active for your-email", you're done.

Troubleshooting

"uvx: command not found"

Install uv: brew install uv (macOS) or pip install uv (anywhere). Or use the pipx install path above; both work.

Claude Desktop doesn't show the tools

Three things to check:

  1. Did you quit and relaunch Claude Desktop completely? Cmd+Q on macOS — not just close the window.
  2. Is the JSON valid? Run cat ~/Library/Application\ Support/Claude/claude_desktop_config.json | python3 -m json.tool and confirm it parses.
  3. Run the server manually: uvx mcp-chainladder < /dev/null — it should exit cleanly with code 0. If it errors, the error message tells you what's wrong (usually a Python-version mismatch).

"pro_license_required" even after installing the license

The license file lives at ~/.chainladder/license exactly — no extension, no rename. Inside is a JSON file with the signature your seller's keygen issued. Check that you copied the file (not a screenshot or its contents) and that file ~/.chainladder/license reports "ASCII text" or "JSON".

What's next