Housecarl
Housecarl Arbiter
Open the app →
Docs

Use it from Claude (no code)

The quickest way to start is to add Arbiter to Claude and ask questions in plain language. It works on Claude's free plan. Once it is connected, it is also available in Claude on your phone.

Add the connector

Arbiter is a custom connector: a remote server that uses the Model Context Protocol (MCP), an open standard that lets AI assistants call outside software. Claude's free plan allows one custom connector, which is all you need. Add it on the web (claude.ai) or in Claude Desktop:

  1. Open Customize → Connectors (some versions read Settings → Connectors).
  2. Click the + beside Connectors — older builds show an Add custom connector button instead. Name it Housecarl Arbiter and paste the Server URL below. Leave Advanced settings alone: the OAuth client ID and secret there are for servers that need you to bring your own, and Arbiter does not.
  3. Click Add. The first time you use it, Claude opens a sign-in window — approve it and you're connected.
https://api.arbiter.housecarl.cloud/mcp/v1

The connector is tied to your Claude account, not to one device: add it on the web or in Claude Desktop and it's there the next time you sign in on iOS or Android. (Adding connectors from the mobile apps themselves is still in beta — web and Desktop are the reliable path.) No API key is needed here; sign-in is handled for you. Claude reaches Arbiter from Anthropic's cloud, not from your machine, so there is nothing to install locally.

Then just ask

In any conversation, tap + → Connectors and switch on Housecarl Arbiter. The first time Claude uses an Arbiter tool it asks your permission — allow it. Then talk to it normally:

"Use Arbiter to investigate whether remote work lowers team productivity. Find the strongest sources on each side, weigh them, and give me a judged verdict."

"Read https://en.wikipedia.org/wiki/Cold_fusion, pull out the claims and the evidence it cites, run it through Arbiter, and tell me where the verdict is shaky."

Each investigation lands in your console under Sessions, where you can walk the reasoning tree and read the scored verdict. Building your own tool instead? The REST / MCP API is covered in Connect your tool.