Housecarl
Housecarl Arbiter
Open the app →
Docs

Quick Start — Connect Arbiter in Two Minutes

Quick Start

Connect in 2 minutes (no code)

Arbiter connects to AI assistants through the Model Context Protocol (MCP), an open standard that lets an assistant call outside software. In Claude, you add Arbiter as a connector. There is nothing to install and no file to edit.

Claude Desktop / Claude.ai

  1. Open Customize → Connectors (some versions read Settings → Connectors). Claude Desktop uses the same screen as the web — remote connectors are not added under Settings → MCP, which covers local servers
  2. Click the + beside Connectors (older builds: Add custom connector), name it Housecarl Arbiter
  3. Enter the endpoint URL: https://api.arbiter.housecarl.cloud/mcp/v1
  4. Click Add — the first time you use it, Claude opens a sign-in window; approve it and you're connected
  5. After signing in, Arbiter's 57 tools appear in your tool list
  6. Try it: ask Claude to "investigate whether [any claim] using Arbiter"

What to try first

Ask your AI assistant:

"Use Arbiter to investigate whether Tesla's Q4 revenue claims are supported by the evidence. Use SEC filings and analyst reports as sources."

Arbiter will:

  • Create an investigation session
  • Weigh each source's credibility
  • Detect contradictions between sources
  • Return a scored verdict you can trace and audit

Developer integration

The rest of this page is for developers who work with configuration files, API keys and raw requests. None of it is needed to use Arbiter from Claude.

Google Antigravity (Gemini)

Antigravity connects via API key in the headers field (Antigravity does not yet support MCP OAuth for remote servers).

1. Get an API key — sign up at ui.arbiter.housecarl.cloud, then go to Connection in your console and copy your key.

2. Add to your config — edit ~/.gemini/config/mcp_config.json:

{
  "mcpServers": {
    "arbiter": {
      "serverUrl": "https://api.arbiter.housecarl.cloud/mcp/v1",
      "headers": {
        "x-api-key": "YOUR_API_KEY_HERE"
      }
    }
  }
}

Use serverUrl — not url or httpUrl (Antigravity requires this field for remote Streamable HTTP connections).

3. Verify — in Antigravity CLI, run /mcp or ask "What MCP tools are available?" Arbiter's 57 tools should appear. In Antigravity IDE, open the MCP server manager to confirm the connection.

4. Try it — ask Gemini to "use Arbiter to investigate whether [any claim]"

Other MCP clients

Any MCP client that supports Streamable HTTP can connect:

  • Endpoint: https://api.arbiter.housecarl.cloud/mcp/v1
  • Transport: Streamable HTTP (MCP 2025-06-18 spec), JSON-RPC 2.0
  • Auth: x-api-key header with your API key

Get an API key at ui.arbiter.housecarl.cloud/connection.

API key (direct REST)

For programmatic access without MCP:

curl -X POST https://api.arbiter.housecarl.cloud/api/v1/investigations/analyze \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY_HERE" \
  -d '{
    "research_question": "Do the cited sources support the claim?",
    "actors": [{"id": "src1", "name": "Source", "source_type": "Analyst", "base_reliability": 0.8}],
    "subjects": [{"id": "s1", "name": "Topic", "subject_type": "claim"}],
    "claims": [{"id": "c1", "actor_id": "src1", "subject_id": "s1", "predicate": "accuracy", "value": "true", "content": "The claim text", "valence": "Supports"}]
  }'

Resources