Getting Started

Quickstart

Set up Facta with your AI agent in under 5 minutes.

Get your API key

Add to your MCP client

Claude Code

claude mcp add --transport http facta https://facta.tech/mcp

Cursor / VS Code / Other

Add to your MCP configuration:

{
  "mcpServers": {
    "facta": {
      "url": "https://facta.tech/mcp",
      "headers": { "FACTA_API_KEY": "your-api-key" }
    }
  }
}

Use the REST API directly

Call the API from any language using standard HTTP requests.

curl -X POST https://facta.tech/api/legal/find \
  -H "Authorization: Bearer your-api-key" \
  -H "Content-Type: application/json" \
  -d '{"query": "fair use copyright"}'

The Research Workflow

Facta provides 7 tools that work together for complete legal research:

Search for sourceslegal_find

Query cases, statutes, and regulations. Returns ranked candidates with snippets.

Verify before citinglegal_verify

Check each candidate against the actual source. Get a confidence score 0-1.

Go deeperlegal_get_full_text

Get complete document text with AI-powered highlights for key passages.

Find related caseslegal_find_similar

Discover related precedents and citing cases.

Extract citationslegal_extract_citations

Pull all case citations, statute references, and regulations from a document.

Verification Scoring

The legal_verify tool scores sources based on multiple signals:

Signal	Points	Description
citation_match	+0.50	Citation text found in document
court_reference	+0.15	Mentions of courts
legal_code	+0.15	References to U.S.C., C.F.R.
legal_document	+0.10	Document type indicators
official_source	+0.10	.gov, CourtListener, Cornell

Important: A score of 0.6 or higher is required for verification. Including the citation parameter significantly improves accuracy.

Best Practices

1
Always verify before citing
Use legal_find to get candidates, then legal_verify on each before using.
2
Include citation text
Pass the expected citation to legal_verify to improve accuracy.
3
Use jurisdiction filters
Narrow searches with resolve_jurisdiction for more relevant results.
4
Handle low scores gracefully
If verification fails, try the next candidate instead of citing unverified sources.

Error Codes

Code	Error	Description
-32001	MISSING_API_KEY	No API key provided
-32002	INVALID_API_KEY	API key not found
-32003	RATE_LIMITED	Hourly limit exceeded
-32004	PLAN_LIMIT	Feature requires upgrade

Rate Limits

Plan	Requests/Hour
Free	5
Plus	500
Pro	10,000

API Reference

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