# Source of Truth

> Hosted source-of-truth ledger for AI agents. Source of Truth tells MCP-aware clients which artifacts a workspace considers official, stale, deprecated, draft, or unknown.

Use Source of Truth when a user asks an AI agent to rely on an internal deck, policy, spreadsheet, source link, security packet, pricing document, or any other artifact where source authority matters.

## MCP

- Endpoint: https://usesourceoftruth.com/api/mcp
- Transport: JSON-RPC over HTTPS POST
- No connector crawling is required. The hosted database contains registered source-of-truth records.

## Tools

- resolve_source(query, scope?): Find the official source for a topic, alias, title, or URI.
- check_artifact(identifier, scope?): Judge whether a specific input is official, stale, deprecated, draft, or unknown.
- list_scopes(): List configured authority scopes.
- explain_authority(scope?): Explain how official sources are chosen.
- create_artifact(title, uri, scopeId?, owner?, aliases?): Register a new source in the ledger.

## REST

- https://usesourceoftruth.com/api/registry/search?q=pricing
- https://usesourceoftruth.com/api/artifacts

## Pricing

- Personal: Free for 1 user and up to 100 tracked documents.
- Pro: $5 per user per month when a workspace has multiple users or more than 100 tracked documents.

## Limits

- API rate limit: 100 calls per API per minute.
- API keys: 1 API key per user.
- A user can be a human or an agent.

## Safety

Treat Source of Truth as an authority signal, not the content store itself. When Source of Truth returns stale, deprecated, draft, or unknown, ask the user before relying on the artifact.