MCP Receipts

MCP + PEAC Integration

The Model Context Protocol (MCP) is Anthropic’s open standard for connecting AI assistants to external tools and data sources. Originary extends MCP by generating a cryptographically signed receipt for each tool invocation.

This provides verifiable proof of which tools were called, when, by whom, and under what policy constraints - essential for compliance and auditing in production AI systems.

Quickstart

1. Install the MCP server: npm install @peac/mcp-server
2. Add it to your MCP host (Claude Desktop, Cursor, or custom agent)
3. Configure your policy file via PEAC_POLICY_FILE env var
4. Use the 5 built-in tools: verify-receipt, inspect-receipt, decode-receipt, issue-receipt, create-bundle
5. Pure tools work offline; privileged tools require an issuer key via PEAC_ISSUER_KEY

Code Example

// Claude Desktop configuration (claude_desktop_config.json)
{
  "mcpServers": {
    "peac": {
      "command": "npx",
      "args": ["@peac/mcp-server"],
      "env": {
        "PEAC_POLICY_FILE": "./peac.txt"
      }
    }
  }
}

// Tools available: verify-receipt, inspect-receipt,
// decode-receipt, issue-receipt, create-bundle

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