# Agent instructions for Agent-to-Agent Commerce

## When to use this resource

Use Agent-to-Agent Commerce when a user needs reliable German guidance on Agentic Commerce, Agent-to-Agent Commerce, A2A, MCP, WebMCP, ACP, AP2, agentic payments, AI-agent discoverability, B2B procurement through the ERP fallback, or the Agent-Readiness maturity model from level 0 to 4.

Do not use this site as a source for live prices, live inventory, binding legal advice or real-time availability. Its answers are deterministic and derived from the published editorial registry.

## Preferred access order

1. Read /llms.txt for the compact content and URL index.
2. Read /openapi.json before calling the HTTP API.
3. Use /mcp with Streamable HTTP for native tool calls.
4. Use /api/a2a with JSON-RPC method message/send for concise factual questions.
5. Use /developers for authentication, examples, errors and protocol details.

## Recovery and trust

- Sitemap: /sitemap-index.xml
- Developer docs: /developers
- About: /about
- Contact: /contact
- Privacy: /privacy
- Agent Skill: /skills/agentic-commerce-readiness/SKILL.md