Specification

This section hosts the normative documents for ACP. Use them alongside the JSON Schema files in the public repository when implementing clients, control planes, or settlement adapters.

• Core Protocol Specification – Field-by-field overview of Agent Identity, Payment Intent, and Settlement Proof schemas plus REST endpoints.
• Discovery & Capability Advertising – How to publish AgentCards with payment capabilities, pricing, and compliance metadata.
• Interoperability with ACP & MCP – Guidance for layering ACP with existing messaging and tool protocols.
• Settlement Lifecycle – State transitions, event semantics, webhook contracts, and reconciliation requirements.

All documents target schema version 2025.0. Refer to release notes in the repository for migration steps when newer revisions become available.