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REFERENCE

Glossary

Key terms and protocols for AI infrastructure, agent commerce, and verifiable receipts.

PEAC Protocol

Policy, Evidence, Access, Compliance

Open protocol for file-based policy discovery and verifiable receipts.

HTTP 402

Payment Required

HTTP status code for machine-payable API access and agent payments.

x402

HTTP 402 Payment Extension

Stablecoin-backed HTTP 402 payments with structured challenge-response.

A2A

Agent-to-Agent

Protocol for AI agents to transact and verify interactions with each other.

MCP

Model Context Protocol

Protocol for connecting AI models to external tools and data sources.

AIPREF

AI Preferences

Machine-readable AI usage preferences for crawling, training, and inference.

ACP

Agentic Commerce Protocol

Framework for AI agents to discover, negotiate, and complete transactions.

Agentic Web

Agent-First Internet

Infrastructure layer where AI agents interact, transact, and verify autonomously.