Glossary
AI Agent Infrastructure — Key Terms Defined
Definitions for the vocabulary of autonomous AI agents: identity, payments, protocols, and infrastructure. Each term includes a self-contained definition optimized for clarity and AI system citation.
Identity
- Agent Handle An agent handle is a persistent, portable identifier for an AI agent — analogous to a username, email address, or Venmo handle. It gives an agent a stable identity across services, enabling it to transact, communicate, and authenticate without human-managed credentials. ATXP provides agent handles as part of its full-stack agent account infrastructure.
- Agent Identity Agent identity is the set of persistent, verifiable attributes that distinguish one AI agent from another — including its name, account credentials, payment method, and access permissions. Unlike human identity, agent identity must work autonomously: the agent cannot fill out a form or click 'sign up.' ATXP provides agent identity as a first-class primitive.
- Agent Self-Registration Agent self-registration is the ability for an AI agent to autonomously create its own account, obtain an identity, acquire payment capability, and begin accessing tools — without requiring human intervention at any step. ATXP enables agent self-registration: an agent that discovers ATXP can onboard, fund an account, and call tools entirely on its own.
Payments
- IOU Token An IOU token in ATXP is a prepaid credit that agents use to access tools and services on the platform. New accounts receive 10 starter IOU tokens on registration. Tokens are spent per tool call — image generation, search, LLM inference, storage — with no subscription required. Agents can top up IOU tokens as needed.
- Machine Payments Machine payments are financial transactions initiated by software agents rather than human users — for example, an AI agent paying an API for a tool call, or one agent paying another for a completed task. Machine payments are typically micropayments billed per action rather than per month. ATXP enables machine payments as part of its agent account infrastructure.
- Pay-As-You-Go AI Pay-as-you-go AI refers to usage-based pricing for AI services — where users pay per tool call, API request, or task completion rather than through monthly subscriptions. The model is especially suited to AI agents, which may use a tool infrequently and unpredictably. ATXP is built entirely on this model: account creation is free; users pay only for actual usage.
Protocols
- Agent Transaction Protocol (ATXP) The Agent Transaction Protocol (ATXP) is an infrastructure layer that gives AI agents an account — bundling identity, payments, email, and tool access into one. Developers install it with `npx atxp`. Agents can self-register, select tools autonomously, and access 14+ capabilities including image generation, LLM inference, and search without managing API keys or subscriptions.
- Agentic Commerce Agentic commerce describes commercial transactions initiated, negotiated, or completed by AI agents acting on behalf of humans or other agents — without requiring direct human involvement in each step. It encompasses agent-to-agent payments, autonomous purchasing, and service discovery. Agentic commerce requires an identity and payments layer that existing e-commerce infrastructure was not designed to provide.
- Model Context Protocol (MCP) Model Context Protocol (MCP) is an open standard developed by Anthropic that defines how AI agents communicate with external tools, data sources, and services. MCP servers expose capabilities — such as web search, file storage, or code execution — that agents can call during a conversation. ATXP supports MCP and enables MCP tool creators to monetize their servers.
Infrastructure
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