The agentic commerce glossary.

Agent orchestration is the coordination of multiple AI agents or tool calls — sequencing, parallelizing, and managing dependencies between the steps of a multi-step task.

An agent wallet is a blockchain wallet controlled by or on behalf of an AI agent, used to hold and spend funds — typically USDC on Base — for x402 payments.

Agentic commerce is commerce conducted autonomously by AI agents — discovering, paying for, and using services without a human completing each transaction.

An AI agent is a system that uses a large language model to autonomously plan and execute multi-step tasks, usually by calling external tools and acting on the results.

An API endpoint is a specific URL where an API can be accessed to perform one operation, such as fetching data or triggering an action.

An API key is a unique secret token used to authenticate requests to an API, traditionally issued to a developer after manual signup.

An API marketplace is a platform where developers — and increasingly AI agents — discover, evaluate, and access third-party APIs and MCP servers, often with built-in billing.

An autonomous agent is an AI agent that operates with minimal human oversight, making its own decisions about which tools to use, when to act, and how to spend its budget.

Base is a low-cost Ethereum Layer 2 network incubated by Coinbase, used as the settlement chain for x402 USDC payments on Loomal.

On Loomal, an unclaimed listing is auto-indexed from public registry data; claiming it proves ownership and unlocks editing, richer metadata, and x402 monetization.

The context window is the maximum amount of text, measured in tokens, that an LLM can process at once — including prompts, conversation history, and tool results.

Ed25519 signed receipts are tamper-proof proofs of payment or access, produced with the Ed25519 elliptic-curve signature algorithm and verifiable by anyone holding the signer's public key.

An embedding is a numerical vector that represents text, images, or other data so that semantically similar items end up close together in vector space.

An x402 facilitator is a service that verifies and settles x402 payments on behalf of a resource server, so the server needs no blockchain infrastructure of its own.

Gas fees are the transaction fees a blockchain network charges to process and confirm a transaction, paid to the validators that execute it.

HTTP 402 Payment Required is the long-reserved HTTP status code signaling that a resource requires payment before access — the foundation the x402 protocol is built on.

JSON-RPC is a lightweight remote procedure call protocol encoded in JSON, and the wire format underlying all Model Context Protocol communication.

A large language model (LLM) is a neural network trained on vast text data that can understand and generate human-like language — and, increasingly, decide which tools to call.

An MCP client is the AI application — Claude Desktop, Cursor, VS Code, and others — that connects to MCP servers and calls their tools on a user's behalf.

An MCP manifest is a metadata file — typically server.json — that describes an MCP server's name, version, packages, and capabilities so registries can index it.

MCP monetization is the practice of adding a per-call payment gate to Model Context Protocol tool registrations so that AI agents pay before the tool handler runs.

An MCP registry is a catalog of published MCP servers — including the official registry maintained by the MCP project and community indexes built on top of it.

An MCP server is a program that exposes tools, resources, or prompts to AI applications using the Model Context Protocol.

MCPB (MCP Bundle) is a packaging format that distributes an MCP server as a single installable file, much like a browser extension package.

Micropayments are very small payments — often a cent or less — made for individual units of consumption, such as a single API call or document lookup.

The Model Context Protocol (MCP) is an open standard from Anthropic that lets AI applications connect to external tools, data sources, and APIs through one common interface.

OAuth is an open standard for delegated authorization that lets an application access a user's resources on another service without ever seeing the user's password.

The distinction between an MCP server you download and run yourself from source code, and one operated by its author as a managed remote endpoint you simply connect to.

A pay-per-call API is an API priced so that each individual request is billed separately — often via x402 — instead of through a subscription or pre-purchased credits.

Pay-per-use pricing is a model that charges based on actual consumption — per call, per token, per document — rather than a flat subscription fee.

A payment channel is an off-chain mechanism that lets two parties exchange many small payments while recording only the opening and closing balances on-chain.

Prompts in MCP are reusable, parameterized prompt templates that a server exposes to clients, packaging a recommended workflow with the right framing and arguments built in.

Retrieval-Augmented Generation (RAG) is a technique that retrieves relevant external information and feeds it into an LLM's context before the model generates a response.

Rate limiting restricts how many requests a client can make to an API within a given time period, protecting the service from overload and abuse.

Resources are the MCP primitive that lets servers expose readable data — files, database rows, API responses — identified by URIs and loadable into the model's context.

Roots are an MCP mechanism by which a client tells a server which directories or URIs it is allowed to operate within.

Sampling is an MCP feature that lets a server request an LLM completion from the connected client, enabling agentic behavior inside the server without its own model access.

An SDK is a collection of libraries, tools, code samples, and documentation that helps developers build against a specific platform or protocol.

A settlement layer is the underlying blockchain or network where a payment is finally and irreversibly recorded.

SSE transport is an earlier MCP remote transport that paired a long-lived Server-Sent Events stream for server-to-client messages with HTTP POST for client-to-server messages.

A stablecoin is a cryptocurrency designed to maintain a stable value relative to a reference asset, usually the US dollar.

Stdio transport is a local MCP transport where the client launches the server as a subprocess and exchanges messages over standard input and output.

Streamable HTTP transport is the current MCP transport for remote servers, using HTTP POST with optional server-sent event streaming over a single endpoint.

Tool calling is the mechanism by which an LLM selects and invokes an external function or MCP tool to complete a task.

Tool use is the general capability of a large language model to invoke external functions or APIs as part of generating a response.

USDC is a US dollar-pegged stablecoin issued by Circle, used as the default settlement currency for x402 payments.

A vector database is a database optimized for storing and searching high-dimensional embeddings, the backbone of semantic search and RAG.

A webhook is an HTTP callback that a server sends to a configured URL when a specific event occurs.

x402 is an open, HTTP-native payment protocol that lets any server charge any client per request using HTTP status code 402 (Payment Required).

The x402 protocol is an open payment standard that uses the HTTP 402 status code to let AI agents pay for API and MCP tool access automatically, settled in stablecoins.