# The Agent Economy > A public directory of the infrastructure agents use to talk, pay, trade, and take instruction. The directory lists mechanisms. It does not rank them. A figure without a public source stays UNKNOWN. Listings are alphabetical inside each category. Sponsor slots are labeled and do not change that order. Run by Max Curnin, Executive Chairman of Accords. Accords is listed under the same criteria as every other entry and is never ranked or styled differently. The Agent Economy listings (https://theagenteconomy.si/data/listings.json), licensed under CC BY 4.0. License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ## Listings - [A2A](https://theagenteconomy.si/listings/a2a): Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP using JSON-RPC. - [Accords](https://theagenteconomy.si/listings/accords): Transaction infrastructure that structures supply, rights, workflows, and proof for asset and capacity markets. Its open CLP protocol binds signatures, authorization, and payment events into content-addressed proof bundles. - [Agent Network Protocol](https://theagenteconomy.si/listings/anp): Protocol suite whose 1.2 release covers agent identity, naming, description, and discovery, with DID authentication for did:wba and did:web. Authorization and payment specs are still drafts, and group end to end encryption is a candidate. - [Agentic Commerce Protocol](https://theagenteconomy.si/listings/agentic-commerce-protocol): Open standard for an agent to browse a catalog, run a checkout session, and pass a delegated payment to a business. - [AGNTCY](https://theagenteconomy.si/listings/agntcy): Open stack, hosted by the Linux Foundation, for cross vendor agent discovery, identity, messaging, and observability. - [Akash Network](https://theagenteconomy.si/listings/akash-network): Decentralized compute marketplace where independent providers bid to host workloads. - [AP2](https://theagenteconomy.si/listings/ap2): Open payment extension for A2A and UCP that records checkout and payment authorization as signed mandates. Public samples exist while FIDO continues the standards work. - [Bittensor](https://theagenteconomy.si/listings/bittensor): Open network where independent subnets produce digital commodities and the chain pays contributors. - [Claude Agent SDK](https://theagenteconomy.si/listings/claude-agent-sdk): Library that runs the Claude Code agent loop in a process you operate, with built in tools, permissions, sessions, hooks, and subagents. - [Coinbase Agentic Wallet](https://theagenteconomy.si/listings/coinbase-agentic-wallet): Wallet for agents on Coinbase Developer Platform. The agent holds USDC, sends, trades, and pays x402 services through the awal CLI and skills, under per session and per transaction caps, while keys stay in Coinbase infrastructure. The MCP version is labeled beta. - [CrewAI](https://theagenteconomy.si/listings/crewai): Open source framework that pairs event driven Flows for control flow with Crews of role based agents that collaborate on a delegated task. - [ERC-8004](https://theagenteconomy.si/listings/erc-8004): Draft Ethereum proposal for three registries: an ERC-721 identity that points at an agent registration file, a reputation registry, and a validation registry. - [Gensyn](https://theagenteconomy.si/listings/gensyn): Open infrastructure where humans and machines trade compute, data, and information in on-chain markets, with a peer-to-peer layer that carries MCP and A2A. - [Google ADK](https://theagenteconomy.si/listings/google-adk): Open source framework for building, debugging, and deploying agents, including graph workflows and multi agent orchestration. - [Guardrails AI](https://theagenteconomy.si/listings/guardrails-ai): Python framework that runs input and output guards to detect and mitigate specific risks, and can also extract structured data from model output. - [Hedera Agent Accounts](https://theagenteconomy.si/listings/hedera-agent-accounts): Owner funded spending account on Hedera. The owner sets a daily cap, a per transaction maximum, and a recipient allowlist in a smart contract, and can revoke the agent. Hedera says public testnet access is still forthcoming. - [Invariant](https://theagenteconomy.si/listings/invariant): Contextual security layer that checks an agent trace against declarative rules for tool calls, data flow, secrets, and looping. - [L402](https://theagenteconomy.si/listings/l402): HTTP 402 flow that pairs a macaroon with a Lightning invoice. The client pays, then presents the preimage so the server can check payment without a lookup. - [Lakera Guard](https://theagenteconomy.si/listings/lakera-guard): Guard API that screens an agent conversation in one call, including tool definitions, tool calls, and tool results, against a project policy. - [LangGraph](https://theagenteconomy.si/listings/langgraph): Low level orchestration runtime for long running stateful agents, with durable execution and human checkpoints inside the graph. - [LiteLLM Proxy](https://theagenteconomy.si/listings/litellm): Open source proxy that enforces personal, team, and agent spend budgets on model calls when a database is connected, and can attach guardrails. - [Machine Payments Protocol](https://theagenteconomy.si/listings/mpp): Open HTTP 402 protocol, co-authored by Stripe and Tempo, so an agent can authorize payment for an API with a card or a stablecoin and receive a receipt. - [Mastra](https://theagenteconomy.si/listings/mastra): Open source TypeScript framework for agents and workflows, with memory, tool approvals, and processors that can block or redact content. - [MetaMask Agent Wallet](https://theagenteconomy.si/listings/metamask-agent-wallet): Agent wallet CLI for sending tokens and paying x402 requests. Guard Mode can enforce address and recipient allowlists and a rolling 24 hour outflow limit, and it asks for 2FA outside that policy. - [Microsoft Agent Framework](https://theagenteconomy.si/listings/microsoft-agent-framework): Open framework for building and orchestrating agents and multi agent workflows in Python and .NET, with graph workflows and human checkpoints. - [Microsoft Entra Agent ID](https://theagenteconomy.si/listings/entra-agent-id): Identity platform that creates agent identities from blueprints and applies Entra access policy, risk checks, and audit logs to them. - [Model Context Protocol](https://theagenteconomy.si/listings/mcp): Open protocol that connects LLM applications to external tools, resources, and prompts through a standard request interface. - [NeMo Guardrails](https://theagenteconomy.si/listings/nemo-guardrails): Open source toolkit for programmable rails that block, alter, or validate user inputs, model responses, and tool calls. - [Nevermined](https://theagenteconomy.si/listings/nevermined): Payments facilitator that verifies and settles x402 and MPP charges against a payment plan, with metering and delegated card spending. - [Olas Mech Marketplace](https://theagenteconomy.si/listings/olas-mech-marketplace): Marketplace where an agent can hire a specialized agent for a task and pay in crypto, or list its own service for other agents to hire. - [Open Policy Agent](https://theagenteconomy.si/listings/open-policy-agent): Open source policy engine. An application sends structured input and OPA returns a decision from Rego policy, separate from the code that enforces it. - [OpenAI Agents SDK](https://theagenteconomy.si/listings/openai-agents-sdk): Library that runs an agent loop in your application, with tools, handoffs, guardrails, sessions, and human approval before a tool runs. - [PACT](https://theagenteconomy.si/listings/pact): Protocol on A2A 1.0 that lets a personal agent sign its requests and act for a user only inside scopes that user approved with a brand. - [Personal Agent Protocol](https://theagenteconomy.si/listings/personal-agent-protocol): Draft protocol for a company to publish how a personal agent may sign in and act on a person's account, using OAuth, OpenAPI, and MCP. - [Polygon Agent CLI](https://theagenteconomy.si/listings/polygon-agent-cli): Agent CLI with an embedded smart wallet. Session mode spends only inside an allowance the owner approves, x402 payments can be capped per call, and session logout revokes that install. - [Pydantic AI](https://theagenteconomy.si/listings/pydantic-ai): Typed Python agent SDK with structured outputs, guardrails, and companion packages for graph control flow and spending limits. - [Render Network](https://theagenteconomy.si/listings/render-network): Peer to peer marketplace that matches GPU supply with demand for rendering and machine learning jobs. - [Skyfire](https://theagenteconomy.si/listings/skyfire): Issues signed KYAPay tokens that bind an agent identity to a payment the buyer has committed, which the seller charges after delivery. - [smolagents](https://theagenteconomy.si/listings/smolagents): Open source Python library whose code agents write actions as code, with an option to run that code in a sandbox. - [Strands Agents](https://theagenteconomy.si/listings/strands-agents): Open source SDK that runs a model driven agent loop, with hooks, execution limits, and guardrails around each step. - [Stripe link-cli](https://theagenteconomy.si/listings/stripe-link-cli): CLI for an agent to request a card purchase or a Machine Payments Protocol charge. Link asks the customer to approve the spend request, then returns a one time payment credential. - [Sui Agentic Payments](https://theagenteconomy.si/listings/sui-agentic-payments): Testnet gateway where an agent pays per API call in USDC on Sui. The owner sets an onchain grant with allowed services, a total budget, a per payment cap, and an expiry, and can revoke it. - [Tempo Wallet](https://theagenteconomy.si/listings/tempo-wallet): Wallet and CLI that let an agent discover paid services, preview MPP terms, and pay under a max spend cap. - [Universal Commerce Protocol](https://theagenteconomy.si/listings/ucp): Open commerce protocol so agents, businesses, and payment providers can negotiate checkout and identity linking over REST, MCP, or A2A. - [Virtuals Protocol](https://theagenteconomy.si/listings/virtuals-protocol): Agent commerce protocol where agents discover services, negotiate jobs, coordinate execution, and settle payments with each other. - [Visa Trusted Agent Protocol](https://theagenteconomy.si/listings/visa-trusted-agent-protocol): Visa specification for merchants to verify an approved agent from an RFC 9421 HTTP message signature bound to the site and the action, with optional consumer and payment identifiers. Visa reports live agent purchases at European merchants through it and its Agent Directory. - [Web Bot Auth](https://theagenteconomy.si/listings/web-bot-auth): Method for an automated client to sign HTTP requests so a site can verify which bot or agent sent them. The signature rules are an IETF working group draft, not yet a standard. - [x402](https://theagenteconomy.si/listings/x402): Open HTTP payment standard. A server answers with status 402, the client pays and retries, and a facilitator can verify and settle the payment. ## Comparisons - [Agent spend controls compared](https://theagenteconomy.si/compare/spend-controls): This page lists spend controls that vendor documents state for agent use. A filled cell links the document that was checked. If that document does not state the control, the cell says UNKNOWN. Last verified 2026-10-19. There are 14 UNKNOWN cells out of 63. - [A2A vs AGNTCY](https://theagenteconomy.si/compare/a2a-vs-agntcy): A2A and AGNTCY are Protocols listings set side by side. A2A is live. AGNTCY is live. Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP using JSON-RPC. Open stack, hosted by the Linux Foundation, for cross vendor agent discovery, identity, messaging, and observability. - [A2A vs Agent Network Protocol](https://theagenteconomy.si/compare/a2a-vs-anp): A2A and Agent Network Protocol are Protocols listings set side by side. A2A is live. Agent Network Protocol is beta. Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP using JSON-RPC. - [A2A vs Model Context Protocol](https://theagenteconomy.si/compare/a2a-vs-mcp): A2A and Model Context Protocol are Protocols listings set side by side. A2A is live. Model Context Protocol is live. Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP using JSON-RPC. - [Agentic Commerce Protocol vs Universal Commerce Protocol](https://theagenteconomy.si/compare/agentic-commerce-protocol-vs-ucp): Agentic Commerce Protocol and Universal Commerce Protocol are Protocols listings set side by side. Agentic Commerce Protocol is live. Universal Commerce Protocol is live. Open standard for an agent to browse a catalog, run a checkout session, and pass a delegated payment to a business. - [Akash Network vs Gensyn](https://theagenteconomy.si/compare/akash-network-vs-gensyn): Akash Network and Gensyn are Exchanges and markets listings set side by side. Akash Network is live. Gensyn is live. Decentralized compute marketplace where independent providers bid to host workloads. Open infrastructure where humans and machines trade compute, data, and information in on-chain markets, with a peer-to-peer layer that carries MCP and A2A. - [Akash Network vs Render Network](https://theagenteconomy.si/compare/akash-network-vs-render-network): Akash Network and Render Network are Exchanges and markets listings set side by side. Akash Network is live. Render Network is live. Decentralized compute marketplace where independent providers bid to host workloads. Peer to peer marketplace that matches GPU supply with demand for rendering and machine learning jobs. - [AP2 vs Machine Payments Protocol](https://theagenteconomy.si/compare/ap2-vs-mpp): AP2 and Machine Payments Protocol are Payment rails listings set side by side. AP2 is beta. Machine Payments Protocol is live. Open payment extension for A2A and UCP that records checkout and payment authorization as signed mandates. Public samples exist while FIDO continues the standards work. - [Claude Agent SDK vs OpenAI Agents SDK](https://theagenteconomy.si/compare/claude-agent-sdk-vs-openai-agents-sdk): Claude Agent SDK and OpenAI Agents SDK are Frameworks and runtimes listings set side by side. Claude Agent SDK is live. OpenAI Agents SDK is live. Library that runs the Claude Code agent loop in a process you operate, with built in tools, permissions, sessions, hooks, and subagents. - [CrewAI vs LangGraph](https://theagenteconomy.si/compare/crewai-vs-langgraph): CrewAI and LangGraph are Frameworks and runtimes listings set side by side. CrewAI is live. LangGraph is live. Open source framework that pairs event driven Flows for control flow with Crews of role based agents that collaborate on a delegated task. - [Microsoft Entra Agent ID vs ERC-8004](https://theagenteconomy.si/compare/entra-agent-id-vs-erc-8004): Microsoft Entra Agent ID and ERC-8004 are Identity and trust listings set side by side. Microsoft Entra Agent ID is live. ERC-8004 is designed. Identity platform that creates agent identities from blueprints and applies Entra access policy, risk checks, and audit logs to them. - [Microsoft Entra Agent ID vs Web Bot Auth](https://theagenteconomy.si/compare/entra-agent-id-vs-web-bot-auth): Microsoft Entra Agent ID and Web Bot Auth are Identity and trust listings set side by side. Microsoft Entra Agent ID is live. Web Bot Auth is beta. Identity platform that creates agent identities from blueprints and applies Entra access policy, risk checks, and audit logs to them. - [Google ADK vs Microsoft Agent Framework](https://theagenteconomy.si/compare/google-adk-vs-microsoft-agent-framework): Google ADK and Microsoft Agent Framework are Frameworks and runtimes listings set side by side. Google ADK is live. Microsoft Agent Framework is live. Open source framework for building, debugging, and deploying agents, including graph workflows and multi agent orchestration. - [Guardrails AI vs NeMo Guardrails](https://theagenteconomy.si/compare/guardrails-ai-vs-nemo-guardrails): Guardrails AI and NeMo Guardrails are Governance and mandates listings set side by side. Guardrails AI is live. NeMo Guardrails is live. Python framework that runs input and output guards to detect and mitigate specific risks, and can also extract structured data from model output. - [Invariant vs Open Policy Agent](https://theagenteconomy.si/compare/invariant-vs-open-policy-agent): Invariant and Open Policy Agent are Governance and mandates listings set side by side. Invariant is live. Open Policy Agent is live. Contextual security layer that checks an agent trace against declarative rules for tool calls, data flow, secrets, and looping. - [L402 vs x402](https://theagenteconomy.si/compare/l402-vs-x402): L402 and x402 are Payment rails listings set side by side. L402 is live. x402 is live. HTTP 402 flow that pairs a macaroon with a Lightning invoice. The client pays, then presents the preimage so the server can check payment without a lookup. - [Machine Payments Protocol vs x402](https://theagenteconomy.si/compare/mpp-vs-x402): Machine Payments Protocol and x402 are Payment rails listings set side by side. Machine Payments Protocol is live. x402 is live. Open HTTP 402 protocol, co-authored by Stripe and Tempo, so an agent can authorize payment for an API with a card or a stablecoin and receive a receipt. - [Olas Mech Marketplace vs Virtuals Protocol](https://theagenteconomy.si/compare/olas-mech-marketplace-vs-virtuals-protocol): Olas Mech Marketplace and Virtuals Protocol are Exchanges and markets listings set side by side. Olas Mech Marketplace is live. Virtuals Protocol is live. Marketplace where an agent can hire a specialized agent for a task and pay in crypto, or list its own service for other agents to hire. - [PACT vs Personal Agent Protocol](https://theagenteconomy.si/compare/pact-vs-personal-agent-protocol): PACT and Personal Agent Protocol are Protocols listings set side by side. PACT is beta. Personal Agent Protocol is designed. Protocol on A2A 1.0 that lets a personal agent sign its requests and act for a user only inside scopes that user approved with a brand. - [Pydantic AI vs smolagents](https://theagenteconomy.si/compare/pydantic-ai-vs-smolagents): Pydantic AI and smolagents are Frameworks and runtimes listings set side by side. Pydantic AI is live. smolagents is live. Typed Python agent SDK with structured outputs, guardrails, and companion packages for graph control flow and spending limits. Open source Python library whose code agents write actions as code, with an option to run that code in a sandbox. - [Skyfire vs Tempo Wallet](https://theagenteconomy.si/compare/skyfire-vs-tempo-wallet): Skyfire and Tempo Wallet are Payment rails listings set side by side. Skyfire is live. Tempo Wallet is live. Issues signed KYAPay tokens that bind an agent identity to a payment the buyer has committed, which the seller charges after delivery. - [Visa Trusted Agent Protocol vs Web Bot Auth](https://theagenteconomy.si/compare/visa-trusted-agent-protocol-vs-web-bot-auth): Visa Trusted Agent Protocol and Web Bot Auth are Identity and trust listings set side by side. Visa Trusted Agent Protocol is live. Web Bot Auth is beta. Last verified 2026-10-19 and 2026-10-19. Shared tags are http-signatures. The table cites each listing's sources. ## Filters - [Agent governance and mandates](https://theagenteconomy.si/best/agent-governance): Agent governance and mandates lists 6 Governance and mandates entries in alphabetical order. Every governance and mandate listing, listed alphabetically by name. Nothing on the page is scored. The names are Guardrails AI, Invariant, Lakera Guard, LiteLLM Proxy, NeMo Guardrails, Open Policy Agent. - [Agent identity and trust](https://theagenteconomy.si/best/agent-identity): Agent identity and trust lists 4 Identity and trust entries in alphabetical order. Every identity and trust listing, listed alphabetically by name. Nothing on the page is scored. The names are ERC-8004, Microsoft Entra Agent ID, Visa Trusted Agent Protocol, Web Bot Auth. - [Agent payment rails](https://theagenteconomy.si/best/best-agent-payment-rails): Agent payment rails lists 13 Payment rails entries in alphabetical order. Every payment rail in the directory, listed alphabetically by name. Nothing on the page is scored. The names are AP2, Coinbase Agentic Wallet, Hedera Agent Accounts, L402, Machine Payments Protocol, MetaMask Agent Wallet, Nevermined, Polygon Agent CLI, Skyfire, Stripe link-cli, Sui Agentic Payments, Tempo Wallet, x402. - [Agent protocols](https://theagenteconomy.si/best/agent-protocols): Agent protocols lists 8 Protocols entries in alphabetical order. Every protocol in the directory, listed alphabetically by name. Nothing on the page is scored. The names are A2A, Agent Network Protocol, Agentic Commerce Protocol, AGNTCY, Model Context Protocol, PACT, Personal Agent Protocol, Universal Commerce Protocol. - [Agent service marketplaces](https://theagenteconomy.si/best/agent-service-marketplaces): Agent service marketplaces lists 2 Exchanges and markets entries in alphabetical order. Exchange listings tagged agents, listed alphabetically by name. Nothing on the page is scored. The names are Olas Mech Marketplace, Virtuals Protocol. Last verified 2026-10-16. Each row links the listing and its sources. - [Compute marketplaces](https://theagenteconomy.si/best/compute-marketplaces): Compute marketplaces lists 3 Exchanges and markets entries in alphabetical order. Exchange listings tagged compute, listed alphabetically by name. Nothing on the page is scored. The names are Akash Network, Bittensor, Gensyn. Last verified 2026-10-16. Each row links the listing and its sources. - [HTTP 402 payment rails](https://theagenteconomy.si/best/http-402-payment-rails): HTTP 402 payment rails lists 10 Payment rails entries in alphabetical order. Payment rails tagged http-402, listed alphabetically by name. Nothing on the page is scored. The names are Coinbase Agentic Wallet, L402, Machine Payments Protocol, MetaMask Agent Wallet, Nevermined, Polygon Agent CLI, Stripe link-cli, Sui Agentic Payments, Tempo Wallet, x402. - [Live agent payment rails](https://theagenteconomy.si/best/live-agent-payment-rails): Live agent payment rails lists 10 Payment rails entries in alphabetical order. Payment rails with status live, listed alphabetically by name. Nothing on the page is scored. The names are Coinbase Agentic Wallet, L402, Machine Payments Protocol, MetaMask Agent Wallet, Nevermined, Polygon Agent CLI, Skyfire, Stripe link-cli, Tempo Wallet, x402. - [Multi agent frameworks](https://theagenteconomy.si/best/multi-agent-frameworks): Multi agent frameworks lists 3 Frameworks and runtimes entries in alphabetical order. Frameworks tagged multi-agent, listed alphabetically by name. Nothing on the page is scored. The names are CrewAI, Google ADK, Microsoft Agent Framework. Last verified 2026-10-16. Each row links the listing and its sources. - [Open source agent frameworks](https://theagenteconomy.si/best/open-source-agent-frameworks): Open source agent frameworks lists 9 Frameworks and runtimes entries in alphabetical order. Frameworks and runtimes marked open source, listed alphabetically by name. Nothing on the page is scored. The names are CrewAI, Google ADK, LangGraph, Mastra, Microsoft Agent Framework, OpenAI Agents SDK, Pydantic AI, smolagents, Strands Agents. - [Open source agent governance](https://theagenteconomy.si/best/open-source-governance): Open source agent governance lists 4 Governance and mandates entries in alphabetical order. Governance listings marked open source, listed alphabetically by name. Nothing on the page is scored. The names are Guardrails AI, LiteLLM Proxy, NeMo Guardrails, Open Policy Agent. - [Open source payment rails](https://theagenteconomy.si/best/open-source-payment-rails): Open source payment rails lists 6 Payment rails entries in alphabetical order. Payment rails marked open source, listed alphabetically by name. Nothing on the page is scored. The names are AP2, L402, Machine Payments Protocol, Polygon Agent CLI, Stripe link-cli, x402. ## Glossary - [A2A](https://theagenteconomy.si/glossary/a2a): A2A is defined here as follows. Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP. Requests and responses use JSON-RPC 2.0. The directory source for this term is A2A core concepts. - [Agent Card](https://theagenteconomy.si/glossary/agent-card): Agent Card is defined here as follows. JSON document in A2A that lists an agent's identity, capabilities, endpoint, skills, and authentication requirements so a client can decide how to call it. The directory source for this term is A2A core concepts. - [Agent identity](https://theagenteconomy.si/glossary/agent-identity): Agent identity is defined here as follows. An identity created for an agent so access policy, risk checks, and audit logs can apply to it. Microsoft Entra Agent ID creates these identities from blueprints. The directory source for this term is Overview of agent identities in Microsoft Entra. - [Agent mandate](https://theagenteconomy.si/glossary/agent-mandate): Agent mandate is defined here as follows. Signed credential in AP2. A checkout mandate records the cart negotiated with the merchant. A payment mandate authorizes a payment instrument against that checkout. The directory source for this term is AP2 protocol documentation. - [Agent marketplace](https://theagenteconomy.si/glossary/agent-marketplace): Agent marketplace is defined here as follows. A market where an agent can hire a specialized agent for a task and pay for the work, or list its own service for other agents to hire. The directory source for this term is Olas Mech Marketplace. - [Agent wallet](https://theagenteconomy.si/glossary/agent-wallet): Agent wallet is defined here as follows. A wallet an agent can use to discover paid services and pay under a cap the operator set. Tempo Wallet lets an agent preview Machine Payments Protocol terms and pay under a max spend cap. The directory source for this term is Tempo Wallet agent documentation. - [Agentic Commerce Protocol](https://theagenteconomy.si/glossary/agentic-commerce-protocol): Agentic Commerce Protocol is defined here as follows. Open standard for an agent to browse a catalog, run a checkout session, and pass a delegated payment to a business. The directory source for this term is Stripe documentation for the Agentic Commerce Protocol. - [AGNTCY](https://theagenteconomy.si/glossary/agntcy): AGNTCY is defined here as follows. Open stack, hosted by the Linux Foundation, for cross vendor agent discovery, identity, messaging, and observability. The directory source for this term is AGNTCY project site. Last verified 2026-10-17. The directory lists 1 entries that use this term. - [AP2](https://theagenteconomy.si/glossary/ap2): AP2 is defined here as follows. Open payment extension for A2A and the Universal Commerce Protocol. It records checkout and payment authorization as signed mandates. Public samples exist while FIDO continues the standards work. The directory source for this term is AP2 protocol documentation. - [Compute marketplace](https://theagenteconomy.si/glossary/compute-marketplace): Compute marketplace is defined here as follows. A market where independent providers offer compute for workloads. Akash Network documents providers bidding to host those workloads. The directory source for this term is Akash Network introduction. Last verified 2026-10-17. The directory lists 3 entries that use this term. - [Content-addressed proof](https://theagenteconomy.si/glossary/content-addressed-proof): Content-addressed proof is defined here as follows. A CLP proof bundle that binds signatures, authorization, and payment events into a content-addressed record for an asset or capacity transaction. The directory source for this term is Accords OS and CLP. Last verified 2026-10-17. - [Decentralized identifier](https://theagenteconomy.si/glossary/did): Decentralized identifier is defined here as follows. A URI that associates a subject with a DID document. The controller can prove control without permission from a centralized registry, identity provider, or certificate authority. The directory source for this term is W3C Decentralized Identifiers v1.0. - [Digital commodity](https://theagenteconomy.si/glossary/digital-commodity): Digital commodity is defined here as follows. Work product of an open network where independent subnets produce digital commodities and the chain pays contributors. The directory source for this term is Bittensor site. Last verified 2026-10-17. The directory lists 1 entries that use this term. - [ERC-8004](https://theagenteconomy.si/glossary/erc-8004): ERC-8004 is defined here as follows. Draft Ethereum proposal for three registries: an ERC-721 identity that points at an agent registration file, a reputation registry, and a validation registry. The directory source for this term is ERC-8004 Trustless Agents. Last verified 2026-10-17. - [Guardrail](https://theagenteconomy.si/glossary/guardrail): Guardrail is defined here as follows. Programmable check that can block, alter, or validate user input, model output, or a tool call. NeMo Guardrails runs these checks as rails around an LLM application. The directory source for this term is NVIDIA NeMo Guardrails overview. - [HTTP 402](https://theagenteconomy.si/glossary/http-402): HTTP 402 is defined here as follows. HTTP status code 402, Payment Required. RFC 9110 reserves the code for future use. x402, L402, and the Machine Payments Protocol use a 402 response as the signal that the request needs payment. The directory source for this term is RFC 9110, status 402 Payment Required. - [Human approval](https://theagenteconomy.si/glossary/human-approval): Human approval is defined here as follows. A pause where a person inspects or changes agent state before the run continues. LangGraph provides this inside the graph. The directory source for this term is LangGraph overview. Last verified 2026-10-17. The directory lists 4 entries that use this term. - [JSON-RPC](https://theagenteconomy.si/glossary/json-rpc): JSON-RPC is defined here as follows. Stateless remote procedure call protocol. A request is a JSON object naming a method, with optional parameters and an id, and the server returns a JSON result or error. The directory source for this term is JSON-RPC 2.0 specification. - [KYAPay](https://theagenteconomy.si/glossary/kyapay): KYAPay is defined here as follows. Signed token from Skyfire that binds an agent identity to a payment the buyer has committed. The seller charges the token after delivery. The directory source for this term is Skyfire KYAPay token documentation. - [L402](https://theagenteconomy.si/glossary/l402): L402 is defined here as follows. HTTP 402 flow from Lightning Labs. The server returns a macaroon and a Lightning invoice. The client pays, then presents the preimage so the server can check payment without a lookup. The directory source for this term is Lightning Labs L402 documentation. - [Machine Payments Protocol](https://theagenteconomy.si/glossary/machine-payments-protocol): Machine Payments Protocol is defined here as follows. Open HTTP 402 protocol, co-authored by Stripe and Tempo, so an agent can authorize payment for an API with a card or a stablecoin and receive a receipt. The directory source for this term is Stripe documentation for MPP. - [Model Context Protocol](https://theagenteconomy.si/glossary/mcp): Model Context Protocol is defined here as follows. Open protocol that connects an LLM application to external tools, resources, and prompts. Hosts, clients, and servers exchange JSON-RPC 2.0 messages. The directory source for this term is Model Context Protocol specification. - [Multi agent](https://theagenteconomy.si/glossary/multi-agent): Multi agent is defined here as follows. More than one agent collaborating under a runtime. CrewAI pairs event driven Flows for control flow with Crews of role based agents that share a delegated task. The directory source for this term is CrewAI introduction. - [PACT](https://theagenteconomy.si/glossary/pact): PACT is defined here as follows. Protocol on A2A 1.0 that lets a personal agent sign its requests and act for a user only inside scopes that user approved with a brand. The directory source for this term is PACT protocol overview. - [Payment facilitator](https://theagenteconomy.si/glossary/payment-facilitator): Payment facilitator is defined here as follows. A service that verifies a payment and settles it for the seller. In x402 the server asks the facilitator to verify, does the work, then asks the facilitator to settle. The directory source for this term is Coinbase documentation for how x402 works. - [Personal Agent Protocol](https://theagenteconomy.si/glossary/personal-agent-protocol): Personal Agent Protocol is defined here as follows. Draft protocol for a company to publish how a personal agent may sign in and act on a person's account, using OAuth, OpenAPI, and MCP. The directory source for this term is Personal Agent Protocol overview. - [Policy engine](https://theagenteconomy.si/glossary/policy-engine): Policy engine is defined here as follows. Software that returns a decision from policy code, separate from the application that enforces it. Open Policy Agent evaluates structured input against Rego policy. The directory source for this term is Open Policy Agent documentation. - [Spend limit](https://theagenteconomy.si/glossary/spend-limit): Spend limit is defined here as follows. A budget on model calls. LiteLLM Proxy enforces personal, team, and agent spend budgets when a database is connected. The directory source for this term is LiteLLM proxy budgets. Last verified 2026-10-17. The directory lists 9 entries that use this term. - [Tool call](https://theagenteconomy.si/glossary/tool-call): Tool call is defined here as follows. A function an MCP server exposes for a model to execute. The MCP specification treats a tool as code execution and says hosts must get explicit user consent before invoking one. The directory source for this term is Model Context Protocol specification. - [Universal Commerce Protocol](https://theagenteconomy.si/glossary/ucp): Universal Commerce Protocol is defined here as follows. Open commerce protocol so agents, businesses, and payment providers can negotiate checkout and identity linking over REST, MCP, or A2A. The directory source for this term is Universal Commerce Protocol specification. Last verified 2026-10-17. - [Web Bot Auth](https://theagenteconomy.si/glossary/web-bot-auth): Web Bot Auth is defined here as follows. Method for an automated client to sign HTTP requests so a site can verify which bot or agent sent them. The signature rules are still an IETF draft. The directory source for this term is Cloudflare Web Bot Auth documentation. - [x402](https://theagenteconomy.si/glossary/x402): x402 is defined here as follows. Open standard for per request HTTP payments. The server quotes a price, the client sends the request again with proof of payment, and a facilitator can verify and settle it. The directory source for this term is Coinbase documentation for how x402 works. ## Stats - [x402 adoption, claimed vs measured](https://theagenteconomy.si/stats/x402-adoption): This page quotes x402 adoption as a vendor claim beside an independent measurement, both checked on 2026-10-19. The claim is published by x402 in x402.org Last 30 Days panel. The measurement is published by x402scan in x402scan overall stats. The two sides use different metric labels. This page does not compute a ratio or a gap. ## Optional - [Full text](https://theagenteconomy.si/llms-full.txt): Plain text of every listing, comparison, filter, and glossary term. - [Listings dataset](https://theagenteconomy.si/data/listings.json): JSON records under CC BY 4.0. - [Stats index](https://theagenteconomy.si/stats): Stats pages on this site quote a public figure only when a source and a date are both on the page. The published stat page is x402 adoption, checked on 2026-10-19. 8 other payment rails have claimed and measured adoption marked UNKNOWN. - [Comparisons index](https://theagenteconomy.si/compare): This index lists 21 comparison pages plus the spend controls matrix. Each comparison places two listings from the same category side by side and restates their mechanisms. Nothing on these pages is scored. The spend controls page marks a cell UNKNOWN when the checked document does not state the control. - [Glossary index](https://theagenteconomy.si/glossary): This glossary defines 32 mechanisms used across the directory. Each term has one public source, a last verified date, and the listings that use the term. Definitions describe the mechanism. The newest verification date among the terms is 2026-10-17. Related terms link in both directions. - [Filters index](https://theagenteconomy.si/best): This index lists 12 filters over the directory. Each filter narrows one category by status, open source, or tag, then lists matches alphabetically. A filter has to match at least two listings. Verification dates are taken from the matched listings. Site: https://theagenteconomy.si