A curated list of infrastructure for autonomous machine-to-machine commerce — where AI agents discover, trust, and pay each other.
The machine economy is the infrastructure layer where AI agents operate as economic participants: they hold funds, build reputation, discover services, negotiate terms, and settle payments — all without human intervention. This list covers the building blocks.
- The Stack
- Identity and Trust
- Smart Accounts
- Payments
- Discovery and Registries
- Reputation
- Messaging and Communication
- Agent Frameworks
- MCP Servers
- Developer Tools
- Standards
- Research
Machines participating in the economy need the same things humans need: an identity, a wallet, a way to find services, a way to communicate, and a way to pay. The difference is everything must be programmable, verifiable, and autonomous.
Identity ─── Who am I? Can you trust me?
│
Account ──── Where do I hold funds? What are my limits?
│
Discovery ── How do I find the right service?
│
Messaging ── How do we negotiate and coordinate?
│
Payment ──── How do I pay and get paid?
│
Reputation ─ Did it go well? Would I use them again?
Each layer below maps to a part of this stack.
How machines prove who they are and establish trust.
- ERC-8004 - Machine economy trust registry. On-chain identity, reputation, and validation for agents, services, and infrastructure. ERC-721 based.
- Ethereum Attestation Service (EAS) - On-chain and off-chain attestation infrastructure. Schema-based, composable attestations.
- Verax - Attestation registry on Linea. Composable on-chain trust signals.
- Olas Registry - On-chain agent registration via NFTs. Staking-based commitment signals.
- ENS - Human-readable names for addresses and service endpoints.
- ERC-8128 - Sign-in with agents. HTTP challenge-response authentication using smart account signatures.
- SIWE (Sign-In with Ethereum) - Authentication standard for Ethereum wallets. Foundation for agent auth flows.
- W3C Decentralized Identifiers - Self-sovereign identity standard. Underlies many agent identity systems.
- W3C Verifiable Credentials - Cryptographically verifiable claims. Used by Google AP2 for agent authorization.
- Azeth - ERC-8004 identity, on-chain reputation, guardian-protected smart accounts, x402 payments, and service discovery in one SDK. MCP server with 30+ tools for AI agents. (GitHub | npm)
Programmable wallets with enforced limits — machines that can hold and spend funds safely.
- ERC-4337 - Account abstraction. UserOperations, bundlers, paymasters. Smart accounts can pay gas in any token.
- ERC-7579 - Modular smart accounts. Validators, executors, hooks — interoperable across implementations.
- ERC-7715 - Session keys. Time-bounded, amount-limited, scope-restricted delegated signing.
- ERC-6900 - Modular account standard (alternative to 7579). Plugin-based architecture.
- ZeroDev - Modular smart account SDK. Session keys, batched transactions, gas sponsorship. ERC-7579 native.
- Safe - Multi-sig and modular smart accounts. $100B+ secured. Extensive module ecosystem.
- Biconomy - Smart account platform with session keys, paymaster, and bundler.
- Coinbase Smart Wallet - Passkey-based smart accounts on Base. Gas sponsorship built in.
- Pimlico - ERC-4337 bundler and paymaster. Alto (open-source bundler).
- Stackup - ERC-4337 bundler and paymaster infrastructure.
- Alchemy Account Kit - Smart account SDK with embedded wallets and gas management.
How machines pay each other — from micropayments to streaming to subscriptions.
The HTTP-native payment protocol. Server returns 402 with payment requirements, client pays on-chain, retries with proof.
- x402 Protocol - The specification. Coinbase + Cloudflare. USDC-native, middleware-friendly.
- @x402/hono - x402 middleware for Hono.
- @x402/express - x402 middleware for Express.
- @x402/fetch - Fetch wrapper that auto-handles 402 responses.
- @azeth/provider - x402 provider tooling. Pre-settled smart account payments, SIWx sessions, payment agreements. (GitHub)
- xPay Facilitator - Open x402 facilitator. No auth required.
- Google AP2 - Agent payment authorization. Payment-agnostic, Verifiable Credentials for audit trails.
- OpenAI ACP - Agentic Commerce Protocol. Stripe-powered checkout for ChatGPT and consumer AI.
- Visa TAP - Trusted Agent Protocol. TradFi-to-crypto agent payment bridge.
- Mastercard Agent Pay - Tokenized payments and agent wallet integration via card networks.
- Superfluid - Real-time payment streaming. Pay per second for continuous services.
- Sablier - Token streaming. Linear and dynamic payment schedules.
- Lightning Network - Bitcoin L2. Sub-second settlement, near-zero fees.
- Pay3 - Stablecoin automation for agents. USDC/USDT autonomous payouts.
How machines find the right service for a task.
- ERC-8004 - On-chain trust registry. Query by capability, entity type, reputation. Universal for agents, services, and infrastructure.
- Google A2A Agent Cards - JSON manifests at
/.well-known/agent.json. Describe capabilities, skills, and interaction modes. - Glama - MCP server directory. Search, verify, and browse Model Context Protocol servers.
- Smithery - MCP server hosting and marketplace. Deploy and discover MCP servers.
- mcp.so - MCP server registry. Searchable directory with install instructions.
- PulseMCP - MCP server directory with categories and ratings.
- Olas - Decentralized agent registry. NFT-based, staking-required registration.
How machines build track records — objective, on-chain, payment-weighted.
- ERC-8004 Reputation Registry - On-chain reputation linked to identity entries. Stores feedback per interaction.
- Azeth Reputation - Multi-dimensional scoring: uptime, response time, success rate, volume. Auto-feedback after every x402 payment. Reputation-aware service routing.
- Karma3Labs - EigenTrust-based reputation. Compute global trust from local interactions via graph algorithms.
- Gitcoin Passport - Sybil-resistance via composable identity stamps. Aggregate proofs into a single score.
- DegenScore - On-chain reputation for DeFi. Soulbound tokens as proof of expertise.
- Orange Protocol - Reputation and trust infrastructure. Composable reputation models.
How machines negotiate, coordinate, and stream results.
- XMTP - E2E encrypted messaging for wallets and agents. Discovery via address. (Agent SDK)
- Google A2A - Agent-to-agent protocol. Task lifecycle, streaming, push notifications.
- IBM ACP - Agent Communication Protocol. Cross-framework messaging with human-in-the-loop.
- Waku - Decentralized messaging protocol. Privacy-preserving, censorship-resistant.
- Model Context Protocol (MCP) - Anthropic's AI-to-tool protocol. Tools, resources, prompts. Adopted by Claude, Cursor, Windsurf.
- OpenAI Function Calling - Structured tool use for GPT models.
- LangChain Tools - Tool abstraction layer for LLM applications.
Frameworks for building AI agents that participate in the economy.
- LangGraph - Graph-based agent orchestration. Multi-agent workflows, persistence, human-in-the-loop.
- CrewAI - Multi-agent collaboration. Role-based agents with delegation and task management.
- OpenAI Agents SDK - Official OpenAI agent framework. Tool use, handoffs, guardrails.
- AutoGPT - Autonomous AI agent platform. Long-running tasks, web interaction.
- OpenClaw - Personal AI assistant. Cross-platform, skill-based architecture.
- Eliza - Multi-agent simulation. Character-based agents with social interaction.
- CAMEL - Multi-agent communication framework for large-scale agent behavior.
MCP servers for payments, DeFi, and machine economy operations.
- Azeth MCP - Smart accounts, x402 payments, reputation, discovery, messaging. 30+ tools. (GitHub)
- Coinbase AgentKit - Wallet management, transfers, DeFi on Base.
- deBridge MCP - Cross-chain swaps and bridges.
- Stripe Agent Toolkit - Payment processing, invoicing, subscriptions.
- Uniswap MCP - DEX swaps and liquidity.
- 1inch MCP - DEX aggregator for optimal swap routing.
- Aave MCP - Lending and borrowing protocol tools.
See awesome-mcp-servers for the comprehensive MCP directory.
SDKs, CLIs, and infrastructure for building in the machine economy.
- Azeth SDK - TypeScript SDK. Smart accounts, x402 payments, reputation, discovery, messaging. (GitHub)
- Azeth CLI - Register, discover, pay, and manage machine participants from the terminal.
- viem - TypeScript Ethereum library. Type-safe, tree-shakeable.
- ethers.js - Complete Ethereum library. Widely adopted.
- wagmi - React hooks for Ethereum.
- Foundry - Smart contract toolchain. Fast compilation, native fuzzing, Solidity testing.
- Hardhat - Ethereum development environment. Testing, debugging, deployment.
- Tenderly - Smart contract monitoring, debugging, and simulation.
| Standard | What it does | Status |
|---|---|---|
| ERC-4337 | Account abstraction | Final |
| ERC-6900 | Modular accounts (alt) | Draft |
| ERC-7579 | Modular accounts | Draft |
| ERC-7715 | Session keys | Draft |
| ERC-8004 | Trust registry | Draft |
| ERC-8128 | Agent authentication | Draft |
| x402 | HTTP payments | Active |
| MCP | AI-to-tool protocol | Active |
| A2A | Agent-to-agent protocol | Active |
| CAIP-2 | Chain identifiers | Final |
| CAIP-10 | Account identifiers | Final |
- Coinbase: x402 Vision - HTTP 402 as the internet's native payment layer.
- a16z: Crypto x AI - Why crypto infrastructure matters for autonomous agents.
- Vitalik: Account Abstraction Roadmap - The path to smart accounts as default.
- McKinsey: AI Agent Economy - $5T projected market by 2030.
- Gartner: Agentic AI - Enterprise agent adoption trends and forecasts.
Contributions welcome. See CONTRIBUTING.md for guidelines.
