AI Agent Protocols: Web of Agents & Machine Discovery
🎯 What You'll Learn
This guide explains the emerging protocols for AI agent communication and discovery. We cover why machine-to-machine protocols are essential for autonomous systems and when to implement different discovery mechanisms — essential knowledge for building AI-native infrastructure.
The Rise of Autonomous AI Systems
2026 marks a fundamental shift in how AI systems interact with the world. Agents no longer simply respond to human prompts — they autonomously discover, evaluate, and invoke services to accomplish complex goals. This requires new protocols designed specifically for machine-to-machine communication.
Key characteristics of modern AI agents:
- Autonomous operation — Execute multi-step tasks without human intervention
- Service discovery — Find and evaluate capabilities programmatically
- Economic participation — Pay for services, receive payment for value
- Context awareness — Maintain state across interactions
Web of Agents (WoA)
Web of Agents defines how services advertise capabilities to AI consumers. Think of it as robots.txt evolved for intelligent machines — a manifest that describes what a service can do, what inputs it needs, and how to invoke it.
Capability Manifests
A WoA manifest describes service capabilities in machine-readable format. Agents parse these manifests to understand what a service offers and how to interact with it.
- Endpoints — Available API paths and methods
- Schemas — Input/output data structures
- Authentication — Required credentials or tokens
- Pricing — Cost per request or subscription models
- Constraints — Rate limits, data restrictions
WoA Manifest Implementation
Complete manifest schema, server configuration, and client parsing library.
Model Context Protocol (MCP)
MCP standardizes how LLMs interact with external tools. It defines a structured format for tool calls, ensuring the model's requests are validated and the responses are properly integrated into context.
| Aspect | Without MCP | With MCP |
|---|---|---|
| Tool calls | Ad-hoc JSON | Validated schemas |
| Errors | String parsing | Structured responses |
| State | Manual tracking | Context management |
| Security | Per-tool | Unified policies |
MCP Server Implementation
Production MCP server with schema validation, context management, and security middleware.
Discovery Mechanisms
Agents need to find services before they can use them. Multiple discovery mechanisms serve different use cases:
Well-Known Endpoints
Services publish manifests at predictable URLs (like /.well-known/woa.json). Simple and widely supported, but requires knowing the domain first.
DNS-Based Discovery
TXT records can advertise agent capabilities, enabling discovery through standard DNS queries. Useful for decentralized discovery without central registries.
Registry Services
Centralized catalogs of agent capabilities. Higher discoverability but introduces dependency on registry availability.
Multi-Modal Discovery
Implementation supporting all three discovery mechanisms with fallback handling.
Economic Protocols
Autonomous agents need to transact autonomously. Several protocols enable machine-to-machine payments:
- x402 / L402 — HTTP 402 Payment Required with Lightning invoices
- Interledger — Streaming micropayments synchronized with data
- Privacy Pass — Anonymous authentication tokens
The combination of capability discovery and payment protocols enables fully autonomous economic agents — systems that find services, negotiate terms, pay, and deliver value without human intervention.
🚀 Build AI-Native Infrastructure
Get access to production agent protocol implementations, including WoA servers, MCP middleware, and payment integration.
Request Access Browse DocumentationExternal Resources
- Model Context Protocol — Official specification
- HTTP Authentication — IETF standards
- Interledger — Payment protocol
- Lightning Network — Bitcoin micropayments