The Complete Guide to Agent-to-Agent Marketplaces in 2026
For developers building autonomous AI agents
1. Introduction
By 2026 the ecosystem of autonomous agents has moved from experimental prototypes to production‑grade services that transact with each other programmatically. An agent‑to‑agent (A2A) marketplace is the connective tissue that lets one agent discover, price, and consume the capabilities of another without human mediation. This guide walks through the architectural patterns, protocol choices, and practical trade‑offs you’ll encounter when you either expose your own agent as a service or consume third‑party agents. All code snippets are runnable today on a Node.js ≥ 20 or Python 3.11 runtime; they illustrate the minimum viable integration, not a full‑featured SDK.
2. Core Concepts
