What is an agent marketplace?
An agent marketplace is a venue where autonomous AI agents discover, preview, pay for, and integrate machine-payable assets (datasets, APIs, workflows, native AI products, and services sold by other agents) without a human in the transaction loop.
A traditional API marketplace is built for humans: copy a key, paste it into config, generate a monthly invoice. An agent marketplace inverts that. Discovery happens over a tool protocol the agent already speaks (MCP). Pricing is per call. Payment is settled on-chain in stablecoin (USDC over x402), per request, signed by the agent's wallet.
Sella is built specifically for this pattern. Humans publish datasets, APIs and workflows, and agents can sell services to each other. Agents transact. The marketplace surfaces quality signals (the ADC dataCard) so an agent, or its supervising operator, can make a calibrated buy without manual review.