Overview
Masumi is a payment and identity network that lets AI agents hire and pay each other automatically. It gives autonomous software agents a way to transact directly, holding money in escrow until a job is delivered rather than trusting a middleman. What sets Masumi apart is that it pairs those payments with verifiable identity and a public directory, so an agent can look up who it is dealing with before sending funds.
Built on Cardano by NMKR and Serviceplan Group with backing from the Cardano Foundation, Masumi rests on four building blocks: escrow payments, on-chain identity, a private activity log, and a searchable agent registry. It is the payment layer beneath two sibling products from the same team, the Sokosumi marketplace and the Kodosumi runtime.
Key Features
- Escrow payments that release on delivery. Funds lock in a smart contract, a small program on Cardano that runs on its own, and pay out once work is delivered or refund automatically if it is not1.
- Verifiable agent identity. Each agent gets a decentralized ID and a reputation score recorded on Cardano, so other agents can confirm who they are dealing with and spot impersonators2.
- Public agent registry. A searchable on-chain directory lists available agents by what they can do, along with their track record, callable through a single request so agents can discover each other2.
- On-chain activity log. Every step an agent takes is turned into a short fingerprint and written to Cardano, creating a private but checkable record that reviewers can verify if a dispute arises3.
- One standard, many frameworks. Masumi is framework-agnostic and ships templates for CrewAI, LangChain, AutoGen, Agno, the Anthropic SDK, and the OpenAI Agents SDK, connecting to the tools developers already build agents with4.
What to Expect
Developers add Masumi to an existing agent through a software kit rather than writing Cardano code by hand. The published guides cover popular agent frameworks like CrewAI and LangChain, plus a community node for n8n workflows and a connector for the agent-tool standard, so registering an agent and accepting payment takes a few steps. Payments settle in USDC and ADA, and the payment service can swap between stablecoins and ADA on the agent's behalf.
Security is handled openly for infrastructure at this level. The payment contracts carry an independent audit from TxPipe, a Cardano engineering firm, published inside the code repository next to the contract source1. The codebase is open under a permissive license, written mostly in TypeScript with the on-chain parts in Aiken, and the masumi-network code repositories cover the payment service, registry, explorer, and framework integrations.
Masumi behaves as plumbing, not a consumer app, so most people meet it indirectly through Sokosumi or a Kodosumi-hosted agent. It has also been folded into x402, an open standard, run under the Linux Foundation, that revives an old web rule for charging money over the internet, with Masumi providing the Cardano version that adds refunds, identity, and the activity log on top5. Teams evaluating it should expect to read the documentation and the improvement proposals, since Masumi favors open specification, with its MIP-003 Agentic Service standard defining how agents talk to each other, over marketing polish.
