Startups building payment and identity rails for AI agents transacting autonomously

1. Skyfire — Builds an AI-native payment network with agent wallets, USDC settlement, and “Know Your Agent/Wallet” identity controls. Why it fits: One of the clearest pure-play examples; early-stage company with a product explicitly designed for autonomous agents and announced enterprise/payment-network partnerships.
2. Payman AI — Lets AI agents hold spending balances and pay people or services through programmable payment accounts. Why it fits: YC-backed early startup focused directly on agent-to-human and agent-to-service payments, with a strong signal from its public agent-payment product.
3. Nevermined — Provides payment, metering, and access-control infrastructure for AI agents and agentic services. Why it fits: Early company building an “AI commerce” protocol rather than a general-purpose crypto wallet, with funding and ecosystem activity around machine-to-machine payments.
4. Kite AI — Developing an AI-focused blockchain and identity/payment layer for agents, including persistent agent identities and programmable transactions. Why it fits: Very early, purpose-built infrastructure company whose core thesis is autonomous agents transacting with one another and with businesses.
5. Fewsats — Offers a marketplace and payment protocol allowing AI agents to purchase digital services using Bitcoin Lightning. Why it fits: YC-backed and unusually concrete: agents can discover, pay for, and consume services without a human checkout step.
6. Crossmint — Provides embedded wallets, programmable accounts, payments, and compliance tooling that applications can use to give AI agents controlled spending capabilities. Why it fits: Venture-backed infrastructure company increasingly positioned around agent wallets and machine-native commerce; its wallet and payment primitives are already production-oriented.
7. Turnkey — Supplies secure wallet infrastructure and programmable key management for applications, including autonomous software agents. Why it fits: Early, well-funded custody/key-management startup; its policy engine and secure signing model address the critical problem of letting agents transact without giving them unrestricted private-key access.
8. Lit Protocol — Provides programmable cryptographic key management and execution permissions for wallets, credentials, and autonomous agents. Why it fits: Its decentralized signing and condition-based authorization can serve as the identity, permissioning, and transaction-control layer beneath agent wallets; it has credible early crypto-infrastructure traction.
9. ZeroDev — Builds account-abstraction infrastructure, including smart accounts and transaction automation that can be controlled by software agents. Why it fits: Early developer-infrastructure company with a practical route to agent wallets: delegated permissions, session keys, gas abstraction, and policy-controlled execution.
10. Coinbase — Through AgentKit and related payment infrastructure such as x402, enables developers to give agents wallets, blockchain access, and machine-to-machine payment capabilities. Why it fits: Not early or obscure, but one of the strongest commercial signals in the category: a major payments/crypto platform has productized the agent-wallet and agent-payment stack.

White-space gaps noticed

• Portable agent identity and reputation: The market has wallets and signing tools, but little standardized infrastructure for an agent’s portable business identity, permissions, reputation, liability, and revocation across providers and chains.
• Fiat-native agent spending and settlement: Most activity remains crypto- or stablecoin-centric. There is room for a Stripe-like layer handling cards, ACH/wires, tax documentation, refunds, limits, and compliance specifically for autonomous agents.