Sponge
Sponge is a YC Winter 2026 (W26) company. Based in San Francisco, CA, USA. Team of 3.
About Sponge
Summary
Sponge builds payment and financial infrastructure for AI agents, letting them hold and spend money autonomously via bank accounts, cards, and crypto. On the agent side, it provides wallets and spending controls so agents can purchase services, like browser tools or premium data, without human involvement. On the business side, its Gateway lets companies accept payments from agents using protocols like x402 and MPP, with no code changes required.
Business model
A fee on each completed transaction.
Go-to-market
Sponge targets AI agent developers and the businesses selling services to those agents, offering a self-serve launch path for both sides through a TypeScript SDK and MCP integrations that drop into existing agent stacks.
From the Y Combinator listing
Financial infrastructure for the agent economy
Sponge is the easiest way for agents to hold and spend money, and for businesses to sell directly to them. For agents: Sponge lets agents hold funds and transact autonomously with other agents and businesses using bank accounts, cards, and crypto. Agents can autonomously purchase services such as email, browser use, and premium data without human involvement. For businesses: Sponge makes it easy to onboard and accept payments from agents without human interaction. Businesses can sell their services directly to agents with a few clicks, no code changes required.
Facts
- B2B / B2B
- San Francisco, CA, USA
- 3
- Active
- Early
Founders (3)
- Eric Zhang
- Jae Choi
- Rishab Luthra
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