Sponge

AI Agent Payment Infrastructurepaysponge.com

Sponge provides financial infrastructure that lets AI agents autonomously hold wallets, make payments, and process transactions across crypto networks. Founded by ex-Stripe engineers and backed by Y Combinator, the platform serves AI agent developers through SDKs and MCP integrations.

Company typePrivate
Founded2024
HeadquartersSan Francisco, United States
Headcount1–10
GTM typeB2B
OfferingSoftware

What Sponge does

Sponge is a Y Combinator-backed startup that builds financial infrastructure enabling AI agents to autonomously hold wallets, execute payments, and process transactions on cryptocurrency networks. Founded by three ex-Stripe engineers — including Eric Zhang who shipped Stripe's stablecoin payments product — the company targets AI agent developers and builders who need their agents to perform financial operations without human intermediation. Distribution is product-led through TypeScript and Python SDKs, a CLI tool, and MCP (Model Context Protocol) servers that integrate directly with major agent frameworks including Claude Code, ChatGPT, Codex CLI, Cursor, and OpenClaw.

The product portfolio centers on two core products. Sponge Wallet gives agents stablecoin custody, virtual cards, ACH and wire banking, swaps, and trading across EVM chains (Ethereum, Base), Solana, and Tempo. Sponge Gateway is a payment gateway that converts any API into agent-payable endpoints via the x402 (Coinbase) and MPP (Stripe/Tempo) payment protocols, requiring no upstream code changes and supporting OpenAPI import and session-based billing. Supporting products include Sponge Catalog (a directory of pay-per-use API services), Sponge Card (a Visa credit card issued by Rain and collateralized by USDC held in the agent's wallet), and dedicated MCP servers that expose wallet and gateway tools to agent frameworks. The platform also integrates with Hyperliquid for perpetual futures trading and Polymarket for prediction markets.

Sponge's revenue model is transaction-based: Gateway generates take-rate fees on agent payments processed through the marketplace, while Wallet generates revenue through account and transaction fees on fund management. No public pricing, tiers, or contract structures are disclosed, and the company has no enterprise sales motion. The company operates as Sponge Inc., a US-incorporated private entity, with seed-stage funding from Y Combinator including a $500K round in February 2026.

Sponge firmographics

Firmographics

Name: Sponge
Legal name: Sponge Inc.
Website: https://paysponge.com
Company type: Private
Founded year: 2024
Operating status: Operating
Headcount range: 1–10 employees
Short description: Sponge provides financial infrastructure that lets AI agents autonomously hold wallets, make payments, and process transactions across crypto networks. Founded by ex-Stripe engineers and backed by Y Combinator, the platform serves AI agent developers through SDKs and MCP integrations.
Ownership category
akta.pro rank

Sponge industry classification

Industry

Product category: AI Agent Payment Infrastructure
NAICS: Financial Transactions Processing, Reserve, and Clearinghouse Activities (522320)
SIC: Security & Commodity Brokers, Dealers, Exchanges & Services (6200), Finance Services (6199)
akta.pro primary industry: Crypto Payment Gateways & Checkout APIs (FSADAIAA)
akta.pro secondary industries: Wallet Infrastructure (SDKs, Wallet-as-a-Service) (FSADACAD), Digital Wallet Infrastructure (Tokenization, Wallet-as-a-Service) (FSAMAEAI), Invoice, Billing & Subscription Payments (Crypto) (FSADAIAG), Tokenized Collateral & On-Chain Credit Infrastructure (Collateral Mgmt, Liquidations) (FSAGAMAK)

Keywords

AI agent payments
Crypto payment infrastructure
Autonomous agent wallets
X402 payment protocol
API monetization platform

Where Sponge is headquartered

Location

Headquarters

HQ city: San Francisco
HQ country: United States
HQ region: North America

Markets served

Sponge business model

Business model

GTM type: B2B
Offering type: Software
Cost components: Technology or R&D, Personnel, Infrastructure, Operations

Revenue model

Payment Processing (Gateway): Sponge Gateway charges transaction fees on AI agent payments processed through its API marketplace. Revenue is derived from a take rate on each payment transaction executed by AI agents using the platform.
Wallet Infrastructure: Sponge Wallet generates revenue by providing AI agents with bank and crypto account infrastructure, likely through account fees or transaction fees associated with fund management.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Sponge product offering

Product offering

Core offering

Sponge provides financial infrastructure that enables AI agents to autonomously hold wallets, manage funds, and execute payments across crypto networks (Ethereum, Base, Solana, Tempo). Its Sponge Wallet gives agents their own bank and crypto accounts with virtual cards and ACH/wire support, while Sponge Gateway turns any API into a paid endpoint priced and payable by agents via the x402 and MPP open payment protocols. The platform is sold primarily as developer infrastructure (SDKs, MCP servers, CLI) and as a payment gateway service to API merchants.

Product overview

Sponge is a Y Combinator-backed SDK-first wallet and payments platform for AI agents. The product portfolio consists of two core products: Sponge Wallet (agent-owned financial accounts for holding and spending crypto and fiat) and Sponge Gateway (a payment gateway for monetizing APIs to agents via x402 and MPP protocols). These are supported by the Sponge Catalog (API marketplace for agent discovery), MCP servers (for wallet and gateway integration with agent frameworks), and TypeScript/Python SDKs and CLI tools for developers. Sponge Card adds Visa card functionality backed by crypto collateral. The platform enables AI agents to autonomously hold funds, make payments, trade on Hyperliquid and Polymarket, and purchase API services without human intervention.

Differentiator

Problem solved

Functional benefit

Brands

Sponge Wallet: A wallet for AI agents that enables storing stablecoins, issuing virtual cards, accepting ACH/wires, performing trades, and calling x402/MPP endpoints across EVM chains and Solana.
Sponge Gateway
Sponge Catalog

Products and services

Sponge Wallet A wallet for AI agents that enables them to store stablecoins, issue virtual cards, accept ACH/wire transfers, perform trades, and call x402/MPP endpoints. Supports EVM chains (Ethereum, Base), Solana, and Tempo with USDC, ETH, SOL, and pathUSD. Sold to AI agent developers and AI-native companies building autonomous agents.
Sponge Gateway A payment gateway that turns any API into paid endpoints priced and payable by AI agents via x402 or MPP protocols. Supports dynamic pricing rules, OpenAPI import, session billing, and USDC settlement with no code changes required to the upstream API. Sold to API service providers, SaaS merchants, and data providers wanting to monetize APIs to AI agents.
Sponge Catalog A discovery directory (marketplace) of pay-per-use API services that AI agents with Sponge wallets can discover and consume via REST API or agent skill files, enabling autonomous x402 fetch-based purchasing. Sold to API merchants wanting agent-side discovery and to AI agent developers looking for paid services.
Sponge Card A Visa credit card issued by Rain (a Visa Principal Member), powered by digital-asset collateral from the agent's Sponge wallet and funded with USDC. Separate from the crypto wallet and virtual accounts, and accepted anywhere Visa is taken. Sold to AI agent operators and AI-native businesses needing real-world spending for their agents.

Companies that use Sponge

Customer profile

Segments1 record

Ideal customer profiles2 records

Sponge technology and API

Technology

Technology focussed Yes

API detail

Has API: Yes
API docs
API detail

Core technology

AI maturity

App detail

Integration15 records

AI capability2 records

Feature6 records

Sponge partnerships and signals

Strategic signal

Partnerships

Two partnerships are on record, tiered core.

HyperliquidcoreTechnology or IntegrationHyperliquid is a decentralized trading platform (perpetual exchange) with which Sponge is integrated, enabling AI agents to execute trading-related payment flows through Sponge's infrastructure.
PolymarketcoreTechnology or IntegrationPolymarket is a prediction market platform integrated with Sponge, enabling AI agents to make prediction market-related payments through Sponge's payment infrastructure.

Scale indicators1 record

Recent moves7 records

Expansion highlights6 records

Sponge competitors and assessment

Company assessment

Direct peers

Nevermined: Nevermined offers an AI agent payments protocol with agent wallets and pay-per-call API monetization, competing head-to-head with Sponge Gateway and the agent-payment use case on x402-style rails.
Crossmint: Crossmint provides wallet infrastructure, payments, and agentic-commerce APIs for AI agents, including stablecoin wallets and checkout — directly competing with Sponge Wallet and Sponge Gateway across the same AI-agent developer audience.
Skyfire: Skyfire builds payments and identity infrastructure purpose-built for AI agents, letting agents autonomously pay for APIs and services — overlapping directly with Sponge's x402/MPP agent payment offering.
Dynamic: Dynamic offers multi-chain wallet-as-a-service and authentication APIs used by AI and crypto apps; a direct competitor to Sponge Wallet on developer-facing wallet infrastructure.
Privy: Privy provides embedded wallet-as-a-service infrastructure for crypto and AI applications, including agent and consumer use cases — directly competitive with Sponge Wallet's wallet-infrastructure layer.
Thirdweb: Thirdweb provides wallet, payments, and onchain infrastructure for developers across EVM and Solana — comparable to Sponge Wallet on multi-chain wallet tooling and payment integration.

Emerging players

Magic (Magic Labs): Magic provides embedded wallet-as-a-service with passkey and EVM/Solana support used by AI and consumer apps; comparable to Sponge Wallet on developer wallet infrastructure, with growing focus on agent use cases.

Broad incumbents

Circle: Circle issues USDC, the stablecoin that underpins Sponge Wallet balances and Gateway settlement, and is building agentic commerce and CCTP/chain abstractions — a broad incumbent shaping the same payment rails Sponge depends on.
Coinbase Developer Platform (x402): Coinbase developed the x402 protocol that Sponge Gateway uses for autonomous agent HTTP payments; Coinbase's own agent and commerce offerings overlap with Sponge's gateway and merchant-acquiring capabilities.
Stripe (Tempo / Agent Toolkit): Stripe co-developed the MPP/Tempo agent payments protocols that Sponge integrates, and offers its own agent SDK and stablecoin rails — a broad incumbent that is both partner and potential competitor.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights7 records

Customer concentration

Sponge financial estimates

Financial estimate

Revenue estimate

Valuation estimate

Sponge leadership team

Management profile

Number of profiles

Profiles1 record

Sponge funding detail

Funding detail

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

Sponge M&A and investment

M&A and investment

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sponge

What does Sponge do?

Is Sponge a public or private company?

Sponge is a private company. It is classified as venture growth investor backed and is currently operating.

When was Sponge founded?

Sponge was founded in 2024. It employs 1 to 10 people.

Where is Sponge based?

Sponge is headquartered in San Francisco, United States, in the North America region.

How does Sponge make money?

Two revenue lines are on record. Payment Processing (Gateway) is the primary driver. The others are wallet Infrastructure.

Who are Sponge's main competitors?

Direct peers on record are Nevermined, Crossmint, Skyfire, Dynamic, Privy and Thirdweb. Magic (Magic Labs) is listed as an emerging player. Broad incumbents are Circle, Coinbase Developer Platform (x402) and Stripe (Tempo / Agent Toolkit).

Does Sponge have an API?

Yes. Sponge offers a public REST API with endpoints for agent management, wallet operations, transfers, swaps, x402 and MPP payments, cards, banking, and trading integrations. The API uses Bearer token authentication and is documented at docs.paysponge.com with TypeScript and Python SDKs available. MCP (Model Context Protocol) server is available for connecting Sponge wallet tools to agent frameworks. Developer documentation is at docs.paysponge.com.

What industry is Sponge in?

Sponge's product category is AI Agent Payment Infrastructure. Its primary akta.pro industry code is FSADAIAA, Crypto Payment Gateways & Checkout APIs, with a secondary code of FSADACAD, Wallet Infrastructure (SDKs, Wallet-as-a-Service). Its NAICS code is 522320 and its SIC code is 6200.