Sponge

• Name: Sponge
• URL: https://paysponge.com/
• Category: agent wallet and payments infrastructure / x402-MPP gateway / wallet-control-plane for AI agents
• Tags: ethereum-ecosystem solana-ecosystem
• Summary: Sponge is an agent wallet control plane with x402/MPP support attached. The durable part is agent provisioning, API-keyed wallet control, and gateway monetization around those wallets — not the idea that it is a new payment rail.
• What it does:
  • Gives individual agents wallet identities and API-key-based access for balances, transfers, swaps, bridging, and multi-chain wallet operations across Ethereum, Base, Tempo, and Solana
  • Provides two distinct SDK/control layers: SpongeWallet for runtime agent actions and SpongePlatform for fleet provisioning, agent creation, and key rotation using master keys
  • Supports non-interactive agent API keys, interactive device-flow login, and locally cached credentials for CLI/SDK use
  • Exposes paid-request tooling for x402 and MPP so agents can pay for APIs and other services directly from their wallets, including Tempo-native MPP flows
  • Includes Sponge Gateway, which sits in front of an upstream API and lets operators price and meter endpoints without changing the upstream code, then expose them to agents through x402 or MPP
  • Ships agent-facing integration surfaces including MCP, CLI, SDK docs, OpenAPI specs, and explicit setup paths for clients like Claude, ChatGPT, Codex, Cursor, and OpenClaw-style agent workflows
  • Also exposes fiat onramp session endpoints and trading / transfer APIs, suggesting a broader operational wallet surface than the homepage alone implies
• Key claims:
  • The homepage frames Sponge as “the easiest way for agents to hold and spend money, and for businesses to sell directly to them”
  • The docs position Sponge as infrastructure for “wallets for transfers, swaps, bridges, Hyperliquid trading, and x402 and MPP payments across EVM and Solana”
  • The authentication docs make an important architecture distinction between agent-scoped API keys and user-level master keys that can create and manage many agents
  • The Gateway docs explicitly market a no-code upstream monetization layer: “Turn any API into paid endpoints, priced, metered, and payable by agents, with no code changes to your upstream.”
  • The llms.txt index and OpenAPI exposure reveal a much larger operating surface than a normal wallet page: agent CRUD, onramp sessions, paid fetch flows, trading, bridges, transaction history, and wallet details
  • The public GitHub organization reinforces the product shape with repos for the SDK, docs, wallet skills, and x402 / Tempo-oriented tooling
• Whitepaper: No canonical standalone Sponge whitepaper or litepaper surfaced in this pass. The strongest current sources of truth are the official site, docs, llms.txt index, Gateway docs, authentication docs, payments quickstarts, OpenAPI specs, and public GitHub org / SDK repo; see ../whitepapers/sponge-primary-sources-2026-04-28.md.
• Sources:
  • https://paysponge.com/
  • https://docs.paysponge.com/
  • https://docs.paysponge.com/llms.txt
  • https://docs.paysponge.com/authentication
  • https://docs.paysponge.com/gateway
  • https://docs.paysponge.com/quickstart-payments
  • https://github.com/paysponge
  • https://github.com/paysponge/paysponge-sdk

Internal linkages

• Keep this note on the strongest upward reads: x402, agent-payments-protocol, and open-payments.

Control surface

• The leverage sits in agent provisioning, API-key issuance, wallet custody boundaries, gateway metering, and which rails or chains the operator exposes behind one runtime-facing surface.

• That is real wallet-and-gateway power, but it is still a hosted control plane layered above stronger payment and authorization standards.

• Keep the note centered on those operator defaults instead of inflating it into a new rail.

• Last reviewed: 2026-06-04 UTC