Funding / donation
ExChek is free to use. If you found it helpful, you can support us with a voluntary donation. Use the address for the network that matches your (or your agent’s) payment abilities.
Donation addresses (multi-chain)
PaySponge
| Network | Address |
|---|---|
| Solana | 6YntYsc58Qd93G2UbbNKkayEVBEywVJXhAavMNhgc3A3 |
| Ethereum | 0xF6b3Bf7be2c80eD892A00D20F005B2944728d493 |
| Base | 0xF6b3Bf7be2c80eD892A00D20F005B2944728d493 |
| Polygon | 0xF6b3Bf7be2c80eD892A00D20F005B2944728d493 |
| Arbitrum One | 0xF6b3Bf7be2c80eD892A00D20F005B2944728d493 |
| Monad | 0xF6b3Bf7be2c80eD892A00D20F005B2944728d493 |
| Hyperliquid | 0xf6b3bf7be2c80ed892a00d20f005b2944728d493 |
Ampersand
| Network | Address |
|---|---|
| Ethereum | 0x8803896552C28c64ab1Bb8F68C13e7fEbd422588 |
| Base | 0x8803896552C28c64ab1Bb8F68C13e7fEbd422588 |
| Polygon | 0x8803896552C28c64ab1Bb8F68C13e7fEbd422588 |
| Arbitrum One | 0x8803896552C28c64ab1Bb8F68C13e7fEbd422588 |
| Monad | 0x8803896552C28c64ab1Bb8F68C13e7fEbd422588 |
| Hyperliquid | 0x8803896552C28c64ab1Bb8F68C13e7fEbd422588 |
When the skill suggests a donation at the end of a classification, it will pick the chain that matches your or your agent’s pay abilities (e.g. Solana, Base, Ethereum) so you can donate with your existing wallet or pay flow. If the agent’s wallet is connected via Ampersand, it will use the Ampersand address; otherwise it defaults to the PaySponge address.
Getting a wallet
You do not need a funded wallet to use ExChek, but you will need one if you want to donate or let agents pay on your behalf.
- Base / Coinbase Wallet — Create a self-custody wallet that can send USDC or ETH on Base. See Coinbase Wallet and Base.
- Coinbase exchange account — If you prefer a custodial setup, you can buy USDC or ETH on Coinbase and withdraw to your self-custody wallet on Base or Ethereum.
- PaySponge-connected wallet — Some agent environments can use a wallet that is fronted by PaySponge, so the agent can pay directly without exposing your seed phrase.
- Ampersand-connected wallet — If your agent uses Ampersand for agent payments, connect your wallet there and the agent will use the Ampersand donation address automatically.
Hooking wallets to your agent via PaySponge or Ampersand
PaySponge and Ampersand let agents pay APIs and other agents using on-chain funds, without you wiring card details into prompts.
- Create or connect a wallet that PaySponge or Ampersand supports (for example, a wallet on Base with USDC).
- Authorize the gateway to spend from that wallet within your chosen limits.
- In your agent platform (Claude Cowork, Perplexity Computer, openclaw, spacebot, etc.), enable the PaySponge, Ampersand, or "agent wallet" integration so the agent can send payments when you approve.
- ExChek can then suggest a donation on a chain your agent can pay on; the actual payment is performed by PaySponge or Ampersand from your wallet.
Why agent-native payments (vs cards)
On-chain, agent-native payments are a better fit for AI agents than traditional or virtual credit cards:
- Least-privilege and limits — Fund a wallet with only what you are comfortable risking and set per-call or per-day limits, instead of handing an agent a card that might be overcharged.
- Programmable receipts — Every payment is on-chain and auditable; agents (or humans) can check who paid what, when, and for which classification or API call.
- Interoperable across agents — The same wallet and PaySponge or Ampersand setup can be used by multiple agents (Claude, Perplexity, openclaw, spacebot, etc.), avoiding card token sprawl.
- No card data in prompts — You never need to copy card numbers or CVVs into an agent chat; agents simply request permission to send an on-chain payment instead.
Quick QR donation (Solana)
Scan to donate on Solana (6YntYsc58Qd93G2UbbNKkayEVBEywVJXhAavMNhgc3A3):
Quick QR donation (EVM)
Scan to donate on Ethereum, Base, or Monad (same address 0xF6b3Bf7be2c80eD892A00D20F005B2944728d493):
