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Add a Crypto Donation Button to Any Site (MIT Widget)
One script tag adds a donate button and a live 'shelters received' meter to any page or web game. The widget is MIT licensed, has no dependencies, and never holds the gift.
6 min read
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Open-source shelter payouts for developers
For developers: the open-source (MIT) ShelterSplit and DonateRouter contracts behind every Token Tails shelter payout, EIP-3009 gifts, USDC payouts on Arc and other networks, and the Shelter Rail SDK you can drop into your own app.
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AI Agent Spending Limits On-Chain: A Capped USDC Contract
The safest spending limit for an AI agent is one the chain enforces, not the prompt. CappedSpender is a small MIT contract that caps every gift and every day, and can only pay a shelter split.
6 min read
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eth_getLogs Block Range Limits: Index Payouts Safely
Public RPCs refuse eth_getLogs ranges above their limit instead of trimming them. Field notes from the indexer behind a live, seven-chain donation ledger: windows, cursors, dedupe and honest totals.
6 min read
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x402 Donations: Let an AI Agent Pay a Shelter Over HTTP
x402 turns HTTP 402 Payment Required into a payment step an AI agent can complete on its own. Here is how we point it at a cat shelter's wallet, with open code and an honest status.
6 min read
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EIP-3009 Gasless USDC Donations: receiveWithAuthorization
A donation-focused guide to EIP-3009: the signed USDC authorization, why a contract payee needs receiveWithAuthorization, how an MIT router binds the payout list into the nonce, and what trips people up.
6 min read
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USDC Payment Splitter Contract: How ShelterSplit Works
ShelterSplit is a pass-through USDC splitter used in production to pay a cat shelter. Here is the design, the code that matters, and how to deploy your own.
5 min read
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USDC Payouts on Arc: Field Notes From a Live Shelter Split
What we learned running real shelter payouts on Arc: USDC as gas, the decimals trap, deploying with Foundry, indexing payouts for a public page, and what a treat costs.
5 min read