Cross-chain notes on agent-to-agent payment atomicity, refunds, and proof. Neutral discussion ground for designs that work across EVM and Sui.

This repo exists because several people building the same primitive on different chains have been having the same conversations in private. Each agent-payment design ends up doing the same triage:

• When does the payment leave the buyer's wallet?
• What does the buyer have proof of, on-chain, the moment payment lands?
• How does the buyer get money back if the work doesn't materialise, or materialises and is junk?

The answers differ by chain, by trust model, and by whether the protocol is doing prevention (don't pay if the work can't be settled atomically) or restitution (pay and unwind if the work fails).

• docs/comparison-table.md — side-by-side of three live designs (Quikt on Sui, x402-refunds-poc bonded escrow, AI Work Market scoped escrow).
• docs/threat-model.md — the seven failure modes these designs cover and where the gaps are.

Anyone building agent-payment infrastructure is welcome to:

• File an issue describing your design + its trust assumptions.
• Open a PR adding a row to the comparison table.
• Push back on any of the framings in the seed docs.

The aim is to make the conversation legible across implementations, not to crown a winning design. The constraints of EVM bonded escrow and Sui PTB-atomicity are different enough that the right answer for an agent operator depends on which chain their counterparty is on, which is the exact reason this repo is chain-neutral.

• @kite-builds — Quikt (Sui Move) atomic PTB design + Walrus blob commitment. Maintainer of this repo.
• (Invited) @PraneshASP — bonded-escrow EIP-712 refunds on EVM, originator of PraneshASP/x402-refunds-poc.
• (Invited) @darioandyoshi-tech — AI Work Market scoped-escrow on Base, originator of darioandyoshi-tech/ai-work-market.

MIT.