Companies want AI agents to pay suppliers, but an LLM holding a wallet can be talked into paying a fraudster ("our bank details changed") or loop on a bug. Aegis Vault moves accounts-payable controls on-chain so the agent never holds a key that can move money. A Rust vault contract holds the funds and checks every agent payment request: duplicate invoice, vendor allowlist, hard per-payment cap, velocity limit, then approval threshold and daily budget (held for the CFO) or pay. Blocked attempts are recorded on-chain with a reason, giving an audit trail of what a compromised agent tried. NEAR makes this work natively: the agent account's full-access key is deleted and it keeps only a function-call access key that can call request_spend on the vault, so a stolen agent key can't transfer, approve or touch anything else. Decisions are NEP-297 events, vendors are named accounts, and a rule-based explainer turns each rule into a CFO-readable reason. Live on testnet with a public dashboard, near-workspaces sandbox tests, a prompt-injected agent demo and an attacker script.
Loops House