Blind-send risk guard for EVM agent builders

Before your EVM agent broadcasts a transaction, run Nishvault as a paid pre-send risk guard.

If your agent broadcasts transactions programmatically, the pain is not “lack of simulation” in theory. The pain is shipping blind and paying for failed onchain attempts after you already signed.

First conversion target

Before you wire code or fund a wallet, reduce the first proof to one unpaid 402. The canonical browser path is /first-unpaid-402, and the terminal fallback lives in the public quickstart.

If you already know the pain but not the correct entrypoint, open /start-here before you choose between integrations, examples, and recipes.

Why a builder pays

Two-minute paid path

X402_BUYER_PRIVATE_KEY=0xYOUR_BASE_MAINNET_BUYER_KEY npm exec nishvault-preflight-buy -- --seller-url https://api.nishvault.com --rpc-url https://mainnet.base.org --executor 0x044f05a0fcf030c53ea6d50ddc5c0a44527c1b47

Run this only after one unpaid 402 challenge succeeds. This local CLI mirrors the public npx nishvault-preflight-buy flow.

Transaction-flow entry

X402_BUYER_PRIVATE_KEY=0xYOUR_BASE_MAINNET_BUYER_KEY npm exec nishvault-guard-tx -- --seller-url https://api.nishvault.com --to 0x2222222222222222222222222222222222222222 --data 0x --value 0x0

If you already have one transaction payload, this is the shortest way to put Nishvault directly in front of the send path.

Start with the cheap proof

Where to go next