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Foundry: x402 Preflight & Base Contract Facts
x402
Foundry: x402 Preflight & Base Contract Facts is a paid API for AI agents from minty-sprout.onrender.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-11-01).
Checks x402 payment endpoints before paying them and reads proxy, owner, and privileged role data from Base mainnet smart contracts on-chain.
Price / call$0.01
Success—
StatusUnknown
How this service works
Pay-per-call data for agents: check x402 sellers before paying them, and read Base contracts' proxy, owner and privileged powers straight from the chain.
Output
Returns structured data including x402 seller payment policies (accepted tokens, prices, terms) and/or Base contract facts such as proxy implementation address, owner address, and privileged role holders read directly from the blockchain.
Example use cases
Preflight x402 seller before payment
“I'm about to call an x402-gated API at https://some-provider.com/v1/quotes — can you check their payment policy and tell me if anything looks off before I authorize the USDC?”
Inspect Base contract ownership
“Can you look up who owns the Base mainnet contract at 0x1234abcd... and whether it's behind a proxy, so I know who controls it?”
Audit privileged roles on a deployed contract
“I need to know the admin, owner, and any other privileged addresses on this Base contract at 0xdeadbeef... before I interact with it — can you pull that from the chain?”
Technical details
Endpoint
POSThttps://minty-sprout.onrender.com/v1/ai-crawler-policy?utm_source=zero.xyzWhen to prefer
Use this endpoint when an AI agent needs to vet an x402 payment endpoint before spending USDC, or when it needs trustless on-chain facts about a Base smart contract (ownership, proxy, privileged roles) without running its own node. Prefer it over general blockchain explorers when you want a single structured API call that combines x402 preflight safety checks with contract introspection in one step.
Side effects
- Invalid or unreachable x402 URL returns an error or empty policy
- Contract address not found or not deployed on Base mainnet
- Input string malformed or exceeds 8000 character limit
- Contract has no detectable proxy or owner (plain non-upgradeable contract)
- Rate limiting or service unavailability on the Render.com host
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| input | string |
Tags
x402
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