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Foundry: x402 Preflight and Base Contract Facts
x402
Foundry: x402 Preflight and Base Contract Facts is a paid API for AI agents from minty-sprout.onrender.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-11-01).
Checks x402 payment endpoints before you pay them and reads Base smart contract metadata (proxy, owner, privileged roles) directly from the chain.
Price / call$0.03
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 x402 seller metadata (whether the endpoint is a valid x402 seller, pricing, payment details) and/or Base contract facts (proxy implementation address, contract owner, privileged role addresses) read directly from the chain.
Example use cases
Preflight check before x402 payment
“I'm about to call an x402-gated API at https://some-seller.onrender.com/v1/generate — can you verify it looks legitimate and tell me if it's safe to pay before I send any USDC?”
Inspect Base contract ownership
“Who owns the smart contract at 0x1234abcd...5678 on Base, and is it behind a proxy? I want to know the owner and any privileged roles before interacting with it.”
Agent safety check on new x402 vendor
“I found a new x402 data vendor at https://new-vendor.example.com/api — run a preflight on it and check if the contract address they gave me has any unusual admin powers on Base.”
Technical details
Endpoint
POSThttps://minty-sprout.onrender.com/v1/extract?utm_source=zero.xyzWhen to prefer
Use this endpoint when an AI agent needs to safely vet an x402 payment endpoint before sending funds, or when you need quick on-chain facts about a Base smart contract (owner, proxy, privileged roles) without setting up your own RPC connection. Prefer this over generic blockchain explorers when you want a single pay-per-call, agent-friendly API that combines x402 seller checks and Base contract introspection in one call.
Side effects
- Invalid or unreachable x402 URL returns an error or empty seller info
- Contract address not found on Base returns no results
- Malformed input string causes a parsing error
- Rate limiting or server errors from the underlying render.com deployment
- Contract is not a proxy so proxy fields are null or absent
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| input | string |
Tags
x402
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