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Crypto Calldata Decoder & Risk Analyzer (x402)
x402
Crypto Calldata Decoder & Risk Analyzer (x402) is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).
Decodes raw EVM calldata or a Base transaction hash into human-readable function calls with risk assessment, flags, and guidance.
Price / call$0.002
Success—
StatusUnknown
How this service works
Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.
Output
Returns decoded function name, selector, ABI-typed arguments with values, risk verdict (e.g. CAUTION/OK), risk level (low/medium/high), flags like 'unlimited_approval', a plain-English summary of what the transaction does, spender label if known, and guidance on next steps.
Example use cases
Pre-signing approval risk check
“Before I sign this transaction, decode this calldata and tell me what it's approving and whether it's risky: 0x095ea7b3000000000000000000000000000000000022d473030f116ddee9f6b43ac78ba3ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff on contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.”
Decode on-chain transaction by hash
“Can you decode Base transaction 0x4a3b2c1d... and tell me what function was called, what the arguments were, and whether there are any red flags I should know about?”
Identify unlimited token approval
“I just saw a wallet pop up asking me to approve something — the calldata is 0x095ea7b3 followed by a bunch of hex. Decode it and tell me if it's granting unlimited token access to some contract, and if so what contract.”
Technical details
Endpoint
GEThttps://kr-x402-mvp.kgy5612.workers.dev/crypto/decode?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an AI agent or user needs to understand what a raw EVM transaction or calldata blob actually does before signing — especially for risk assessment of token approvals, DeFi interactions, or any unknown contract call on Base. Prefer over generic ABI decoders when you also need risk verdicts, spender labels, and plain-English guidance bundled in one pay-per-call response with no API key setup.
Side effects
- Missing or malformed calldata hex returns validation error
- Unknown function selector yields partial decode with signature_source: unknown
- Invalid Base tx hash returns not-found or RPC error
- Calldata too short (under 4 bytes) cannot be decoded
- Payment failure via x402 if USDC balance insufficient
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"args": [
{
"type": "address",
"value": "0x000000000022D473030F116dDEE9F6B43aC78BA3"
},
{
"type": "uint256",
"value": "115792089237316195423570985008687907853269984665640564039457584007913129639935"
}
],
"risk": "medium",
"chain": "base",
"flags": [
"unlimited_approval"
],
"amount": "unlimited",
"spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3",
"summary": "lets Uniswap Permit2 move ALL USDC from the signer",
"verdict": "CAUTION",
"function": "approve(address,uint256)",
"guidance": "Review the decoded args; simulate with /crypto/base-rpc?method=eth_call before signing.",
"selector": "0x095ea7b3",
"unlimited": true,
"spender_label": "Uniswap Permit2",
"signature_source": "builtin"
}
}Tags
x402
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