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x402 Calldata Safety Decoder
x402
x402 Calldata Safety Decoder is a paid API for AI agents from x402-services-production.up.railway.app, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).
Decodes raw EVM calldata into its function name and arguments, and flags dangerous transaction patterns like unlimited approvals, setApprovalForAll, permit, and transferFrom.
Price / call$0.05
Success—
StatusUnknown
How this service works
Decode raw calldata into its function + arguments and flag dangerous patterns (unlimited approve, setApprovalForAll, permit, transferFrom). Send { data }. Understand what a transaction actually does before signing.
Output
Returns the decoded function name and its parsed arguments from the raw calldata, along with boolean or labeled flags indicating whether the transaction contains dangerous patterns such as unlimited ERC-20 approve, setApprovalForAll, permit signatures, or transferFrom calls — helping the user understand what a transaction actually does before signing it.
Example use cases
Example prompt
“Before I sign this transaction, can you decode this calldata and tell me if it contains anything dangerous like an unlimited approval or setApprovalForAll? Here's the data: 0x095ea7b3000000000000000000000000deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef000000000000000000000000000000000000000000000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff”
Technical details
Endpoint
POSThttps://x402-services-production.up.railway.app/api/safety/decodeWhen to prefer
Use this endpoint when you need to understand what an EVM transaction actually does before signing it — especially when the calldata is opaque hex and you want to detect dangerous approval patterns. Ideal for wallet security checks, DeFi transaction review, phishing detection, and any agentic flow that needs to gate on transaction safety before proceeding.
Side effects
- Invalid or malformed calldata returns a parse error
- Unrecognized function selector (not in ABI registry) may return partial decode or unknown function name
- Empty or missing 'data' field returns a 400 validation error
- Very short calldata (less than 4 bytes) cannot identify a function selector
- Network timeout or service unavailability returns 5xx error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| datarequired | string | 0x calldata blob |
Tags
x402
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