Reverse a 4-byte function selector or 32-byte event topic into its signature fro...
https://saylorinnovations.com/api/chain/signature-lookupOverview
Reverse a 4-byte function selector or 32-byte event topic into its signature from a built-in list of 120 common token, NFT, DEX and lending signatures.
Protocol
x402
Price
$0.01
Payment Asset
USD Coin
Payment Network
eip155:8453
Category
crypto/nft
Provider
Saylor Innovations Data Desk
Source
bazaar
Indexed
2026-10-21 04:24:46
Health
Status
healthy
Latency (p50)
413ms
Uptime (30d)
100.0%
Reliability Score
95/100
Last Checked
2026-10-28 15:23:35
Last Healthy
2026-10-28 15:23:35
Consecutive Failures
0
x402 Payment Validation
Payment Requirements
Valid
Asset Verified
Known USDC
Facilitator
—
Input Schema
{
"method": "GET",
"queryParams": {
"hash": "0x095ea7b3"
},
"type": "http"
}
Output Schema
{
"example": {
"database_size": 120,
"found": true,
"hash": "0x095ea7b3",
"kind": "function selector (4 bytes)",
"matches": [
{
"kind": "function",
"signature": "approve(address,uint256)"
}
],
"note": "Matched against a built-in list of common token, NFT, DEX, lending, proxy, Safe and ENS signatures. Several signatures can share a 4-byte selector, so confirm against the contract.",
"source": "Built-in signature list (computed locally with keccak256)"
},
"type": "json"
}
Recent Health Checks
| Time | Status | HTTP | Latency | Error |
|---|---|---|---|---|
| 2026-10-28 15:23:35 | healthy | 402 | 413ms | |
| 2026-10-28 14:18:14 | healthy | 402 | 398ms | |
| 2026-10-28 05:43:53 | healthy | 402 | 449ms | |
| 2026-10-28 04:45:56 | healthy | 402 | 337ms | |
| 2026-10-28 03:52:06 | healthy | 402 | 329ms | |
| 2026-10-28 02:52:54 | healthy | 402 | 372ms | |
| 2026-10-28 01:48:17 | healthy | 402 | 468ms | |
| 2026-10-28 00:41:29 | healthy | 402 | 356ms | |
| 2026-10-27 23:45:10 | healthy | 402 | 1233ms | |
| 2026-10-27 22:59:02 | healthy | 402 | 311ms | |
| 2026-10-27 21:47:56 | healthy | 402 | 1606ms | |
| 2026-10-27 20:33:09 | healthy | 402 | 442ms | |
| 2026-10-27 19:28:31 | healthy | 402 | 322ms | |
| 2026-10-26 19:54:23 | healthy | 402 | 1072ms | |
| 2026-10-26 04:57:25 | healthy | 402 | 572ms |