Decode an EVM smart contract
Decode an EVM smart contract. Pass chain (ethereum, base, polygon, arbitrum, optimism, bsc, avalanche) + address; returns whether the contract is source-verified (Sourcify), its name/compiler/language, whether it is a proxy and its implementation address, and human-readable function and event signatures from the ABI. Optionally pass selector (a 0x 4-byte function selector) to decode what it calls — resolved from the contract's own ABI when verified, otherwise from the public 4byte directory. Pairs with crypto.tx (which gives a `to` address + calldata): turn an opaque contract + selector into "what is this and what does it do." Free, keyless.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://2s.io/api/crypto/contract
| Category | Market data |
|---|---|
| Provider host | 2s.io |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.0045 | 251 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"address": "0xdAC17F958D2ee523a2206206994597C13D831ec7",
"chain": "ethereum",
"selector": "0xa9059cbb"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"properties": {
"method": {
"const": "GET"
},
"queryParams": {
"properties": {
"address": {
"description": "0x contract address.",
"type": "string"
},
"chain": {
"description": "EVM chain (ethereum, base, polygon, \u2026).",
"type": "string"
},
"selector": {
"description": "Optional 0x 4-byte function selector to decode.",
"type": "string"
}
},
"required": [
"chain",
"address"
]
},
"type": {
"const": "http"
}
},
"required": [
"type",
"method",
"queryParams"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}