Bytecode of a contract

Open the contract on its entity page →

The current runtime bytecode of a contract as hex, with its code hash and a structural fingerprint that is equal across contracts sharing the same logic.

GET https://tracefast.xyz/api/v1/chains/1/contracts/{address}/bytecode

Parameter	In	Type	Notes
`address`	path	string	`0x`-prefixed, 40 hex characters, any case

Access — an API key on the Enriched Data plan or higher (plans), or no key at all: pay per call with x402 at the same path on https://mpp.tracefast.xyz/api/v1, at the price its 402 states. As a tool for AI agents: get_contract_bytecode on the MCP server. Stable — see stability.

chains/1 is a literal: other chain ids answer 404 chain_not_supported. The method takes no query parameters — an unknown one is refused rather than ignored.

What it covers, and what it does not

Runtime code, current state. This is the code stored at the address now — not the creation code, and not earlier versions. When the code changed, the contract method says so in lifecycle.
Up to 24 576 bytes of code, the EVM's contract size limit — at most 49 154 characters of hex.
codeHash and fingerprint answer different questions. Two contracts with equal codeHash have byte-identical code. Two with equal fingerprint share their logic even when their compiler metadata differs.
An address with no indexed code answers 404.

Response

200 application/json, WETH. The bytecode value is shortened here; the real one is 6 250 characters:

{
  "data": {
    "chainId": 1,
    "address": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
    "codeHash": "0xd0a06b12ac47863b5c7be4185c2deaad1c61557033f56c7d4ea74429cbb25e23",
    "bytecode": "0x6060604052600436106100af576000357c0100…",
    "bytecodeSize": 3124,
    "fingerprint": "0xc58b77064884ea1d696b177387c2300f3a12e58857ed2a07e588d8543f8f2a89"
  },
  "meta": {
    "chain": "ethereum",
    "timestamp": 1789047628707,
    "cached": false,
    "docs": "https://docs.tracefast.xyz/api/contract-bytecode"
  }
}

`data`

Field	Meaning
`chainId`	`1` — Ethereum mainnet
`address`	the contract, lowercase
`codeHash`	Keccak-256 hash of the code
`bytecode`	the runtime code, `0x`-prefixed hex. Empty when the code for this hash is not available — `codeHash` and `bytecodeSize` are still stated
`bytecodeSize`	size of the code in bytes: half the hex length, without `0x`
`fingerprint`	a structural fingerprint of the code, stable across metadata-only differences. Equal fingerprints mean shared logic

What the bytecode is and how the EVM runs it: ethereum.org — the EVM.

Errors

Status	`code`	When	`details`
404	`not_found`	no contract code is indexed at this address	—
422	`block_not_available`	`reason: coverage_gap` — recent blocks are in a coverage gap, and a contract deployed in them cannot be seen right now. Retry later	`coverageGapFromBlock`, `coverageGapToBlock`, `maxAvailableBlock`

Malformed input, unknown parameters and the key check's 401/403/429 are the same for every method — see conventions and API keys.

One contract — the code's interfaces, proxy pattern and lifecycle
Function selectors of a contract — the functions found in this code
Implementations of a proxy contract — where a proxy's real logic lives
Contracts on the entity page — the same contract, read in the app

Last updated 22 Oct 2026, 08:06 UTC · verified against TraceFast v1.0.261 · Markdown

Bytecode of a contract

What it covers, and what it does not

Response

data

Errors

Related pages

`data`