Explorer configuration

set_etherscan

boa.set_etherscan(uri=..., api_key=None, chain_id=1, **retry_options)

Configure the Etherscan client used by boa.from_etherscan() and by Etherscan verification. The default endpoint is Etherscan API v2 and the default chain ID is Ethereum mainnet (1).

The function returns a context-capable setting. Calling it normally keeps the new explorer configuration; using it in a with statement restores the previous configuration on exit.

import boa

boa.set_etherscan(
    api_key="YOUR_ETHERSCAN_API_KEY",
    chain_id=1,
)
token = boa.from_etherscan(
    "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
)

For temporary configuration:

with boa.set_etherscan(
    uri="https://api.etherscan.io/v2/api",
    api_key="YOUR_ETHERSCAN_API_KEY",
    chain_id=1,
):
    token = boa.from_etherscan(
        "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
    )

Supported retry options include num_retries, backoff_ms, and backoff_factor. chain_id must be a positive integer.

from_etherscan

boa.from_etherscan(address, name=None, uri=None, api_key=None, chain_id=None)

Fetch the contract ABI, resolve one proxy implementation layer when reported by the explorer, and return an ABIContract attached to address.

When both uri and api_key are omitted, Titanoboa uses the configured client. Passing either creates a new client: omitted settings use the Etherscan constructor defaults, not the configured client's values. Pass both arguments to retain a custom endpoint and API key; custom retry settings are not carried over.

When chain_id is omitted, Titanoboa uses the active environment's chain ID. The selected client's chain ID is updated before fetching the ABI. When using the configured client, this update persists and also affects subsequent verification through that client.

See Loading contracts for more examples.