Frequently Asked Questions

BCkit (Blockchain Kit) is a free, open collection of developer tools for working with Ethereum and EVM-compatible blockchains. It includes a calldata decoder/encoder, a token allowance manager, and Sneak Peek — a tool that lets you connect to any dApp as any address.

Yes. All BCkit tools are completely free with no account required.

BCkit tools work with Ethereum and EVM-compatible chains. The Allowance Manager supports multiple EVM networks. The Decoder works with any EVM calldata regardless of chain. Sneak Peek supports any chain available through WalletConnect.

Only the Allowance Manager requires a wallet connection to view and revoke your token approvals. The Decoder and Sneak Peek work without any wallet connection.

The Decoder lets you paste raw hex calldata (from a transaction) and breaks it down into human-readable function names and parameters. It auto-detects the function signature by looking up the 4-byte selector, so you don't need the ABI.

Calldata is the hex-encoded payload sent with an Ethereum transaction when calling a smart contract function. It contains the function selector (first 4 bytes) followed by the ABI-encoded arguments.

Yes. Enable the "Decode multi-send" option to automatically unpack Safe (Gnosis) multi-send bundles and similar batched transaction formats.

You can manually type the full function signature (e.g. transfer(address,uint256)) into the "Function signature" field. The Decoder will use it to decode the parameters.

Yes. Switch to the Encode tab to construct calldata from a function signature and parameter values.

Lookup lets you search for a 4-byte function selector or event topic and returns known matching signatures from public databases.

It converts between Unix timestamps and human-readable dates — useful when inspecting block timestamps or time-locked contract parameters.

Sneak Peek lets you connect to any dApp as any Ethereum address — without owning the private key. It's useful for exploring what a dApp looks like for a specific wallet, debugging UI flows, or capturing the transactions a dApp would create.

You enter any address (or ENS name) and Sneak Peek creates a mock wallet provider. It supports three connection methods: WalletConnect (paste a WC URI from any dApp), iFrame (load a dApp directly inside Sneak Peek), and a browser Extension.

No. Since you don't have the private key, no transactions are actually signed or broadcast. Sneak Peek captures the unsigned transaction data so you can inspect and decode it.

You can optionally configure your Tenderly API credentials to simulate captured transactions. This shows you the exact state changes, gas usage, and events that would occur if the transaction were executed.

WalletConnect — paste a WC URI from any dApp to connect as the chosen address. iFrame — load a dApp URL directly inside Sneak Peek. Extension — use the Sneak Peek browser extension to inject the mock wallet into any page.

When you approve a dApp to spend your ERC-20 tokens, you create an "allowance" — a permission for that contract to move up to a certain amount of your tokens. Many dApps request unlimited allowances, which remain active even after you stop using the dApp.

Stale or unlimited allowances are a security risk. If an approved contract is compromised or turns malicious, it can drain the approved tokens from your wallet. Regularly reviewing and revoking unnecessary allowances reduces this attack surface.

Connect your wallet in the Allowance Manager, review the list of active approvals, and click revoke on any you no longer need. Revoking sends an on-chain transaction that sets the allowance to zero.

Yes. Revoking an allowance is an on-chain transaction (it calls the token's approve function with a zero amount), so it requires gas.

The Allowance Manager currently supports ERC-20 token approvals.

No. All decoding and encoding happens client-side in your browser. No calldata, addresses, or wallet information is sent to or stored on BCkit servers.

The Allowance Manager only requests read access to view your approvals. Revoking an allowance requires you to confirm each transaction in your wallet. BCkit never asks for your private key or seed phrase.