Farcaster

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FAQ ​

Signatures ​

How do I generate an EIP-712 signature? ​

See the contract reference docs for documentation on each EIP-712 signature, including Typescript code examples.

If you're using Typescript/JS, the @farcaster/hub-web package includes tools for generating and working with EIP-712 signatures. To ensure you're using the correct addresses and typehashes, we recommend importing the ABIs and EIP-712 types from the contracts module or using the provided Eip712Signer helper.

See the "Working with EIP-712 signatures" example app in the hub monorepo for a reference that demonstrates each signature and contract call.

How can I debug an invalid EIP-712 signature? ​

To help debug EIP-712 signing, every contract that uses EIP-712 signatures exposes its domain separator and typehashes as constants along with a hashTypedDataV4 helper view. If you're constructing signatures in Solidity or another low level language, you can use these to help debug.

Reference ​

Where is the full contract source code? ​

The contracts repo is on Github here.

Where do I get contract ABIs? ​

Find contract ABIs and deployment addresses here.

Where can I find audit reports? ​

Past audit reports are linked from the contracts repo.

Are the Farcaster contracts deployed to a testnet? ​

No. Consider using network forking to test or develop against the OP mainnet contracts.

Data ​

How do I find a user’s custody address? ​

Call the custodyOf function on the IdRegistry.

How do I find a user’s recovery address? ​

Call the recoveryOf function on the IdRegistry.

How do I find an account’s fid? ​

Call the idOf function on the IdRegistry.

How do I look up the account keys for my fid? ​

Call the keysOf function on the KeyRegistry.

Other ​

What is an app fid? How do I get one? ​

An "app fid" is no different than any other Farcaster ID: it just represents an application rather than an individual user. You can register an app fid directly through the Bundler or IdGateway, or use a Farcaster client to register an account for your app. Since you'll need to sign key request metadata from the wallet that owns your app fid, keep the private key secure.