AttestCaster

AttestCaster is an attestation builder app that serves as an alternative client for Farcaster. It leverages Sign Protocol to issue attestations regarding the validity of casts made in Farcaster.

For the initial release, it will only be available to admins/mods of the various channels on Farcaster.

We built AttestCaster during this hackathon. AttestCaster is an attestation builder app that serves as an alternative client for Farcaster. It leverages the Sign Protocol to issue attestations regarding the validity of casts made on Farcaster.

The app is built with React, Next.js, Node.js, viem, and the SDKs of Farcaster and Sign Protocol.

An attestation is the act of confirming and certifying the validity of a claim or assertion, such as a statement, event, or even a legal document. This provides support for an assessor (a.k.a., verifier) to confidently accept or reject a given claim that they are presented with.

What we learned during the process:

We learned how the Sign Protocol works and how to use their SDKs to access their services. We learned how to use OnchainKit (built by Coinbase) and deployed it on Vercel. We learned how to access Farcaster through their APIs, especially since there are different API providers. Challenges:

To access a Farcaster's cast, both FID and cast hash are required. Also, to get the cast hash and FID from a URL, multiple calls are needed if we use Hubble to access Farcaster. It takes some time to design and match the schema with Farcaster and Frames' API. Typescript format checking wasted some time. Use FID instead of an address to attest the cast (work in progress). Etc.