What is the Farcaster fee?

Paid to the Farcaster protocol. Every user on Farcaster has to pay for at least unit of storage to be able to cast and react to content.

What is the transaction fee?

Paid to the OP Mainnet blockchain for the onchain transaction, i.e. gas fees.

What is the payment fee?

Paid to the app store on your mobile device.

What is the Warpcast fee?

Paid to Warpcast. Warpcast assumes some amount risk when conducting onchain transactions. The remainder is kept as revenue for Warpcast. Warpcast is free to use otherwise.