How to Build a Farcaster Frame that Mints NFTs

[@MrZozord]

Thanks a lot for this amazing tutorial ! Silly question : In order for our frame to be ''live'' on Farcaster (for it to be casted) we just need to include the url inside our cast and Farcaster will detect that it's a frame and display the response of that url ?

[@pinatacloud]

No problem! :) All you have to do is paste the url in the frame and it will pick it up! Might be helpful to test in the validator warpcast.com/~/developers/frames

[@codebushi]

Thanks for the great tutorial! One question I had: on the Farcaster docs, it suggests not using "body.untrustedData" since it can be spoofed. Is there a way to use the "/v1/validateMessage" endpoint and pull from "body.trustedData"? It doesn't seem like the Pinata Hub API has this documented.

[@pinatacloud]

No problem! You can actually do this inside the FDK docs.pinata.cloud/farcaster/fdk#validateframemessage

[@adrian2928]

Great tutorial, have built out an amazing frame to mint NFTs thanks to you :) However, with this method (using "balanceOf") people can just transer the NFT to a different address and mint another one. Is it possible to have some sort of "hasEverOwned" function instead that checks the addresses full transaction history?

[@pinatacloud]

Glad you enjoyed it! :) You could probably make a change in the smart contract to make a mapping of everyone who has minted to prevent that, however it doesn’t necessarily stop them from using another account / wallet. You might have to be creative depending on your use case!

[@adrian2928]

@@pinatacloud thanks mate, great tip. Was going about it backwards trying to use the alchemy API to trace transaction data. Got it to work first try using the contract mapping. Thanks again and keep up the great tutorials!

[@mansijoshi2574]

Hey. Calling post api of mint nft is working fine. But when I check that contract address in base scan I am not able to see the token which should minted into wallet. BTW great tutorial. Thank you.

[@pinatacloud]

Thank you! 🙏🏻 It sounds like it could be a few things. One of them that happens a lot is differing env variables, so one might be in dev but a different one in Vercel/prod. If you’re willing to debug a bit feel free to email us! [e-mail]

[@mansijoshi2574]

Yup. Got it. Thanks a lot.@@pinatacloud

[@HugoMartiMusic]

i am getting "Error: private key must be 32 bytes, hex or bigint, not string" even putting 0x in front at the .env.local. any idea what could be wrong?

[@pinatacloud]

I would start with console logging the env variable itself to make sure it’s getting processed in the code then go from there!

[@knowwhatiswhat4276]

🥂🔷

[@onyx_dev]

Pls who else is getting this error with viem package, "Error: private key must be 32 bytes, hex or not string at normPrivateKeyTo Scaler😢

[@pinatacloud]

Hey there! You might need to add 0x in front of the private key inside .env.local file!

[@onyx_dev]

@@pinatacloud it solved it 😄, Thank you.