I'm trying to make a program that's able to get mint authorization on a PDA (first function), and then mint tokens using that authorization. My transfer authorization function works fine (tested on devnet), but I can't get the mint to work. I keep getting "Cross-program invocation with unauthorized signer or writable account." error.

On most of the exemples for a minting function, the mint (the token) is created by the program. Here that's not the case. I guess I'm doing something wrong there?

Also, I'm forced to clone another_authority so I don't do a mutable and immutable borrow in the same scope. Is it wrong?

2 Answers 2


Your seeds in the second method is different from the first, you forgot to add the b"autho" prefix. Make the following change and your code is good to go:

 let seeds: &[&[u8]] = &[
     b"autho",                          // Seed 0: autho PREFIX
     another_authority.admin.as_ref(),  // Seed 1: Admin's public key
     bump_seed,                         // Seed 2: Bump nonce

 let signer_seeds = &[&seeds[..]];

  • Indeed, it now works. Thanks a lot! Commented Jan 2 at 15:59
  • Great! If it worked, you can accept the answer to close the question.
    – 0xShuk
    Commented Jan 2 at 16:03

Just at quick glance, it looks like you are not passing in all your seeds in your minting function. Specifically, I think you need to add b"autho" into your seeds declaration.

Here's an example similar to yours: https://github.com/solana-developers/program-examples/blob/d6cd69d8df3eb95966b3d2361ede84529413567a/tokens/pda-mint-authority/anchor/programs/token-minter/src/instructions/mint.rs#L46

FYI you can also use the seeds constraint in your Minting struct to help ensure you're passing a valid PDA (it's not limited to use only with init).

  • Indeed, it now works. Thanks a lot! Commented Jan 2 at 15:59

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