Approve and Revoke Instructions

Approve grants a delegate the authority to transfer a specific amount of tokens on behalf of the account owner. This enables programmatic token transfers without giving full account control.

We set an "approved" amount, and the delegate can transfer only up to that amount

Revoke removes the current delegate's authority over the account, returning full control to the account owner.

Immediately cancels any existing delegation and only the account owner can revoke delegation (not the delegate itself)

Before we can delegate or revoke any token account, we'll need to already have:

• Initialized a Mint account.
• Initialized a Token account or Associated Token account where we're going to take control of

The amount of tokens we mint are "normalized" for decimals. This means that if we want to mint 1 token that has 6 decimals, we'll need to actually put 1_000_000 as amount

This is how the CPI to the approve() instruction looks like:

approve(
    CpiContext::new(
        ctx.accounts.token_program.to_account_info(),
        Approve {
            to: ctx.accounts.token_account.to_account_info(),
            delegate: ctx.accounts.delegate.to_account_info(),
            authority: ctx.accounts.authority.to_account_info(),
        },
    ),
    &1_000_000,
)?;

And this is how the CPI to the revoke() instruction looks like:

revoke(
    CpiContext::new(
        ctx.accounts.token_program.to_account_info(),
        Revoke {
            pub source: ctx.accounts.token_account.to_account_info(),
            authority: ctx.accounts.authority.to_account_info(),
        },
    ),
)?;