Implementing Custom Errors in Precompiles

integration

How to create a Maroo precompile that returns structured Solidity errors.

Embed the Common Precompile

Ensure your precompile struct embeds maroo/precompiles/common.Precompile instead of the standard cosmos-sdk precompile struct. This activates the custom error handling logic.

import "github.com/maroo-network/maroo/precompiles/common"

type MyPrecompile struct {
    common.Precompile
}

Return RevertWithData

When an error occurs, ABI-encode your error arguments and wrap them in RevertWithData.

func (p *MyPrecompile) SomeMethod(...) ([]byte, error) {
    // ... logic ...
    if unauthorized {
        // Pack the Solidity error: error Unauthorized(address user)
        packed, _ := p.ABI.Errors["Unauthorized"].Inputs.Pack(userAddr)
        selector := p.ABI.Errors["Unauthorized"].ID
        data := append(selector[:], packed...)
        
        return nil, &common.RevertWithData{Data: data}
    }
    return result, nil
}