`provekit/backend/bn254/src/frontend/witness_generator`: serializes the ABI as a json string. Something like CBOR might be better.

On 2026-07-06 in 05de18e “Merge pull request #458 from worldfnd/sl/goldilocks-field-abstraction”:

serializes the ABI as a json string. Something like CBOR might be better.

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct NoirWitnessGenerator {
    // Note: Abi uses an [internally tagged] enum format in Serde, which is not compatible
    // with some schemaless formats like Postcard.
    // [internally-tagged]: https://serde.rs/enum-representations.html
    // TODO: serializes the ABI as a json string. Something like CBOR might be better.
    #[serde(with = "serde_jsonify")]
    pub abi: Abi,

    /// ACIR witness index to R1CS witness index
    /// Index zero is reserved for constant one, so we can use `NonZeroU32`

From provekit/backend/bn254/src/frontend/witness_generator.rs:15

Start in provekit/backend/bn254/src/frontend/witness_generator.rs at the NoirWitnessGenerator abi field and read the serde_jsonify handling. Review the ABI's internally tagged enum constraint and the surrounding serialization setup before deciding whether an alternative format is suitable. Done means the ABI no longer relies on a JSON string and the chosen representation preserves the required serialization and deserialization behavior.