Function parse_driver_message 

pub fn parse_driver_message(
    value: &Value,
    limits: &Limits,
) -> Result<(), ParseError>

Validate one driver → adapter message.

Driver traffic is read tolerantly: unknown fields in the envelope and in the driver’s nested objects (marker, logs, limits) are ignored and passed through to the caller, so a newer driver can add a field without breaking an adapter published before it existed.

The asymmetry is about who is speaking, not about the message: adapter traffic crosses an untrusted boundary, where an unknown field is a signal rather than an extension. Tolerance is not leniency either — known fields keep their types, and the closed sets (message types, error codes, subscribe, roles, actions) stay closed in both directions.

Errors

Returns a ParseError whose code is bad-version, malformed or limit-exceeded.