MutationCodec

Bridges a specific mutation shape (one NetworkEndpoint implementation + body type) to and from a JSON string, so it can survive in a durable MutationStore and be replayed after the process restarts.

Kenwork can't do this generically: NetworkEndpoint implementations are consumer-defined types (typically a data class/object per route — see the cookbook), so only the consumer knows how to serialize and reconstruct them. Implement one MutationCodec per mutation "shape" you want to survive process death, e.g.:

object LikeVideoCodec : MutationCodec<Unit> {
    override val id = "like-video"
    override fun encode(endpoint: NetworkEndpoint, body: Unit?): String =
        Json.encodeToString(LikeVideoPayload((endpoint as LikeVideo).videoId))
    override fun decode(payload: String): DecodedMutation<Unit> {
        val decoded = Json.decodeFromString<LikeVideoPayload>(payload)
        return DecodedMutation(LikeVideo(decoded.videoId), null, null)
    }
}

id must be stable across app versions/releases — it's persisted in every MutationRecord this codec produces and is how MutationQueue.restore finds the codec to decode a record after relaunch. Register codecs via the MutationQueue constructor (or implicitly the first time you enqueue with one) so they're available before MutationQueue.restore runs.

Pass codec = null to MutationQueue.enqueue for mutations you don't need to survive a process death — they still get retry + coalescing, just no persistence.