compact-core:compact-circuit-costs

To optimize Compact circuit costs, minimize gate counts by bounding loop unrolling, choosing transientHash over persistentHash where state persistence is unnecessary, and structuring maps and sealed fields to limit ledger writes.

The Midnight Compact circuit cost model spans three dimensions: circuit and proving costs driven by gate counts, runtime gas costs for execution, and state costs arising from ledger interactions and persistent writes.

Use transientHash in Compact contracts when data does not require long-term ledger state persistence, which reduces state costs and circuit size; prefer persistentHash only when state survival across transactions is mandatory.

Loop unrolling increases Compact circuit gas costs and proving time because it expands the circuit into static gates, multiplying the gate count and heavily inflating the proof generation workload during execution.

Monitor data points including gate counts from unrolled loops, frequency of ledger writes, and hash usage patterns to identify hot paths, then apply heuristics like structuring maps efficiently to reduce gas and proving time.

You can forecast Compact circuit costs by analyzing the circuit design to estimate proving costs, runtime gas, and state costs, identifying hot paths that blow up proofs, and applying mitigations to bound state growth.