State management

Snapshots

{"method":"nanvil_snapshot","params":[]}
{"method":"nanvil_revert","params":["0x1"]}

Snapshots record block height. Revert calls Blockchain.Reset (requires chain not running — best used between test cases or after shutdown).

Dump / load

Full chain state (storage, fork overlay, fork manifest, snapshot list) is written on shutdown when --dump-state or --data-dir is set.

# Persist across stop/start with a data directory (recommended)
nanvil start --data-dir ./nanvil-data --fork-url http://seed1.neo.org:10332

# Or explicit dump/load paths
nanvil start --fork-url http://seed1.neo.org:10332 --dump-state ./chain.state.json
nanvil start --load-state ./chain.state.json

# Periodic dumps while running
nanvil start --data-dir ./nanvil-data --state-interval 60s

On restart with --load-state or --data-dir, nanvil restores the backing store and fork overlay, reconnects to the remote fork RPC, and skips bootstrap when the chain height is already past the fork branch.

Legacy metadata-only state files (height + snapshots without format: nanvil-chain-v1) are still supported for snapshot revert metadata.

Reset

nanvil_reset drops local blocks to genesis or fork branch point (requires node restart in current implementation).