Nanvil documentation
Nanvil is a Neo3 local development node inspired by Foundry Anvil. Use it for instant chains, prefunded accounts, mainnet/testnet forking, dev RPC cheats, and a built-in block explorer.
Quick links
| Topic | Description |
|---|---|
| Getting started | Install from release, start a node, first transaction |
| Examples cookbook | End-to-end workflows with copy-paste commands |
| CLI reference | nanvil, ncast, and nsmith flags and commands |
| nsmith compiler | Multi-language contract compilation (Go, Python, Java, C#) |
| RPC reference | nanvil_* JSON-RPC methods |
| Block explorer | Web UI, live updates, docs browser |
| Forking | Mainnet / testnet fork workflow |
| Impersonation | Dev witness bypass |
| State management | Snapshots, persistence, reset |
| Tracing | Invocation logs and debugging |
| Architecture | Components and data flow |
| Anvil comparison | vs Foundry Anvil |
| Fork troubleshooting | Common fork issues |
| Development | Build, test, contribute |
| Upstream sync | neo-go fork maintenance |
Default services
When you run ./bin/nanvil start:
| Service | URL |
|---|---|
| JSON-RPC | http://127.0.0.1:8545 |
| Block explorer | http://127.0.0.1:8546 |
| Documentation | http://127.0.0.1:8546/docs/ |
Default dev accounts
Mnemonic (10 accounts, 10,000 GAS each):
test test test test test test test test test test test junk
Query accounts at any time:
curl -s http://127.0.0.1:8545 -H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"nanvil_nodeInfo","params":[]}'
Or open the explorer and check the terminal output from nanvil start.