Regtest is a private Bitcoin network you control. Difficulty is trivial, so you can mine blocks instantly and test multi-step flows without testnet faucets.
Why this matters
Mainnet is the wrong place to learn. Testnet is shared and flaky. Regtest is your lab bench.
Analogy
Regtest is a flight simulator. Crashes are free. You can rewind scenarios and practice emergencies before flying real capital.
Minimal loop
bitcoin-cli -regtest createwallet "alice"
ADDR=$(bitcoin-cli -regtest getnewaddress)
bitcoin-cli -regtest generatetoaddress 101 "$ADDR" # mature coinbase
bitcoin-cli -regtest sendtoaddress <bob> 10
bitcoin-cli -regtest generatetoaddress 1 "$ADDR"Loading diagram…
Docker tip
Compose bitcoind with fixed RPC ports and credentials for app containers. Mount a disposable volume.
Common mistakes
- Not mining 100+ blocks before spending coinbase
- Parallel tests sharing one node without isolation
- Hard-coding txids from a previous run
Worked mental model
Re-read the diagrams in this lesson once out loud in plain language. If you cannot explain the flow to a friend without jargon, pause and revisit Mastering Bitcoin / Mastering Lightning chapters linked in Resources. Chapter references are intentional, not decorative.
Hands-on habit
Every protocol idea should be paired with one local experiment:
- Reproduce the happy path on regtest (or Polar for Lightning)
- Break it on purpose (wrong fee, expired invoice, offline peer)
- Write down what error you saw and which layer produced it (wallet, node, mempool, peer)
That habit turns reading into builder instinct.
Glossary check
Pick three terms from this lesson and define them in one sentence each without opening notes. Weak definitions mean the lesson is not finished yet.
Resource order
Use Resources in order: narrative book chapter first, then BIP/BOLT for precision, then implementation docs for commands. Jumping straight to RPC flags without the mental model creates brittle knowledge.
Next steps
Learn PSBT workflows: how multi-device and multisig signing is coordinated safely.