Learning-Bitcoin-from-the-Command-Line/A3_2_Mining_with_Regtest.md

# A3.2: Mining the Regtest

> **NOTE:** This is a draft in progress, so that I can get some feedback from early reviewers. It is not yet ready for learning.

This document explains how to generate (i.e. mine) blocks using a Regtest (Regression Test) blockchain.
To generate blocks on a new blockchain requires very minimal proof-of-work and it will take less than a second, due to the low difficulty and because it follows the Testnet rules.

## Generating blocks

You can generate (mine) new blocks on a regtest chain using the RPC method `generate` with an argument of how many blocks to generate. It only makes sense to use this method on regtest; due to the high difficulty it's very unlikely that it will yield to new blocks in the mainnet or testnet:
```
$ bitcoin-cli -regtest generate 101
[
  "57f17afccf28b9296048b6370312678b6d8e48dc3a7b4ef7681d18ed3d91c122",
  "631ff7b8135ce633c774828be3b8505726459eb65c339aab981b10363befe5a7",
  ...
  "1162dbfe025c7da94ee1128dc26d518a94508f532c19edc0de6bc673a909d02c",
  "20cb2e815c3d42d6a117a204a0b5e726ab641c826e441b5b3417aca33f2aba48"
]
```
Because a block must have 100 confirmations before that reward can be spent, we generate 101 blocks, providing access to the coinbase transaction from block #1. Because this is a new block chain using Bitcoin’s default rules, the first blocks pays a block reward of 50 bitcoins. Unlike mainnet, in regtest mode only the first 150 blocks pay a reward of 50 bitcoins. The reward halves after 150 blocks, so it pays 25, 12.5, and so on...

The output is the block hash of every block generated.

## What's Next?

After starting your bitcoind on regtest and generating the first blocks, you have balance in your address to spend and [test using Regtest blockchain](A3_3_Testing_with_Regtest.md).