# melnode: Mel's reference implementation
[![](https://img.shields.io/crates/v/melnode)](https://crates.io/crates/melode)
![](https://img.shields.io/crates/l/melnode)
[Mel](https://melproject.org) is a new public blockchain focused on security, performance, and long-term stability. `melnode` is Mel's reference implementation in Rust.
## Installation
For security reasons, until we have reliable reproducible build infrastructure, the only official distribution channel for `melnode` is its source code package on [crates.io](https://crates.io).
Fortunately, installing `melnode` from source is extremely easy. First, make sure [cargo](https://doc.rust-lang.org/cargo/getting-started/installation.html) is installed on your machine. Then, simply run
```
$ cargo install --locked melnode
```
This produces an executable `melnode` in `~/.cargo/bin/`, which should already be in your `$PATH`.
## Hardware Requirements
### Minimum:
- 1-core CPU
- 4GB of RAM
- at least 200GB of free storage (SSD not necessary)
- 10 Mbit/sec download Internet service
### Recommended:
- 4+ core CPU
- 16GB of RAM
- 200+GB of free storage on a fast device (SSD, RAID array, etc)
- 50+ Mbit/sec up/download Internet service
Full nodes replicate every consensus-confirmed block, validating its contents and ensuring network security while providing a local cache of the entire blockchain state. Running a full node helps contribute to the security and (read) performance of the network.
There are two kinds of full nodes:
- **Replica nodes** comprise the vast majority of full nodes. They replicate and verify blocks but do not vote in consensus.
- **Staker nodes**, the ultimate guardians of Mel security, have SYM locked up and participate in consensus. They are analogous to miners in proof-of-work blockchains like Bitcoin.
## Auditor Full Node
### On the Mel Mainnet:
To run an replica on the “mainnet” (which at the moment is far from stable, but does have a persistent history), just run:
```
$ melnode
```
`melnode` will then beginning synchronizing all the blocks in the blockchain. This will take quite a while (a day or so) and store a bunch of data in in `~/.melnode/`.
### On the Mel Testnet:
To run the replica on the non-persistent testnet, where most covenant development and testing will happen during the betanet period, run instead
```
$ melnode --bootstrap tm-1.themelio.org:11814 --testnet
```
Note that two things were needed to connect to the testnet:
- Connecting to a testnet bootstrap node (this is the first server your full node talks to)
- Specifying --testnet, to use testnet validation rules
### Configurations
You can change the configuration of an replica node with the following flags:
```
--bootstrap <bootstrap>...
Bootstrap addresses. May be given as a DNS name [default: mainnet-bootstrap.themelio.org:11814]
--database <database> Database path [default: /tmp/themelio-mainnet]
--listen <listen> Listen address
--testnet Use testnet validation rules
--override-genesis <override-genesis>
If given, uses this YAML file to configure the network genesis rather than following the known
testnet/mainnet genesis
```
### Local simnet support
**Note**: there will soon be a tool to automatically generate these configurations.
We can configure a simnet --- a "fake" network local to our computer --- by the combination of three options:
- `--bootstrap 127.0.0.1:11814` to bootstrap only with ourselves instead of any remote node
- `--override-genesis network-config.yaml`, where `custom-config.yaml` contains configuration for a _custom network_ of the following form:
```yaml
network: custom02 # anything from custom02..custom08
# specifies the "initial stash" of money in the genesis block
init_coindata:
# what address gets the initial supply of money
covhash: t5xw3qvzvfezkb748d3zt929zkbt7szgt6jr3zfxxnewj1rtajpjx0
# how many units (in millionths)
value: 1000000
# denomination
denom: MEL
# additional data in the UTXO, as a hex string
additional_data: ""
# specifies all the stakers with consensus power.
# we need to specify ourselves in order to produce any blocks; "themelio-crypttool generate-ed25519" (install via cargo) can generate a keypair for us
stakes:
deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef:
pubkey: 4ce983d241f1d40b0e5b65e0bd1a6877a35acaec5182f110810f1276103c829e
e_start: 0
e_post_end: 100000 # essentially never end the stake
syms_staked: 10000 # does not matter
# Initial fee pool
init_fee_pool: 10000
# Initial fee multiplier
init_fee_multplier: 1
```
- `--staker-cfg staker-config.yaml` must contain a _staker_ configuration like this:
```yaml
# secret key; must correspond to "stakes.dead[...]beef.pubkey" in the network config
signing_secret: 5b4c8873cbdb089439d025e9fa817b1df1128231699131c245c0027be880d4d44ce983d241f1d40b0e5b65e0bd1a6877a35acaec5182f110810f1276103c829e
# address for staker-network communication, this can be arbitrary
listen: 127.0.0.1:20000
# must be same as "listen"
bootstrap: 127.0.0.1:20000
# where block rewards are sent
payout_addr: t5xw3qvzvfezkb748d3zt929zkbt7szgt6jr3zfxxnewj1rtajpjx0
# vote for this fee multiplier (higher values charge more fees)
target_fee_multiplier: 10000
```
A more detailed explanation of `--staker-cfg` requires explaining the staker and consensus system, as follows:
## Staker Full Node
### On the Mel Mainnet:
WIP
### On the Mel Testnet:
WIP
### Configuration
WIP
## Contributing
Thank you for considering contributing to the Mel source code! We welcome all contributions from absolutely anyone on the internet.
For minor changes, simply fork, fix, and submit a pull request. If you want to propose a larger change, be sure to get in touch with our dev team on [Discord]() to make sure your change aligns with Mel's overarching philosophy. This will likely save you a significant amount of time and effort, as well as speed up the review process of your change.
Finally, make sure your code adheres to the following guidelines:
- Your code must adhere to the official Rust [style guide](https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/guide.md)
- Your code must be documented per the official Rust [documentation guidelines](https://rust-lang.github.io/api-guidelines/documentation.html)
- Pull requests must be based on and opened against the `master` branch
- Commit messages must be descriptive
- Any protocol changes (whether consensus-breaking or not) must start as a TIP (e.g. [TIP-101](https://github.com/themeliolabs/melnode/issues/87))
## License
The license of the project is the Mozilla Public License, version 2.
---