README.md

# substrate-contracts-node

This repository contains Substrate's [`node-template`](https://github.com/paritytech/substrate/tree/master/bin/node-template)
configured to include Substrate's [`pallet-contracts`](https://github.com/paritytech/substrate/tree/master/frame/contracts)
‒ a smart contract module.

This repository is tracking Substrate's `master`.

_It contains a couple of modifications that make it unsuitable for a
production deployment, but a great fit for development and testing:_

* The unstable features of the [`pallet-contracts`](https://github.com/paritytech/substrate/tree/master/frame/contracts)
  are enabled by default (see the [`runtime/Cargo.toml`](https://github.com/paritytech/substrate-contracts-node/blob/main/runtime/Cargo.toml)).
* The consensus algorithm has been switched to `manual-seal` in
  [#42](https://github.com/paritytech/substrate-contracts-node/pull/42).
  Hereby blocks are authored immediately at every transaction, so there
  is none of the typical six seconds block time associated with `grandpa` or `aura`.
* _If no CLI arguments are passed the node is started in development mode
  by default._
* _With each start of the node process the chain starts from genesis ‒ so no
  chain state is retained, all contracts will be lost! If you want to retain
  chain state you have to supply a `--base-path`._
* For `pallet_contracts::Config` we increased the allowed contract sizes. This
  avoids running into `CodeTooLarge` when uploading contracts during development.
  See the comment in [`runtime/src/lib.rs`](https://github.com/paritytech/substrate-contracts-node/blob/main/runtime/src/lib.rs)
  for more details.

If you are looking for a node suitable for production see these configurations:

* [Substrate Node Template](https://github.com/paritytech/substrate/tree/master/bin/node-template)
* [Substrate Cumulus Parachain Template](https://github.com/paritytech/cumulus/tree/master/parachain-template)
* [Contracts Parachain Configuration for Rococo](https://github.com/paritytech/cumulus/tree/master/parachains/runtimes/contracts/contracts-rococo)

## Installation

### Download Binary

The easiest way is to download a binary release from [our releases page](https://github.com/paritytech/substrate-contracts-node/releases)
and just execute `./substrate-contracts-node --dev`.

### Build Locally

Follow the [official installation steps](https://docs.substrate.io/v3/getting-started/installation/)
to set up all Substrate prerequisites.

Afterwards you can install this node via

```bash
cargo install contracts-node --git https://github.com/paritytech/substrate-contracts-node.git --force --locked
```

The `--locked` flag makes the installation use the same versions
as the `Cargo.lock` in those repositories ‒ ensuring that the last
known-to-work version of the dependencies are used.

The latest confirmed working Substrate commit which will then be used is
[b0777b4](https://github.com/paritytech/substrate/tree/b0777b4c7f7d8d3c635319d0153953d0a22aa58e).

## Usage

To run a local dev node execute

```bash
substrate-contracts-node --dev
```

A new chain in temporary directory will be created each time the command is executed. This is the
default for `--dev` chain specs. If you want to persist chain state across runs you need to
specify a directory with `--base-path`.

### Show only Errors and Contract Debug Output

To have only errors and contract debug output show up on the console you can
supply `-lerror,runtime::contracts=debug` when starting the node.

Important: Debug output is only printed for RPC calls or off-chain tests ‒ not for transactions!

See our FAQ for more details:
[How do I print something to the console from the runtime?](https://paritytech.github.io/ink-docs/faq/#how-do-i-print-something-to-the-console-from-the-runtime).

## Connect with frontend

Once the node template is running locally, you can connect to it with frontends like [Contracts UI](https://contracts-ui.substrate.io/#/?rpc=ws://127.0.0.1:9944) or [Polkadot-JS Apps](https://polkadot.js.org/apps/#/explorer?rpc=ws://localhost:9944) and interact with your chain.