# subxt ·  [](https://crates.io/crates/substrate-subxt) [](https://docs.rs/substrate-subxt)
A library to **sub**mit e**xt**rinsics to a [substrate](https://github.com/paritytech/substrate) node via RPC.
## Usage
See [examples](./examples).
## Integration Testing
Most tests require a running substrate node to communicate with. This is done by spawning an instance of the
substrate node per test. It requires an executable binary `substrate` at [`v3.0.0`](https://github.com/paritytech/substrate/releases/tag/v3.0.0) on your path.
This can be done by downloading the prebuilt binary:
```bash
curl "https://releases.parity.io/substrate/x86_64-debian:stretch/v3.0.0/substrate/substrate" --output substrate --location
chmod +x ./substrate
mv substrate ~/.local/bin
```
Or installed from source via cargo:
```bash
cargo install --git https://github.com/paritytech/substrate node-cli --tag=v3.0.0 --force
```
**Alternatives**
[substrate-api-client](https://github.com/scs/substrate-api-client) provides similar functionality.
## Subxt Client
By default the client builder will connect to a full node via rpc. The `subxt-client` helps
embedding a light client directly. It can also be used to embed a full node. This is especially
useful for testing and ci.
#### License
<sup>
The entire code within this repository is licensed under the <a href="LICENSE">GPLv3</a>.
Please <a href="https://www.parity.io/contact/">contact us</a> if you have questions about the licensing of our
products.
</sup>