# Install Dev Environment

## Install prerequisites

To install the dev environment in your local machine, you'll need some prerequisite software already installed:

* Git
* Docker: install docker and "docker compose". Note that we've only tested using the current version of Docker (20.10.23) and we suggest keeping your Docker updated to the latest version.
* Rust
* Node.js

Note that you'll need to use node version 14.14.0 for this tutorial. Make sure you have nvm 14.14.0 installed and set as default:

```
nvm install 14.14.0
nvm use 14.14.0
```

You can check which version of node is active using `nvm current`.

If you haven't installed wasm32-unknown-unknown target or the nightly version, you might be prompted to `rustup` and install them according to the instructions.

* `rustup target add wasm32-unknown-unknown`
* `rustup install nightly`

One of the build scripts that are used in the following tutorials might prompt that `protoc` couldn't be found. You can [follow the instructions to install it](https://grpc.io/docs/protoc-installation/#install-using-a-package-manager):

* **On a Mac**: `brew install protobuf`
* **On Ubuntu**: `apt install -y protobuf-compiler`

## Install local development environment: Dev-Runner

The purpose of the `dev-runner` repo is to allow any user to recreate the TEA runtime on their local machine. The TEA Project is a decentralized system that needs multiple nodes for both its hosting infrastructure and [state machine](/z_glossary/state_machine.md) where a [remote attestation](/z_glossary/remote_attestation.md) process ensures that all nodes are trustable. In the simplified local runtime, there's only one [hosting node](/z_glossary/hosting_cml.md) ("B-node") and one state machine node ("A-node"). And there's no remote attestation since this is a simulated environment with a single node on each level.

To install `dev-runner` to your local environment, use the following command:

`git clone https://github.com/tearust/dev-runner.git`

After you've dowloaded the `dev-runner` to your local computer, note that other repos will possibly interact with your local **dev-runner** environment as a sibling folder. For example, `tutorial-v1` will write a wasm file to `dev-runner` during the build process for that tutorial.

## Troubleshooting the Dev Environment

The most common cause of errors during the following tutorials generally either arise from an improperly configured local environment or from not having the most up to date repo.

* Misconfigured local environments can be fixed by following the error messages requesting missing packages. The prerequisites at the top of this document should be sufficient but everyone's local development environment will be unique.
* `git pull` your current tutorial's repo to make sure you have the latest files.

If you either change your local software environment or update your local repos, you'll need to stop any existing TEA runtime docker images. These are the steps for refreshing the `dev-runner` repo and associated docker images:

* Press `CTRL-C` to stop **dev-runner**.
* `docker compose down` (or `docker-compose down`) to stop the docker containers.
* Delete the `.tokenstate` using `rm -rf .tokenstate` to clear the stored state. This directory contains the local state's persistent storage in local dev mode. If you don't delete it, the next time you start the dev-runner will continue from the last saved [state](/z_glossary/state.md) . This may cause conflicts if you've updated your code logic.
* If there are any updates of the dev-runner docker images, use `docker pull the_images_of_the_two_:dev_image` to update the existing older images if there's an updated image available:

```
docker pull tearust/parent-instance-client:dev
docker pull tearust/runtime:dev
```

* After you've built the tutorials using your latest updates you'd run `docker-compose up` from the `dev-runner` directory.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://dev.teaproject.org/020_tutorial/010_install-dev-env.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.