> For the complete documentation index, see [llms.txt](https://dev.teaproject.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.teaproject.org/020_tutorial/020_hello_world/022_dev-runner_the_local_development-environment.md). # Step 2: Start the Local Dev Environment ## Unit test ->Dev runner ->Test net -> Production TApp development needs 4 basic steps. * Unit test: Run `cargo test` after every code change. This is the fastest way to test the logic. * Dev runner: The local development environment. It's a simulator of the TEA Project runtime but running locally. Like Hardhat for Ethereum, this is the quickest way to test and verify the front end and back end logic integration. * Testnet: This is **almost** the same as the final production environment but all the assets are not real so any mistakes won't cause real fund losses. * Production: This is the last step where code is run in the real production environment. Please note that any mistake in your code may cause **real** fund losses. In the previous step, we walked through the unit test. In this step, we'll walk through the Local Development Environment, called "Dev Runner". The local development environment (dev-runner) is a docker configuration. It simulates one hosting node and one state machine node that runs in your local computer under docker. There's no hardware protection, so all Remote Attestation and consensus are simulated. ## Prerequisites for Installation * Git * Docker: install docker (version 20.10.23 or above) and "docker compose" * Node.js. Again, make sure you're using node version 14.14.0. ## Running the tests ### Prepare your custom actors If you have any custom wasm [actors](https://github.com/tearust/t-rust/blob/master/docs/_gitbook-dev-docs/020_tutorial/020_hello_world/z_glossary/actor.md) that need to be loaded, you should place them in the directory `local`. In our sample-actor case, you can find the file located in the `tutorial-v1` repo at `~/sample-actor/target/wasm32-unknown-unknown/release/sample_actor.wasm`. Note that this file will be copied to the `local/b-node` folder of the `dev-runner` repo as part of the build process, and the **dev-runner** will load all wasm actors inside the `local` folder. Let's build the **sample\_actor.wasm** file and copy it into the `dev-runner` repo. From the `tutorial-v1` repo, run `./build.sh` in the `sample-actor` folder to build the wasm file. In the last step of the build file it will copy it to the `local/b-node` directory of `dev-runner`. ### Start the docker container servers You can run with server mode by doing the following: ``` docker compose up ``` (If you installed `docker-compose` please replace the `docker compose up` command with `docker-compose up`) Please wait for all the containers to start and confirm that the log isn't showing any errors. ### Use CURL to send json http post request without front end While the server's running, open another terminal and run the following: ``` curl -H "Content-Type: application/json" -d '{"actor": "someone.sample", "address": "0x0000000000000000000000000000000000000000"}' http://localhost:8000/say-hello ``` You should see the following output: ``` "Hello world!" ``` Now you know the server is running and the sample actor responds as expected. You can also use Postman or any testing tools to simulate a front end sending requests to the server. Just make sure: * Use the following address: `localhost:8000/say-hello` * json request * http post * Use the json request as given above In our next session we'll create a sample-front-end project. It will run such requests in the browser to make future tutorials easier. ### Start the front end Make sure you're in the `sample-front-end` folder of the `tutorial-v1` repo and to start the front-end run the following commands: ``` npm install npm start ``` Open a browser and visit \[[http://127.0.0.1:3200](http://127.0.0.1:3200/)]. You should see a page with the text "Welcome to Sample Actor testing page" and a single button, "click here to send request". ![Screenshot 2023-04-28 at 2 27 33 PM](https://user-images.githubusercontent.com/86096370/235257641-28880e62-5542-4582-99da-a3705bec0647.png) Clicking on the button should result in a "Hello world!" popup. Please make sure your dev-runner is up and running. If not, follow the instructions in the previous steps. If the backend is running correctly, you can click the button to send a request to the sample-actor. You should see the response in a browser alert: ``` {"data":"Hello world!","status":200,"statusText":"OK","headers":{"content-length":"14","content-type":"application/json"},"config":{"url":"/say-hello","method":"post","data":"{\"actor\":\"someone.sample\",\"address\":\"0x000000000000000000000000000000000000000f\"}","headers":{"Accept":"application/json, text/plain, */*","Content-Type":"application/json;charset=utf-8"},"baseURL":"http://127.0.0.1:8000","transformRequest":[null],"transformResponse":[null],"timeout":0,"xsrfCookieName":"XSRF-TOKEN","xsrfHeaderName":"X-XSRF-TOKEN","maxContentLength":-1,"maxBodyLength":-1},"request":{}} ``` Congratulations! Your first TApp is correctly running in your local development environment. In the next step, you'll learn how to deploy it to the testnet. ## Limitations of dev-runner Dev-runner is a docker simulation of the real TEA-runtime. It's different in the following aspects: * There's no hardware security. * There's only one host node and one state machine node. * No consensus is required since there's only one state machine node. * There's no real remote attestation. All nodes are assumed to be "good " nodes. * There's no layer-1 (Ethereum) interaction. * All initial funding is provided in the DAO\_RESERVE account. Of course, this money is fake. You can stop the docker container at any time, and it will get back to the original state when you restart . You cannot store the state. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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/020_hello_world/022_dev-runner_the_local_development-environment.md?ask= ``` 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.