5.2 Usage

Reach has a few sub-commands, each with their own options.

However, all commands support the following options:

• The environment variable REACH_VERSION signifies what version of Reach to use.

5.2.1 reach compile

You compile your Reach code by executing

  $ reach compile SOURCE EXPORT ...

where SOURCE is your source file, and each EXPORT is an exported Reach.App.

If no SOURCE is provided, then index.rsh is used.

If no EXPORT is provided, then all the exported Reach.Apps will be compiled. If there are no Reach.Apps exported, then the program will be compiled as a library, where its exports are available to other Reach programs and frontends. The output name of a library is the same as if it exported a Reach.App named default.

reach compile supports the following options:

• -o/--output ‹OUTPUT› — Writes compiler output files to ‹OUTPUT›, which defaults to a directory named build in the same directory as SOURCE.

• --intermediate-files — Write intermediate files, which may be interesting for debugging compilation failures or using in other contexts.

• --install-pkgs — Allows Reach to fetch remote package imports and stop after doing so.

  Reach will fail with an error message if package imports have not yet been fetched and this flag is not activated.

  Using this flag will create a .reach directory for your project. This directory stores your project’s lockfile, which is how Reach pins remote packages to specific versions. It is recommended that you commit the .reach directory to source control. Deleting this directory is also safe; it can easily be rebuilt by using the --install-pkgs flag again; in fact, this is the best way to upgrade your packages.

• --stop-after-eval — Stops the compilation process before verification and producing output files. This might be useful for performing syntax and type checking quickly.

• --verify-timeout ‹TIMEOUT-MS› — Sets the timeout of individual verification theorems, in milliseconds. The default value is 2 minutes.

• The environment variable REACH_DEBUG, if set to any non-empty value, enables debug messages from the Reach compiler, which will appear in the console. This debug information includes: the estimated cost of the contract on Algorand.

5.2.2 reach init

You can create template index.rsh and index.mjs files for a simple Reach app by running

  $ reach init

5.2.3 reach run

You can run a simple Reach application by executing

  $ reach run [APP or DIR] [ARGS]

APP represents a Reach module name without its extension (e.g. "index" by default).

If no APP or DIR is provided then index in the current working directory is assumed.

If DIR matches an existing, relative subdirectory of the current working directory then DIR/index is used.

ARGS represents zero or more arguments to be passed into APP’s frontend.

This assumes

• Your Reach program is named APP.rsh.

• You are using the JavaScript backend and your frontend is named APP.mjs. It also assumes the backend is located at DIR/build/APP.main.mjs, and only depends on the Reach standard library.

It then

• Compiles your program with Reach.

• Builds a Docker image named reachsh/reach-app-APP:latest that depends on the Reach JavaScript standard library.

• Executes a container based upon that image while connected to the network determined by REACH_CONNECTOR_MODE.

reach run supports the following options:

• The environment variable REACH_CONNECTOR_MODE specifies which context to run in. The default, if this variable is unset or empty, is ETH-devnet. The options are:

  • ETH-live, which uses a live Ethereum network node, specified by the environment variable ETH_NODE_URI.

  • ETH-browser, which uses Ethereum via a browser extension, like MetaMask.

  • ETH-devnet, which uses a Dockerized private Ethereum network.

  • ALGO-live, which uses a live Algorand network node, specified by the environment variables documented in the Algorand connector section.

  • ALGO-browser, which uses Algorand via an ARC-0011 browser wallet.

  • ALGO-devnet, which uses a Dockerized private Algorand network.

• The environment variable REACH_DEBUG, if set to any non-empty value, enables debug messages from the Reach standard library, which will appear in the console.

reach run can be further specialized via the presence of a Dockerfile and package.json file. If either are absent, reach run assumes a default behavior (which may be persisted with reach scaffold).

The Dockerfile can be modified to introduce new dependencies, services, or filesystem prerequisites into your app’s containerized environment, and the package.json file may likewise be extended to include additional libraries or make configuration changes to the resultant Node.js package.

5.2.4 reach down

You can halt all Dockerized Reach apps and devnets by running

  $ reach down

5.2.5 reach scaffold

You can create templated Dockerfile and package.json files for a simple Reach app by running

  $ reach scaffold

The files created are the same as those used temporarily by reach run.

5.2.6 reach react

You can run a simple React app by executing

  $ reach react

This assumes

• Your Reach program is named index.rsh

• Your frontend React program is named index.js

It then

• Compiles your program with Reach

• Runs the appropriate devnet based on REACH_CONNECTOR_MODE

• Mounts the current directory into /app/src/ in the reachsh/react-runner Docker image and runs it.

reach react supports the following options:

• The environment variable REACH_CONNECTOR_MODE specifies which context to run in. The default, if this variable is unset or empty, is ETH. The options are:

  • ETH, which runs a Dockerized private Ethereum network which may be used. The app can use any Ethereum network.

  • ALGO, which runs a Dockerized private Algorand network which may be used. (Support for using any Algorand network is forthcoming with TEAL 3.)

• The environment variable REACH_DEBUG, if set to any non-empty value, enables debug messages from the Reach standard library, which will appear in the browser console.

When using loadStdlib in conjunction with reach react, be sure to pass in process.env as its argument. See loadStdlib for details.

reach react does not respect the same scaffolded files as reach run. It is just a simplified tool to give you a taste of web programming with reach. If you would like access to more customizations on a browser-based project, such as custom environment variables, custom JavaScript dependencies, or using other JavaScript frameworks like Angular, we recommend that you simply use reach compile, and use your own preferred JavaScript setup for the project. The compiled build/index.main.mjs JavaScript file and the '@reach-sh/stdlib' JavaScript library may be used in any JavaScript project like any other JavaScript file and library, respectively.

5.2.7 reach devnet

You can run a private Reach devnet by executing

  $ reach devnet

reach devnet supports the following options:

• --await-background — Run in background and await availability.

• The environment variable REACH_CONNECTOR_MODE specifies which devnet to run. The default, if this variable is unset or empty, is ETH. The options are:

  • ETH, which runs an Ethereum devnet on localhost:8545

  • ALGO, which runs an Algorand devnet on localhost:4180 and an Algorand indexer on localhost:8980

• The environment variable REACH_DEBUG enables some additional debugging information for the Algorand devnet, which is accessible via http://localhost:9392

5.2.8 reach rpc-server

The sub-command

  $ reach rpc-server

starts an instance of the Reach RPC Server using all of the same options and defaults as reach run.

reach rpc-server supports the following options:

• The environment variable REACH_RPC_KEY is used to determine the RPC server key. If not defined, it defaults to opensesame, and a warning will appear in the console stating that the development key is being used.

  In a production context this key must be kept secret, and it should be randomly generated with a suitably strong method, such as:

    $ head -c 24 /dev/urandom | base64

• The environment variable REACH_RPC_PORT is used to determine which port to bind to. It defaults to 3000.

• The environment variable REACH_RPC_TLS_KEY is used to determine the path to the TLS key file, which must be in the ./tls directory. It defaults to reach-server.key.

• The environment variable REACH_RPC_TLS_CRT is used to determine the path to the TLS crt file, which must be in the ./tls directory. It defaults to reach-server.crt.

• The environment variable REACH_RPC_TLS_PASSPHRASE is used to determine the TLS passphrase. It defaults to rpc-demo.

5.2.9 reach rpc-run

The sub-command

  $ reach rpc-run CMD

is a convenient means of launching a pre-configured RPC server and frontend which are suitable for development purposes. It uses a REACH_RPC_KEY value of opensesame (the standard development API key), and sets REACH_RPC_TLS_REJECT_UNVERIFIED to 0.

5.2.10 reach docker-reset

You can easily kill and remove all Docker containers by executing

  $ reach docker-reset

This can be a useful thing to try if your Docker containers stop responding to requests or otherwise misbehave, or if you have updated your Reach images (with reach update) but those changes are not taking effect. This command is a loose approximation of "turning Docker off and on again." It will affect all Docker containers on your machine, not just those created by Reach.

5.2.11 reach upgrade

You can upgrade your Reach installation by executing

  $ reach upgrade

This may change the default version used by reach commands.

5.2.12 reach update

You can update the Docker images used by your Reach installation by executing

  $ reach update

This may change the patch version used by reach commands.

5.2.13 reach version

You can see what version of Reach you have installed by running

  $ reach version

5.2.14 reach hashes

You can see which exact versions of Reach Docker images you are using by running

  $ reach hashes

This is more precise, but less readable, than reach version, in that each hash refers to the git commit used to build the image.