# Agoric REPL

Note: This page describes the Agoric REPL. For information about the Node.js REPL, click here (opens new window).

# Introduction

When you run agoric start --reset, you start a local ag-solo.

You use agoric start to start what we call an ag-solo, which is a single personal local Agoric node. You need an ag-solo running on your machine to interact with Agoric network services, whether a built-in simulated chain (also started by agoric start), or a fully-decentralized public Agoric blockchain.

All deployment happens via the local running Agoric process. This is usually the ag-solo process, and frequently referred to as that or just as ag-solo. It is also sometimes described as/called an Agoric VM or a local server.

An ag-solo communicates with either a locally running or remote chain. This local process (the ag-solo) has a home object, which contains references to services on-chain, including Zoe, the Board for sharing objects, and an application user's Wallet, among others. Developers can use these service references to call the service's associated API commands.

Contract code starts in a file on a user's computer, either written by them or imported from agoric/zoe. The code is bundled; turned into a particularly formatted blob of code that exists in memory while a deploy script is running. When E(zoe).install() is called, the blob is sent to and stored on-chain so that Zoe can access it.

An ag-solo has an associated REPL (Read-Eval-Print Loop). From the REPL and the home object, developers can use all the on-chain commands that deployment scripts use to deploy contracts and Dapps. In addition to the on-chain commands, they can also run any other JavaScript commands from the REPL.

# Accessing the REPL

Once an ag-solo is running and on-chain, you can access its associated REPL in two ways.

  • In a browser tab, go to localhost:8000. Depending on the browser's width, you will see the Wallet UI and REPL either in separate columns or separate rows.

Wallet and REPL

Wallet and REPL

  • From a shell, run agoric open --repl This opens the user's Wallet UI and its associated REPL. To open only the REPL, run agoric open --repl only

REPL

# Using the REPL

You can run JavaScript commands from the REPL. You can also use the REPL's home object's predefined connections to other objects and services. To see what’s available, just type home into the REPL:

home

Command[1] home
History[1] {"chainTimerService":[Presence o-50],"sharingService":[Presence o-51],"contractHost":[Presence o-52],"ibcport":[Presence o-53],"registrar":[Presence o-54],"registry":[Presence o-55],"zoe":[Presence o-56],"localTimerService":[Presence o-57],"uploads":[Presence o-58],"spawner":[Presence o-59],"wallet":[Presence o-60],"network":[Presence o-61],"http":[Presence o-62]}

The results of what is entered into the REPL is saved under history[N]

The following sections describe the home objects developers can use. Click on the section header to go to more detailed documentation about that object. Several home objects are either for internal Agoric use only or have been deprecated. These are listed together in the final section. External developers should ignore them and not try to use them.

# wallet

Holds on-chain digital assets and object capabilities on behalf of the user. The header link takes you to the standard non-REPL specific wallet API documentation. When calling wallet API methods from the REPL, wallet must be prefaced by home. and use E(). For example, E(home.wallet).getPurses()

# chainTimerService

On-chain time authority used to schedule events.

# localTimerService

Local off-chain time authority used to schedule events.

# board

Shared on-chain location where users can post generally accessible values.

# sharingService

Share on-chain objects with other users without making them available to the general public. In particular, you can share items between vats connected to the same remote chain.

# ibcport

IBC implementation that lets vats open and close listening ports, connect and disconnect to/from remote ports, and send and receive data over those connections.

# zoe

Deploy and interact with smart contracts. Zoe protects smart contract users by escrowing digital assets and guaranteeing users get either what they want or get a refund of what they escrowed. Even if the contract is buggy or malicious. The header link takes you to the standard, non-REPL specific, zoe API documentation. When calling any of the zoe API methods from the REPL, zoe must be prefaced by home. and use E(). For example, E(home.zoe).getFoo()

# priceAuthority

Get price quotes for pairs of digital assets.

# scratch

An off-chain, private, place to store key-value pairs on your ag-solo for later use.

# Deprecated and Internal-only Objects

  • contractHost: Replaced by the spawner object.
  • faucet: Internal for chain setup.
  • http: api/deploy.js uses this to install new HTTP and WebSocket handlers in an ag-solo. You should not need to use it.
  • network: Privileged object for internal use.
  • plugin: Privileged object for internal use.
  • priceAuthorityAdmin: Privileged object for internal use.
  • registrar: Deprecated.
  • registry: Deprecated.
  • spawner: Privileged object for internal use.
  • uploads: Deprecated name for scratch.
  • vattp: Privileged object for internal use.