Using the APIs
This section is part of a series on the topic of Development.
Connecting to the APIs
As most of the APIs are designed to be used for trading-related queries, the best place to try them out is on the testnet network, also known as Fairground. The public endpoints differ between testnet and mainnet, as do the network configurations your Vega-compatible wallet needs in order to connect. See the public endpoints page for details.
To use the Vega APIs, a developer will need access to a network-compatible instance of the relevant software, depending on their goals: core node, data node, and/or Vega Wallet.
Mainnet: Consensus validators may provide public endpoints for accessing the mainnet APIs, however that does not mean they should be relied upon for constant uptime and full access to all APIs. Each Vega Wallet release for mainnet wallet is pre-configured with any publicly announced nodes at the time of release.
Validator testnet: Some consensus validators may provide public endpoints for accessing the APIs on the validator testnet network, however that does not mean they should be relied on for constant uptime or full access to APIs.
Fairground: The project team operate a number of data nodes with publicly available endpoints for the Vega-run testnet, called Fairground. Each Fairground wallet app release is pre-configured with known nodes, including those operated by the project team, at the time of release.
Some rate limiting is implemented with default limitations on the APIs. For specific details, see the REST overview and WebSocket streams pages.
Formatting and field conventions
Strings vs numbers format
When using an API, in many cases the field is described as requiring a number but the data type is a string. Numerical fields are passed in string format so that there is no loss of precision, or risk of integer overflow for large numbers.
The APIs don't provide or accept decimal points in numbers or strings, so the decimal precision must be calculated and the number represented in integers, depending on what decimal precision the number needs.
- For quotes and prices, use the market decimal places to calculate, which can be found by querying for a market's parameters and using
- For fees, margin, and liquidity, use the settlement asset decimal places to calculate, which can be found by querying an asset's parameters and using
Unless otherwise specified, response timestamps, are encoded as a Unix timestamp, which is counted from midnight on 1 January, 1970. Requests that require timestamps will also need to be submitted in Unix time. Whether it's a nanosecond, second, or other, is signposted in the tutorial or API reference documentation.
REST for easy API access
REST provides endpoints for querying for trading data, account information, ledger movements, asset and market information, and much more. While the data provided through REST can come from three different places, the bulk of data can be acquired by querying the trading data API, which is served through data nodes.
REST is easy to get started with, and Vega supports nearly all the functionality provided by gRPC and GraphQL though REST.
Using REST: Read the REST overview for everything you need to know before using the endpoints, like the default rate limits and how to paginate results.
WebSockets for streaming
WebSocket endpoints offer real-time updates to changes in the state of the Vega network, allowing subscriptions to events such as per-market trades or changes to a party's position.
gRPC for fast interactions
gRPC provides fast and efficient communication, and supports near real time streaming of updates from Vega.
GraphQL for web apps
GraphQL is an alternative to REST that can be used to craft more complex queries.
Try out queries and learn the structure with the GraphQL playground ↗
Vega Wallet integration
To integrate the Vega Wallet with a dApp or bots, you'll likely need to use the wallet API.
The Wallet API uses JSON-RPC with an HTTP wrapper. Find out how to use the API before jumping into the reference docs.
Download a Vega Wallet to use the Wallet API to programmatically interact with the network for your own transactions.
Vega uses ERC-20 assets from Ethereum, and to facilitate inter-chain interactions between Vega and Ethereum, those assets are then transferred through a series of smart contract bridges. These bridges provide a seamless experience for users, allowing them to use Ethereum assets on the (non-Ethereum) Vega chain.
Moreover, these smart contract bridges operate just like any other smart contract on Ethereum, meaning that users can interact with them directly using an Ethereum JSON-RPC node or a service like Etherscan ↗, which provides a user-friendly interface for exploring and interacting with Ethereum smart contracts.
Smart contracts overview: Explore the contracts.
- ERC20 Bridge Logic
- Contains the functions necessary to deposit, withdraw, list assets, etc. It's controlled by Multisig Control and controls Asset Pool.
- ERC20 Asset Pool
- Holds deposited assets and remits them to provided addresses based on orders from the assigned Bridge Logic. It is controlled by Bridge Logic and Multisig Control.
- Multisig Control
- Handles verification of orders signed by a threshold of validators.
- Staking Bridge
- Allows users to deposit and withdraw VEGA tokens for staking. The VEGA tokens are always controlled exclusively by the tokenholder, even when on the Staking Bridge. Stake can be removed at any time by the tokenholder.
- VEGA Token contract
- ERC20 token smart contract.
- Vesting contract
- All VEGA tokens are issued through this. Handles the linear vesting of VEGA tokens and allows users to stake VEGA they own (vested or not).