Hermes

Hermes is a web service that listens to the Pythnet and the Wormhole Network for Pyth price updates, and serves them via a convenient web API. It provides Pyth's latest price update data format that are more cost-effective to verify and use on-chain.

Hermes allows users to easily query for recent price updates via a REST API, or subscribe to a server-side events stream for streaming updates. The Pyth Network's Javascript SDKs connect to an instance of Hermes to fetch price updates.

Documentation

The Hermes API Documentation provides a comprehensive explanation of Hermes API for user interaction. You can use the price service client library in JS to interact with Hermes.

Here's an example of retrieving the latest update of the ETH/USD price feed using curl.

# Example API call
$ curl https://hermes.pyth.network/api/latest_price_feeds?ids[]=0xff61491a931112ddf1bd8147cd1b641375f79f5825126d665480874634fd0ace

# Example Response
[{"id":"ff61491a931112ddf1bd8147cd1b641375f79f5825126d665480874634fd0ace","price":{"price":"184136023127","conf":"177166324","expo":-8,"publish_time":1692110601},"ema_price":{"price":"184100641000","conf":"178704085","expo":-8,"publish_time":1692110601}}]

Accessing Hermes

Hermes can be accessed through a third-party provider (similar to a blockchain RPC). The Pyth Data Association also operates a public instance for development purposes. Please see Hermes API Instances and Providers for more details.