GetBlock provides a fast and easy API connection to an xDai node. Different packages are available based on number of requests per day, including a free tier offering up to 40K requests/day.
To get started, simply sign up for an account and you will receive an API key. You can also request an unlimited number of API keys per account. Additional details on account setup are available here.
In addition to very high uptimes and a user-friendly dashboard, GetBlock docs feature handy resources including:
JSON RPC method resources: https://getblock.io/docs/available-nodes-methods/ETH/JSON-RPC/eth_accounts
PostMan Collection: https://getblock.io/docs/get-started/postman-collection