Blockchain microservice architecture

Overview

The blockchain microservice is split into a websocket server and a REST API server that provide all communication with a node. The implementation of the microservice should be opaque to the backend, it should merely need to communicate over the documented endpoints and websocket messages.

Websocket Server

A websocket server provides real-time information on contributions. All business logic is separated by notifiers which have their own namespace and set of messages for sending and receiving. All websocket messages are formatted redux style, like so:

{
  "type": "namespace:type",
  "payload": { /* anything */ }
}

The notifiers and their message types are as follows:

Contribution

SEND contribution:confirmation

{
  to: string; // The address it was sent to
  amount: string; // The amount that was sent, in base unit
  txid: string; // The transaction id for the send
  memo: string; // The attached memo, can be empty string
  contributionId: number; // The contribution id this maps to
}

REST API

An Express REST API is provided to allow for request-response interactions from the backend. Rather than piggy-back on the websocket server, the REST API is for when information sent to the microservice needs validation with the node, or requires a semi-immediate response. The API is authenticated using the same secret key as the websocket server in the Authorization header. The endpoints are as follows:

GET /contributions/addresses

Parameters:

• contributionId (number) - The numeric contribution ID from the backend. Must be numeric, since it will be used as address derivation index.

Response:

{
  "data": {
    "transparent": "tm5vA...",
    "sprout": "ztJa4..."
  }
}

Errors:

• 500 if there's a failure with node communication

POST /contributions/disclosure

Parameters:

• disclosure (string) - Hex disclosure from z_getpaymentdisclosure.

Response:

{
  "data": {
    "valid": true
  }
}

Errors:

• 400 if the disclosure is missing / incorrect format
• 500 if there's a failure with node communication