Nstream Stock Demo

A tutorial application for teaching core Swim concepts. See a hosted version of this app running at https://stocks-live.nstream-demo.io.

Introduction

This example utilizes a 3rd party data service called TwelveData to provide realtime data about the stock market. In order to run this example you will need an api key for TwelveData.

Running the example

Replace the following token with your token to TwelveData.

cd server
TOKEN=asdfaerraxcsasdfa mvn clean compile exec:java

Viewing the UI

Swim UI Framework

We have two versions of a UI available. The first is built with React + TypeScript + Vite, and uses AG Grid for the table component.

cd ui
npm install
npm run dev

Then head to localhost:5173 to see it in action.

Swim UI Framework

The other option is a UI built with NStream's own UI framework.

cd nstream-ui
npm install
TOKEN=asdfaerraxcsasdfa npm run dev

Then head to localhost:9001 to see it in action.

Streaming APIs

The swim-cli is the simplest way to fetch or stream data from the web agents in this application

"swim-cli" installation

swim-cli installation details available here: https://www.swimos.org/backend/cli/

Application APIs

Note:

• Below swim-cli commands for introspection are for streaming locally running application.
• There is a hosted version of this application running here: https://stocks-live.nstream-demo.io/
• To stream APIs for the hosted version, replace warp://localhost:9001 in below commands with warps://stocks-live.nstream-demo.io

(Below, Stock ticker symbol "AAPL" is used as an example)

1. SYMBOLS:

• List of various stocks' current price, trading volume, bid/ask if any, and the price movement in the stock price.

swim-cli sync -h warp://localhost:9001 -n /symbols -l stocks

2. STOCK:

• A particular stock's current status details (current price, trading volume, bid/ask if any, and the price movement in the stock price)

swim-cli sync -h warp://localhost:9001 -n /stock/AAPL -l status

• A particular stock's previous close price details

swim-cli sync -h warp://localhost:9001 -n /stock/AAPL -l previousClose

Introspection APIs

The Swim runtime exposes its internal subsystems as a set of meta web agents.

Use the swim:meta:host agent to introspect a running host. Use the pulse lane to stream high level stats:

swim-cli sync -h warp://localhost:9001 -n swim:meta:host -l pulse

The nodes lane enumerates all agents running on a host:

swim-cli sync -h warp://localhost:9001 -n swim:meta:host -l nodes

The fragment part of the nodes lane URI can contain a URI subpath filter:

swim-cli sync -h warp://localhost:9001 -n swim:meta:host -l nodes#/

Node Introspection

You can stream the utilization of an individual web agent:

swim-cli sync -h warp://localhost:9001 -n swim:meta:node/%2fadapter%2ftwelvedata -l pulse

swim-cli sync -h warp://localhost:9001 -n swim:meta:node/%2fsymbols -l pulse

swim-cli sync -h warp://localhost:9001 -n swim:meta:node/%2fstock%2fAAPL -l pulse

And discover its lanes:

swim-cli sync -h warp://localhost:9001 -n swim:meta:node/%2fadapter%2ftwelvedata -l lanes

swim-cli sync -h warp://localhost:9001 -n swim:meta:node/%2fsymbols -l lanes

swim-cli sync -h warp://localhost:9001 -n swim:meta:node/%2fstock%2fAAPL -l lanes

Mesh introspectiong

swim-cli sync -h warp://localhost:9001 -n swim:meta:edge -l meshes