elyx0/btc-kalichkin-nvt-fetcher

Fetches the current network value to transactions (NVT) of the BTC market using character recognition on a canvas element

Simple Kalichkin NVT Fetcher for BTC market

The Network Value to Transactions (NVT) ratio measures the dollar value of cryptoasset transaction activity relative to network value. This is a simple way to compare how the market prices one unit of on-chain transactions across different networks.

Generally speaking, a “low” market to transaction value denotes an asset which is more cheaply valued per unit of on-chain transaction volume.

Network value consists of the total market value of all tokens in circulation. The transaction element is an estimate of the value of on-chain transaction activity drawn from block explorers and blockchains.

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How does it work

The code is build with Typescript

• It fetches the queries from sqlite3 database

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• It uses chrome headless with puppeteer to grab the canvas rendered screenshot at the last interval

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• enlarges it with sharp then

• extracts the text from tesseract image recognition models

• Saves it into history table

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• sends the results by email using mailgun

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Development

You will need the following env vars or using a .env file:

PORT=8888
MAILGUN_API_KEY=239e8293e72398whateverwhatever
MAILGUN_DOMAIN=sandbox23892y3e82whatever.mailgun.org
[email protected]

• Edit the seed.ts to your liking

Then after npm install install run once: npm run seed

Locally:

npm install && npm run build && npm run fastLocal

To get the code coverage: npm run coverage

To run the tests in watch mode: npm run watch

Debugging

.vscode launch options are provided for debugging locally

On Docker:

• Build the image: npm run docker-build
• Run the image: npm run docker-run

Alternatively: docker-compose up

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Ideally run on a daily basis with cron, ex: 2am every day:

0 2 * * * /usr/local/node /your/code/path/build/server.js

Ex on my mac local:

* 2 * * * /usr/local/bin/node /Sites/nvt/build/server.js >> /Sites/nvt/cron.log 2>&1