Price Publisher

Retrieves prices from CoinMarketCap and publishes them on interval basis.

Prerequisites

• Go (v1.21)+

Flags and Environment Variables

Environment Variable	Description
NATS_URLS	DL NATS broker hosts URLs. Default: nats://europe-west3-gcp-dl-testnet-brokernode-frankfurt01.synternet.com
NATS_NKEY	DL NATS publisher access token.
NATS_PREFIX_NAME	DL publisher stream prefix name. syntropy results in: syntropy.<pub-name>.all. Default syntropy_defi.
NATS_PUB_NAME	DL publisher stream publisher name. price results in: <sub-name>.price.all. Default price.
CMC_IDS	Comma separated list of CoinMarketCap tokens ids (e.g.: 825,3408,12220,3794,22861,21420,21686,7226,13678,7431,1027,3717).
CMC_IDS_SINGLE	Comma separated list of CoinMarketCap tokens ids (e.g.: 825,3408,12220,3794,22861,21420,21686,7226,13678,7431,1027,3717). to publish separately
CMC_API_KEY	CoinMarketCap API key.
PUBLISH_INTERVAL_SEC	Prices publish interval in seconds. Default: 5 seconds.

CMC_IDS

CMC_IDS can be determined by running

curl -L 'https://pro-api.coinmarketcap.com/v1/cryptocurrency/map?symbol=USDT,USDC,OSMO,ATOM,TIA,AxlUSDC,STATOM,INJ,PICA,AKT,ETH,WBTC' -H 'X-CMC_PRO_API_KEY: {{API_KEY}}' -H 'Accept: */*' | jq .

{{LIST_OF_SYMBOLS}} - list of symbols, e.g.: USDT,USDC,OSMO,ATOM,TIA,AxlUSDC,STATOM,INJ,PICA,AKT,ETH,WBTC.

{{API_KEY}} - CMC API key. Retrieve from https://pro.coinmarketcap.com/account. Make sure you have appropriate CMC license.

Note: it is possible to map jq ids and join them, e.g.: jq -r '.data | map(.id) | join(",")', but /map?symbol= can contain multiple entries for same symbol, so cherry-picking is required anyway.

Makefile

Build from source

make build

Live reload

make watch

Format

make fmt

Docker

Build from source

1. Build image.

docker build -f ./docker/Dockerfile -t price-publisher .

2. Run container with passed environment variables.

docker run -it --rm --env-file=.env price-publisher