mkdir like-nodewatch
cd like-nodewatch
npm init #全部適当
npm install express axios
touch app.js

app.js

const express = require('express');
const axios = require('axios');

const app = express();
const port = 3030;
const apiNode = 'http://localhost:3000'

app.get('/api/symbol/height', async (req, res) => {
    try {
        const response = await axios.get(`${apiNode}/chain/info`);
        const data = response.data;
        const height = parseInt(data.height, 10);
        const finalizedHeight = parseInt(data.latestFinalizedBlock.height, 10);

        res.json({
            finalizedHeight,
            height
        });
    } catch (error) {
        console.error('Error fetching chain info:', error);
        res.status(500).send('Error fetching chain info');
    }
});

app.get('/api/symbol/nodes/peer', async (req, res) => {
    try {
        const chRes = await axios.get(`${apiNode}/chain/info`);
        const chData = chRes.data;
        const height = parseInt(chData.height, 10);
        const finalizedHeight = parseInt(chData.latestFinalizedBlock.height, 10);

        const niRes = await axios.get(`${apiNode}/node/info`);
        const niData = niRes.data;
        const mainPublicKey = niData.publicKey;
        const nodePublicKey = niData.nodePublicKey;
        const name = niData.friendlyName;
        const roles = niData.roles;
        const endpoint = `http://${niData.host}:3000`;

        const npRes = await axios.get(`${apiNode}/network/properties`);
        const npData = npRes.data;
        const currencyMosaicId = npData.chain.currencyMosaicId
            .replace(/'/g, '')
            .replace(/^0x/, ''); 

        const aiRes = await axios.get(`${apiNode}/accounts/${mainPublicKey}`);
        const aiData = aiRes.data;
        const mosaic = aiData.account.mosaics.find(m => m.id === currencyMosaicId);

        let balance = 0;
        if (mosaic) {
            const amountAsBigInt = BigInt(mosaic.amount);
            balance = Number(amountAsBigInt) / 1000000;
        }

        res.json([{
            balance,
            endpoint,
            finalizedHeight,
            height,
            mainPublicKey,
            name,
            nodePublicKey,
            roles
        }]);
    } catch (error) {
        console.error('Error fetching chain info:', error);
        res.status(500).send('Error fetching chain info');
    }
});

app.get('/api/symbol/nodes/api', async (req, res) => {
    try {
        res.json([])
    }
    catch (error) {
        console.error('Error fetching chain info:', error);
        res.status(500).send('Error fetching chain info');
    }
})

app.listen(port, () => {
    console.log(`Server is running on port ${port}`);
});

nohup node app.js &

最後にshoestringのconfigファイル

mainnet.ini

[services]
nodewatch = http://localhost:3030

これでいけるような気がするけど環境がないので一切試してない！