Local Development Access Token

const fetch = require('node-fetch');
const fs = require('fs');
const auth = require('@adobe/jwt-auth');

// The root context of the Assets HTTP API
const ASSETS_HTTP_API = '/api/assets';

// Command line parameters
let params = { };

/**
* Application entry point function
*/
(async () => {
    console.log('Example usage: node index.js aem=https://author-p1234-e5678.adobeaemcloud.com propertyName=metadata/dc:rights "propertyValue=WKND Limited Use" folder=/wknd-shared/en/adventures/napa-wine-tasting file=credentials-file.json' );

    // Parse the command line parameters
    params = getCommandLineParams();

    // Set the access token to be used in the HTTP requests to be local development access token
    params.accessToken = await getAccessToken(params.developerConsoleCredentials);

    // Get a list of all the assets in the specified assets folder
    let assets = await listAssetsByFolder(params.folder);

    // For each asset, update it's metadata
    await assets.forEach(asset => updateMetadata(asset, {
        [params.propertyName]: params.propertyValue
    }));
})();

/**
* Returns a list of Assets HTTP API asset URLs that reference the assets in the specified folder.
*
* https://experienceleague.adobe.com/docs/experience-manager-cloud-service/assets/admin/mac-api-assets.html?lang=en#retrieve-a-folder-listing
*
* @param {*} folder the Assets HTTP API folder path (less the /content/dam path prefix)
*/
async function listAssetsByFolder(folder) {
    return fetch(`${params.aem}${ASSETS_HTTP_API}${folder}.json`, {
            method: 'get',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer ' + params.accessToken // Provide the AEM access token in the Authorization header
            },
        })
        .then(res => {
            console.log(`${res.status} - ${res.statusText} @ ${params.aem}${ASSETS_HTTP_API}${folder}.json`);

            // If success, return the JSON listing assets, otherwise return empty results
            return res.status === 200 ? res.json() : { entities: [] };
        })
        .then(json => {
            // Returns a list of all URIs for each non-content fragment asset in the folder
            return json.entities
                .filter((entity) => entity['class'].indexOf('asset/asset') === -1 && !entity.properties.contentFragment)
                .map(asset => asset.links.find(link => link.rel.find(r => r === 'self')).href);
        });
}

/**
* Update the metadata of an asset in AEM
*
* https://experienceleague.adobe.com/docs/experience-manager-cloud-service/assets/admin/mac-api-assets.html?lang=en#update-asset-metadata
*
* @param {*} asset the Assets HTTP API asset URL to update
* @param {*} metadata the metadata to update the asset with
*/
async function updateMetadata(asset, metadata) {
    await fetch(`${asset}`, {
            method: 'put',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer ' + params.accessToken // Provide the AEM access token in the Authorization header
            },
            body: JSON.stringify({
                class: 'asset',
                properties: metadata
            })
        })
        .then(res => {
            console.log(`${res.status} - ${res.statusText} @ ${asset}`);
        });
}

/**
* Parse and return the command line parameters. Expected params are:
*
* - aem = The AEM as a Cloud Service hostname to connect to.
*              Example: https://author-p12345-e67890.adobeaemcloud.com
* - folder = The asset folder to update assets in. Note that the Assets HTTP API do NOT use the JCR `/content/dam` path prefix.
*              Example: '/wknd-shared/en/adventures/napa-wine-tasting'
* - propertyName = The asset property name to update. Note this is relative to the [dam:Asset]/jcr:content node of the asset.
*              Example: metadata/dc:rights
* - propertyValue = The value to update the asset property (specified by propertyName) with.
*              Example: "WKND Free Use"
* - file = The path to the JSON file that contains the credentials downloaded from AEM Developer Console
*              Example: local_development_token_cm_p1234-e5678.json
*/
function getCommandLineParams() {
    let parameters = {};

    // Parse the command line params, splitting on the = delimiter
    for (let i = 2; i < process.argv.length; i++) {
        let key = process.argv[i].split('=')[0];
        let value = process.argv[i].split('=')[1];

        parameters[key] = value;
    };

    // Read in the credentials from the provided JSON file
    if (parameters.file) {
        parameters.developerConsoleCredentials = JSON.parse(fs.readFileSync(parameters.file));
    }

    console.log(parameters);

    return parameters;
}

async function getAccessToken(developerConsoleCredentials) {s
    if (developerConsoleCredentials.accessToken) {
        // This is a Local Development access token
        return developerConsoleCredentials.accessToken;
    }
}

...
return fetch(`${params.aem}${ASSETS_HTTP_API}${folder}.json`, {
            method: 'get',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer ' + params.accessToken // Provide the AEM access token in the Authorization header
            },
})...