A minimal JavaScript SDK for interacting with Blockmason Link.

link-sdk.js

const link = (options = {}) => {
  const {
    baseUrl = 'https://api.block.mason.link',
    clientId,
    clientSecret
  } = options;

  if (!clientId || !clientSecret) {
    throw new Error('Missing options.clientId or options.clientSecret');
  }

  const toQueryString = (inputs = {}) => {
    const pairs = [];
    const keys = Object.keys(inputs);

    for (const key of keys) {
      const { [key]: value } = inputs;
      pairs.push(`${encodeURIComponent(key)}=${encodeURIComponent(value)}`);
    }

    if (pairs.length > 0) {
      return `?${pairs.join('&')}`;
    }

    return '';
  };

  const credential = {};

  const authenticate = async () => {
    if (credential.accessToken) {
      return Promise.resolve(credential.accessToken);
    }

    const response = await fetch(`${baseUrl}/oauth2/token`, {
      body: JSON.stringify(credential.refreshToken ? {
        grant_type: 'refresh_token',
        refresh_token: credential.refreshToken
      } : {
        client_id: clientId,
        client_secret: clientSecret,
        grant_type: 'client_credentials'
      }),
      headers: { 'Content-Type': 'application/json' },
      method: 'POST'
    });

    const { access_token, errors, refresh_token } = await response.json();

    if (errors && errors.length > 0) {
      throw new Error(errors.map((error) => error.detail).join(' '));
    }

    Object.assign(credential, { accessToken: access_token, refreshToken: refresh_token });

    return credential.accessToken;
  };

  return {
    get: async (path = '/', inputs = {}) => {
      const accessToken = await authenticate();
      const response = await fetch(`${baseUrl}/v1${path}${toQueryString(inputs)}`, { headers: { Authorization: `Bearer ${accessToken}` }, method: 'GET' });
      const outputs = await response.json();
      return outputs;
    },

    post: async (path = '/', inputs = {}) => {
      const accessToken = await authenticate();
      const response = await fetch(`${baseUrl}/v1${path}`, {
        body: JSON.stringify(inputs),
        headers: {
          Authorization: `Bearer ${accessToken}`,
          'Content-Type': 'application/json'
        },
        method: 'POST'
      });
      const outputs = await response.json();
      return outputs;
    }
  };
};

Usage:

const { message } = await link({ clientId: '<your-client-id>', clientSecret: '<your-client-secret>' }).get('/sayHello');
console.log(message);
// => "Hello, world!"