How to Save Passes to Google Pay using Nodejs?

Question

I want to use google pay API for passes with firebase cloud functions, but unfortunately, nodejs is bitterly missed in google-pay/passes-rest-samples and is not supported in the client libraries.

I was able to test the API in the PHP sample - that is my service account is up and linked to my merchant account, but I want to know how to use the API in nodejs:

1- How to get an access token and save a pass in the request call?

Tried the following but I'm always getting 401 status code:

a) Using google-auth-library-nodejs

    // Create a new JWT client using the key file downloaded from the Google Developer Console
      const auth = new google.auth.GoogleAuth({
          keyFile: path.join(__dirname, 'serviceAccount.json'),
          scopes: 'https://www.googleapis.com/auth/wallet_object.issuer',
      });
      const client = await auth.getClient();
      const accessToken = (await client.getAccessToken()).token;

      const result = (await axios.post(`https://walletobjects.googleapis.com/walletobjects/v1/loyaltyClass?strict=true`, payload,
        { headers: { Authorization: `Bearer ${accessToken}` } })
    ).data;
     

b) Using jsonwebtoken

 const token = jwt.sign({ payload, typ: JWT_TYPE }, credentialJson.private_key,
        {
            algorithm: 'RS256',
            audience: AUDIENCE,
            issuer: SERVICE_ACCOUNT_EMAIL_ADDRESS,

        });

Answer 1

Here is an example of how to achieve this with Node.js:

The relevant parts:

// Step 1: create a loyalty object
const loyaltyObject = await createLoyaltyObject();

// Step 2: define jwt claims
const claims = {
  aud: 'google',
  origins: [website],
  iss: credentials.client_email,
  typ: 'savetowallet',
  payload: {
    loyaltyObjects: [
      {
        id: loyaltyObject.id,
      },
    ],
  },
};

// Step 3: create and sign jwt
const token = jwt.sign(claims, credentials.private_key, { algorithm: 'RS256' });