Backend integration overview

Most Grona content runs in your app on the signed configuration alone. Offers that carry money are different. The app cannot prove who may receive an offer or what an order was worth, so your servers do that work. This page lists the four jobs your backend does in a Grona mobile integration and shows how they fit together.

The jobs

Job	When	What your server does
Serve the grant source	When a shopper signs in, and again before their grants expire	Inside the shopper’s authenticated session, fetches their grants from Grona server to server and returns them to the app unchanged
Verify and redeem grants	When an order is placed	Verifies every grant token the app sent, re-checks the campaign’s conditions against the real order, uses each grant once, and applies the value from the verified claims
Report revenue	After orders	Sends order data from your order system, which is the revenue truth for Grona’s analysis
Manage keys	Before each key rotation	Pins Grona’s grant public keys by kid, and adds the next key before Grona signs with it

If your app shows no offers, you need only the revenue job, so that campaigns are measured against real orders.

How the jobs fit together

1. The shopper signs in, and your app calls identify with their opaque customer id, for example cus_7Hq2Lm9x.

2. The SDK calls your app’s grant source, which calls your backend. Your backend calls Grona’s grants endpoint with your workspace secret key and returns the grants to the app. See Grants and order verification.

3. The SDK verifies the grants with the grant keys your app pins and renders the offers they match, for example a weekend offer of 10% off the order.

4. At checkout, your app sends the grant tokens of the active treatments with the order.

5. Your order backend verifies each token, records each grant as used inside the order transaction, and applies the treatment from the verified claims. A failed check means no treatment, and the order still succeeds.

6. Your order system reports the order to Grona. Grona joins it to the app’s events on the order id and the grant’s jti. See Report revenue.

What stays with Grona

• The configuration. Grona signs it and publishes it at your config URL. Your servers neither host nor sign it.
• Eligibility. Grona’s server decides which shopper gets which grant.
• Private keys. Grona holds the private keys that sign configurations, preview pins and grants. You receive only public keys. Grona does not publish them at a URL: it gives them to you, and you pin them. See Rotate signing keys.
• Single use. There is no Grona endpoint that redeems a grant. Your order database enforces single use on jti.

Keys and secrets

Credential	Where it lives	Secret
Workspace key, for example acme-market	In your app	No. It is a public identifier
Config public keys	In your app	No
Grant public keys	In your app and in your order backend	No
Workspace secret key	On your servers only	Yes. Never ship it in the app

See Keys and environments and Authentication.

Note

The mobile SDKs and the grants endpoint are available on request.

Next steps

Grants and order verificationFetch grants for a shopper and verify them when an order is placed, with tested samples.

Report revenueWhy revenue comes from your order system and how it joins to campaign events.

Rotate signing keysRotate config and grant keys without breaking installed apps.