---
title: Add review requirement
description: Add a review requirement to a checkout based on the cart total.
source_url:
  html: 'https://shopify.dev/docs/apps/build/checkout/payments/review-requirements'
  md: 'https://shopify.dev/docs/apps/build/checkout/payments/review-requirements.md'
---

# Add review requirement

A review requirement enables you to control whether an order is submitted as a [draft](https://shopify.dev/docs/apps/build/b2b/draft-orders) for review. This tutorial shows you how to use the `orderReviewAdd` operation in the [Payment Customization API](https://shopify.dev/docs/api/functions/reference/payment-customization#CartPaymentMethodsTransformRunResult.fields.operations.orderReviewAdd) to dynamically add a review requirement during checkout based on business rules.

***

## What you'll learn

In this tutorial, you'll learn foundational concepts and techniques for customizing checkout behaviour using Shopify Functions and the [Payment Customization API](https://shopify.dev/docs/api/functions/latest/payment-customization).

* How to query and use cart data in a function's input to drive decisions.
* Conditionally using operations (such as `orderReviewAdd`) to modify checkout flows, including creating draft orders for review.
* Testing and validating function logic in development environments.

![A B2B checkout with a review requirement](https://shopify.dev/assets/assets/images/apps/checkout/b2b-checkout-with-review-requirement-BBucxTBQ.png)

***

## Requirements

* You've completed at least the first tutorial in this [series](https://shopify.dev/docs/apps/build/checkout/payments#tutorial-series).

***

## Step 1: Configure the function

First, start a developement server if you haven't already (see [CLI reference](https://shopify.dev/docs/api/shopify-cli/app/app-dev)):

## terminal

```terminal
shopify app dev
```

In this example, a review requirement is added based on the cart total. You'll implement the following behaviour:

* No review is required for any order where the cart total is less than $5000.

* If the cart total is $5000 or more:

  * B2B orders will checkout as a Draft Order.
  * D2C orders aren't affected (see [limitations](https://shopify.dev/docs/apps/build/checkout/payments#limitations-and-considerations)).

1. Navigate to your function in `extensions/payment-customization`:

   ## Terminal

   ```terminal
   cd extensions/payment-customization
   ```

2. Replace the code in the `src/run.graphql` file with the following code.

   The input query retrieves the [`cart`](https://shopify.dev/docs/api/functions/reference/payment-customization#Input.fields.cart) object, which includes a `cost` object with the total value of the cart.

   The query differs slightly in Rust and JavaScript due to code generation requirements.

   ## run.graphql

   ## src/run.graphql

   ##### Rust input query

   ```graphql
   query Input {
     cart {
       cost {
         totalAmount {
           amount
         }
       }
     }
   }
   ```

   ##### JavaScript input query

   ```graphql
   query RunInput {
     cart {
       cost {
         totalAmount {
           amount
         }
       }
     }
   }
   ```

3. If you're using JavaScript, then run the following command to regenerate types based on your input query:

   ## Terminal

   ```terminal
   shopify app function typegen
   ```

4. Implement business logic for the function to add a review requirement when the cart total exceeds $5000. Replace the contents of`src/run.rs` or `src/run.js` file with the following code:

   ## File

   ## src/run.rs

   ##### Rust

   ```rust
   use crate::schema;
   use shopify_function::prelude::*;
   use shopify_function::Result;

   #[shopify_function]
   fn cart_payment_methods_transform_run(input: schema::cart_payment_methods_transform_run::Input) -> Result<schema::CartPaymentMethodsTransformRunResult> {
     let cart_total: f64 = input.cart().cost().total_amount().amount().as_f64();

     let operations = if cart_total > 5000.0 {
         vec![schema::Operation::OrderReviewAdd(
             schema::OrderReviewAddOperation {
                 reason: "An order over $5000 requires review.".to_string()
             }
         )]
     } else {
         vec![]
     };

     Ok(schema::CartPaymentMethodsTransformRunResult { operations })
   }
   ```

   ##### JavaScript

   ```javascript
   // @ts-check

   /**
   * @typedef {import("../generated/api").RunInput} RunInput
   * @typedef {import("../generated/api").FunctionRunResult} FunctionRunResult
   */

   /**
   * @type {FunctionRunResult}
   */

   /**
   * Sets payment terms based on cart total and buyer identity
   * @param {RunInput} input - Function input
   * @returns {FunctionRunResult} Function result with operations to apply
   */
   export function run(input) {

     const operations = [];
     const totalAmount = input.cart.cost.totalAmount.amount;

     if (totalAmount > 5000) {
       operations.push({
         orderReviewAdd: {
           reason: "An order over $5000 requires review."
         }
       });
     }
     return { operations };
   }
   ```

***

## Step 2: Test the payment customization

Test how the review requirement is added based on the cart total.

### Test with a B2B checkout with a cart total under $5000

1. Open your dev store and log in as a B2B customer.
2. Build a cart with a total (including shipping and tax) under $5000.
3. The review requirement threshold is not met in this scenario. Verify that the function does not add a review requirement.
4. Complete the checkout and verify an order is created.

![B2B checkout with cart total under $5000 showing no review requirement](https://shopify.dev/assets/assets/images/apps/checkout/b2b-checkout-with-no-function-run-D4dLLOKx.png)

### Test with a B2B checkout with a cart total over $5000

1. Open your dev store and log in as a B2B customer.
2. Build a cart with a total (including shipping and tax) over $5000.
3. Since the review requirement threshold is met, verify that the function adds a review requirement.
4. Submit the checkout for review and verify a Draft Order is created as a result.

![B2B checkout with cart total over $5000 showing review requirement and submit for review option](https://shopify.dev/assets/assets/images/apps/checkout/b2b-checkout-with-function-run-udS44zqY.png)

### Test with a direct-to-consumer checkout

1. Open your dev store and log in as a direct-to-consumer customer.
2. Build a cart with a total (including shipping and tax) over $5000.
3. Since review requirements aren't [applicable to D2C checkouts](https://shopify.dev/docs/apps/build/checkout/payments#limitations-and-considerations), the function doesn't add a review requirement.
4. Verify that the checkout is not modified, and can be completed as normal.

![Direct-to-consumer checkout with cart total over $5000 showing no review requirement](https://shopify.dev/assets/assets/images/apps/checkout/d2c-no-review-requirement-DqjbGrBK.png)

***

## Next steps

* Build a [payment customization user interface](https://shopify.dev/docs/apps/build/checkout/payments/build-ui) with App Bridge.
* Learn how to use [variables](https://shopify.dev/docs/apps/build/functions/input-queries/use-variables-input-queries) in your input query.
* Explore more [payment customization options](https://shopify.dev/docs/api/functions/reference/payment-customization) in the API reference.

***