> ## Documentation Index > Fetch the complete documentation index at: https://docs.streamlinedpayments.com/llms.txt > Use this file to discover all available pages before exploring further. # List top customers > Find the customers who bought the most or paid you the most in a date range, largest first. Defaults to the last six months, including this one. ## OpenAPI ````yaml /api-reference/openapi.yaml get /reports/top_customers openapi: 3.0.3 info: title: Streamlined API description: > Access customers, customer applications, customer groups, products, payouts, invoices, transactions, deposit links, and the reports behind your dashboard programmatically through this API, and receive webhooks when deposit links change. All requests must be authenticated with an API key. version: 1.8.0 license: name: Proprietary url: https://streamlinedpayments.com/terms servers: - url: https://api.staging.streamlinedpayments.com/api/v1 description: Sandbox - url: https://api.streamlinedpayments.com/api/v1 description: Production security: - AppIdAuth: [] ApiKeyAuth: [] tags: - name: Customers description: Create, update and delete the businesses you sell to. - name: Customer applications description: >- List the applications your customers submit, and approve them. Approving can also set net terms and export the customer to Shopify. See [Approve customer applications](/guides/customer-applications). - name: Customer groups description: >- Organize customers into groups and manage who's in each one. A group can be linked to a Shopify B2B company. - name: Customer files description: Upload and manage files attached to a customer. - name: Customer addresses description: Manage a customer's addresses and choose their default billing address. - name: Orders description: Create orders, add and remove line items, and schedule them. - name: Invoices description: Create invoices from orders, then list, look up and update them. - name: Transactions description: List transactions and look one up. - name: Payouts description: List payouts, including pending ones, and look one up. - name: Products description: >- Create and update the products and services you sell, import them in bulk, and merge duplicates. - name: Deposit links description: Collect money from a customer before an invoice exists. - name: Webhooks description: >- Register HTTPS endpoints to receive events when something changes. See [Webhooks](/guides/webhooks) for signatures, retries and delivery guarantees. - name: Reports description: >- Read the aging, sales, collections, and customer figures your dashboard and customer pages show. Amounts are in cents, in the currency each response names. See [Reports](/guides/reports) for how each figure is worked out. paths: /reports/top_customers: get: tags: - Reports summary: List top customers description: >- Find the customers who bought the most or paid you the most in a date range, largest first. Defaults to the last six months, including this one. operationId: listTopCustomers parameters: - name: basis in: query required: false description: >- `sales` ranks by invoices issued in the range. `cash` ranks by payments received in it. schema: type: string enum: - sales - cash default: sales - name: start_date in: query required: false description: >- First day of the range, as `YYYY-MM-DD`. The range can be at most 24 months. schema: type: string format: date - name: end_date in: query required: false description: Last day of the range, as `YYYY-MM-DD`. schema: type: string format: date - $ref: '#/components/parameters/ReportPage' - $ref: '#/components/parameters/ReportPerPage' responses: '200': description: Successful operation content: application/json: schema: $ref: '#/components/schemas/TopCustomers' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' components: parameters: ReportPage: name: page in: query description: Page number, from 1 to 10000. required: false schema: type: integer default: 1 minimum: 1 maximum: 10000 ReportPerPage: name: per_page in: query description: Number of rows per page, from 1. Values above 100 are treated as 100. required: false schema: type: integer default: 20 minimum: 1 schemas: TopCustomers: type: object properties: currency: $ref: '#/components/schemas/Currency' basis: type: string enum: - sales - cash description: What the list ranks by, as sent. customer_count: type: integer description: Number of customers with an amount in the range, across every page. example: 86 total: type: integer description: >- Every customer's amount in the range, in cents. Matches Get monthly sales and payments for the same months. example: 511000000 data: type: array items: allOf: - $ref: '#/components/schemas/ReportCustomer' - type: object properties: amount: type: integer description: In cents. example: 107000000 share: type: number nullable: true description: >- The customer's share of `total`, as a fraction from 0 to 1. example: 0.21 meta: $ref: '#/components/schemas/PaginationMeta' Currency: type: string description: >- ISO currency code. Most resources support these. Products are limited to USD, CAD, EUR, GBP, AUD. enum: - USD - CAD - GBP - EUR - AUD - JPY - INR ReportCustomer: type: object properties: uuid: type: string format: uuid description: The customer's UUID. name: type: string description: The customer's name. example: Harbor Foods PaginationMeta: type: object properties: current_page: type: integer per_page: type: integer total_pages: type: integer total_count: type: integer Error: type: object properties: error: type: string message: type: string responses: BadRequest: description: >- A parameter is malformed, out of range, or not one of its allowed values (`invalid_parameter`). `message` says which. Values aren't ignored, except that `per_page` above 100 is treated as 100. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: invalid_parameter message: weeks must be one of 13, 26, 52 Unauthorized: description: Authentication failed content: application/json: schema: $ref: '#/components/schemas/Error' examples: AuthenticationRequired: value: error: Authentication required message: >- API endpoint requires authentication. Please provide valid X-App-Id and X-Api-Key headers. InvalidCredentials: value: error: Invalid credentials message: >- The provided API credentials are invalid. Please check your X-App-Id and X-Api-Key values. securitySchemes: AppIdAuth: type: apiKey in: header name: X-App-Id description: App ID for authentication ApiKeyAuth: type: apiKey in: header name: X-Api-Key description: API Key for authentication ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.