> ## Documentation Index > Fetch the complete documentation index at: https://docs.withflex.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Shipping Rate > Creates a new shipping rate. The rate is a fixed amount denominated in USD. New shipping rates are `active` by default. ## OpenAPI ````yaml /openapi.json post /v1/shipping_rates openapi: 3.1.0 info: title: Flex API description: >- The Flex API powers HSA/FSA payment processing for healthcare commerce: checkout sessions, payment intents, subscriptions, customers, refunds, disputes, and eligibility. Authenticate with your partner API key as a Bearer token. All endpoints are scoped to your partner account, and test mode is fully supported via test API keys. version: 0.1.0 servers: - url: https://api.withflex.com security: - BearerAuth: [] tags: - name: Balance Transactions - name: Captures - name: Checkout Sessions - name: Coupons - name: Customers - name: Disputes - name: Events - name: Exports - name: Files - name: Invoices - name: Letters - name: Orders - name: Payment Intents - name: Payment Links - name: Payouts - name: Prices - name: Products - name: Promo Codes - name: Receipts - name: Refunds - name: Setup Intents - name: Shipping Rates - name: Subscriptions paths: /v1/shipping_rates: post: tags: - Shipping Rates summary: Create Shipping Rate description: >- Creates a new shipping rate. The rate is a fixed amount denominated in USD. New shipping rates are `active` by default. operationId: v1.shipping_rates.create requestBody: description: An envelope wrapping a single shipping rate object. content: application/json: schema: $ref: >- #/components/schemas/ShippingRateBody_for_CreateShippingRateRequest example: shipping_rate: display_name: Example amount: 2500 metadata: order_id: '8842' channel: shopify required: true responses: '200': description: An envelope wrapping a single shipping rate object. content: application/json: schema: $ref: '#/components/schemas/ShippingRateBody_for_V1ShippingRate' example: shipping_rate: shipping_rate_id: fshr_01J9XR8M3K7VZ8N2YB4WJ6T0RA active: false display_name: Example amount: 2500 metadata: order_id: '8842' channel: shopify created_at: '2026-06-15T14:30:00Z' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/HttpErrorOut' example: code: string detail: string '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/HttpErrorOut' example: code: string detail: string '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/HttpErrorOut' example: code: string detail: string '409': description: Conflict content: application/json: schema: $ref: '#/components/schemas/HttpErrorOut' example: code: string detail: string '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' example: detail: - loc: - string msg: string type: string '429': description: Too Many Requests content: application/json: schema: $ref: '#/components/schemas/HttpErrorOut' example: code: string detail: string components: schemas: ShippingRateBody_for_CreateShippingRateRequest: description: An envelope wrapping a single shipping rate object. type: object required: - shipping_rate properties: shipping_rate: $ref: '#/components/schemas/CreateShippingRateRequest' description: The shipping rate. example: shipping_rate: display_name: Example amount: 2500 metadata: order_id: '8842' channel: shopify ShippingRateBody_for_V1ShippingRate: description: An envelope wrapping a single shipping rate object. type: object required: - shipping_rate properties: shipping_rate: $ref: '#/components/schemas/V1ShippingRate' description: The shipping rate. example: shipping_rate: shipping_rate_id: fshr_01J9XR8M3K7VZ8N2YB4WJ6T0RA active: false display_name: Example amount: 2500 metadata: order_id: '8842' channel: shopify created_at: '2026-06-15T14:30:00Z' HttpErrorOut: title: HttpError description: The error response returned when a request cannot be completed. type: object required: - code - detail properties: code: description: A short machine-readable error code identifying the type of error. type: string detail: description: A human-readable explanation of what went wrong. type: string example: code: string detail: string HTTPValidationError: description: The error response returned when request validation fails (HTTP 422). type: object required: - detail properties: detail: description: The list of validation errors, one entry per invalid field. type: array items: $ref: '#/components/schemas/ValidationErrorItem' example: detail: - loc: - string msg: string type: string CreateShippingRateRequest: description: Parameters for creating a shipping rate. type: object required: - amount - display_name properties: display_name: description: >- The name shown to the customer at checkout (e.g., `Standard Shipping`). Must be at least 2 characters. type: string minLength: 2 example: Example amount: description: >- The shipping cost, in the smallest currency unit (e.g., `500` = $5.00 USD). Charged in USD. type: integer format: int32 example: 2500 metadata: description: >- Set of key-value pairs you can attach to the shipping rate for storing additional structured information. type: - object - 'null' example: order_id: '8842' channel: shopify example: display_name: Example amount: 2500 metadata: order_id: '8842' channel: shopify V1ShippingRate: description: >- A ShippingRate represents a fixed shipping cost you can apply to a checkout session. Each shipping rate is denominated in USD. type: object required: - active - amount - created_at - display_name - shipping_rate_id properties: shipping_rate_id: description: Unique identifier for the shipping rate. type: string example: fshr_01J9XR8M3K7VZ8N2YB4WJ6T0RA active: description: >- Whether the shipping rate can be applied to new checkout sessions. Defaults to `true` on creation; set to `false` to archive it. type: boolean example: false display_name: description: >- The name shown to the customer at checkout (e.g., `Standard Shipping`). type: string example: Example amount: description: >- The shipping cost, in the smallest currency unit (e.g., `500` = $5.00 USD). Always in USD. type: integer format: int32 example: 2500 metadata: description: >- Set of key-value pairs you can attach to the shipping rate for storing additional structured information. Omitted when no metadata is set. type: - object - 'null' example: order_id: '8842' channel: shopify created_at: $ref: '#/components/schemas/Timestamptz' description: >- Time at which the shipping rate was created, as an RFC 3339 timestamp. example: '2026-06-15T14:30:00Z' example: shipping_rate_id: fshr_01J9XR8M3K7VZ8N2YB4WJ6T0RA active: false display_name: Example amount: 2500 metadata: order_id: '8842' channel: shopify created_at: '2026-06-15T14:30:00Z' ValidationErrorItem: description: >- Validation errors have their own schema to provide context for invalid requests eg. mismatched types and out of bounds values. There may be any number of these per 422 UNPROCESSABLE ENTITY error. type: object required: - loc - msg - type properties: loc: description: >- The location as a [`Vec`] of [`String`]s -- often in the form `["body", "field_name"]`, `["query", "field_name"]`, etc. They may, however, be arbitarily deep. type: array items: type: string msg: description: The message accompanying the validation error item. type: string type: description: >- The type of error, often "type_error" or "value_error", but sometimes with more context like as "value_error.number.not_ge" type: string example: loc: - string msg: string type: string Timestamptz: description: >- A timestamp encoded as an RFC 3339 / ISO 8601 string (e.g. `2026-06-15T14:30:00Z`). type: string example: string securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: API Key description: Use a Bearer token to access this API. ````