> ## Documentation Index > Fetch the complete documentation index at: https://docs.cnaught.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Checkout Session > Creates a Checkout Session that, when completed, will result in an order for the specified amount of carbon credits (in kilograms). The total price must be at least $0.50 (the corresponding amount will depend on the per kg price of the specified portfolio). The Quotes API can be used to check the price before attempting to create a session. ## OpenAPI ````yaml api-reference/openapi.yaml post /checkout/sessions openapi: 3.1.0 info: title: CNaught Carbon Credits API Documentation contact: email: support@cnaught.com name: CNaught url: https://cnaught.com/ version: v1 description: | Carbon Credits API Documentation termsOfService: https://cnaught.com/terms license: name: MIT url: https://spdx.org/licenses/MIT.html servers: - url: https://api.cnaught.com/v1 description: CNaught API security: - ApiKey: [] tags: - name: Orders description: Endpoints for placing orders and retrieving information about orders - name: Quotes description: Endpoints for obtaining price quotes for orders - name: Climate Impact description: >- Endpoints for retrieving climate impact data and hosted public impact page configuration - name: Subaccounts description: Endpoints for creating and retrieving information about subaccounts paths: /checkout/sessions: post: tags: - Checkout Sessions summary: Create Checkout Session description: > Creates a Checkout Session that, when completed, will result in an order for the specified amount of carbon credits (in kilograms). The total price must be at least $0.50 (the corresponding amount will depend on the per kg price of the specified portfolio). The Quotes API can be used to check the price before attempting to create a session. operationId: CreateCheckoutSession parameters: - $ref: '#/components/parameters/SubaccountId' description: >- The Subaccount the Checkout Session will create an order for when successfully completed requestBody: description: Checkout Session Parameters required: true content: application/json: schema: $ref: '#/components/schemas/CheckoutSessionParams' examples: Example: value: amount_kg: 100 success_url: >- https://www.example.com/confirmation?my_query=my_value&session_id={CHECKOUT_SESSION_ID} cancel_url: https://www.example.com/purchase-credits description: on behalf of Jane Smith notification_config: url: https://www.example.com/callback responses: '201': description: Checkout Session headers: Location: schema: type: string description: URL for retrieving the Checkout Session examples: - https://api.cnaught.com/v1/checkout/sessions/zpQ6QSNRQh content: application/json: schema: $ref: '#/components/schemas/CheckoutSession' examples: New Checkout Session: value: id: zpQ6QSNRQh amount_kg: 100 price_usd_cents: 200 success_url: >- https://www.example.com/confirmation?my_query=my_value&session_id={CHECKOUT_SESSION_ID} cancel_url: https://www.example.com/purchase-credits checkout_url: https://checkout.cnaught.com/pay/zpQ6QSNRQh state: open created_on: '2022-07-31T18:00:00.000000Z' expires_on: '2022-08-01T18:00:00.000000Z' completed_on: null portfolio_id: mHvNvWbq order_description: on behalf of Jane Smith order_webhook_url: https://www.example.com/callback '400': description: Bad Request content: application/problem+json: schema: $ref: '#/components/schemas/BadRequestProblemDetails' example: errors: amount_kg: - '''amount_kg'' must be greater than 0' type: https://api.cnaught.com/v1/errors/invalid-parameters title: Your request parameters didn't validate status: 400 '401': $ref: '#/components/responses/Unauthorized' components: parameters: SubaccountId: name: X-Subaccount-Id in: header required: false description: >- If present, scopes the operation to the subaccount with given id. See [Subaccounts](/api/reference/#tag/Subaccounts) for more info. schema: type: string schemas: CheckoutSessionParams: type: object required: - amount_kg - success_url - cancel_url properties: amount_kg: type: number description: >- Amount of carbon credits to be purchased upon checkout completion, in kilograms examples: - 100 success_url: type: string description: > The URL the customer will be redirected to after the payment is completed. The `{CHECKOUT_SESSION_ID}` template can be used to include the session id in a query parameter. Make sure to include the template exactly as `{CHECKOUT_SESSION_ID}` (i.e. do not replace it with the actual session id). examples: - https://www.example.com/confirmation - >- https://www.example.com/confirmation?session_id={CHECKOUT_SESSION_ID} - >- https://www.example.com/confirmation?my_query=my_value&session_id={CHECKOUT_SESSION_ID} cancel_url: type: string description: >- The URL the customer will be directed to if they decide to cancel payment and return to your website examples: - https://www.example.com/purchase-credits portfolio_id: type: - string - 'null' description: > Optional id of the portfolio to use for fulfilling the order resulting from the Checkout Session. If not specified, the user or subaccount's default portfolio will be used (depending on if a subaccount is provided). examples: - a23bF6 description: type: - string - 'null' description: >- Optional public description for the order that will be shown on the certificate, as provided when order was placed maxLength: 512 examples: - on behalf of Jane Smith notification_config: $ref: '#/components/schemas/NotificationConfig' CheckoutSession: type: object properties: id: type: string description: Identifier that can be used to retrieve the Checkout Session examples: - zpQ6QSNRQh amount_kg: type: number description: >- Amount of carbon credits to be purchased upon checkout completion, in kilograms examples: - 10.5 price_usd_cents: type: number description: Total price to be charged upon checkout completion, in USD cents examples: - 2350 success_url: type: string description: URL the customer will be redirected to after they complete Checkout. examples: - https://www.example.com/purchase/success cancel_url: type: string description: >- URL the customer will be redirected to if they click the "back" button in Checkout. examples: - https://www.example.com/purchase checkout_url: type: string description: >- URL to the Checkout Session. Redirect the customer to this URL to take them to Checkout. examples: - https://checkout.cnaught.com/pay/zpQ6QSNRQh state: type: string description: > The status of the Checkout Session, one of `open`, `complete`, or `expired`. * `open` - The checkout session is still in progress. Payment processing has not started. * `complete` - The checkout session is complete. Payment processing may still be in progress. * `expired` - The checkout session has expired. No further processing will occur. expires_on: type: string description: Timestamp of when the session will expire. completed_on: type: - string - 'null' description: >- Timestamp of when the session was completed. Null if session has not been completed. portfolio_id: type: string description: >- Id of the portfolio the customer will purchase from when completing Checkout. subaccount_id: type: - string - 'null' description: Id of the subaccount associated with the customer order_description: type: - string - 'null' description: >- Description to be associated with the order created from this session. order_webhook_url: type: - string - 'null' description: Webhook URL for updates to the order created from this session. BadRequestProblemDetails: allOf: - $ref: '#/components/schemas/BaseProblemDetails' - type: object properties: errors: description: >- Invalid properties object where each property is the key, mapped to a list of reasons why the property is invalid type: - object - 'null' additionalProperties: type: array items: type: string NotificationConfig: type: - object - 'null' description: | Optional configuration for a callback url to invoke with updates when the status of an order changes. required: - url properties: url: type: string description: callback url to invoke when status of the order changes maxLength: 2048 examples: - https://www.example.com/callback BaseProblemDetails: type: object description: Problem details object returned on errors properties: title: type: string description: Short, human-readable summary of the problem details: type: string description: Longer, human-readable description of the problem type: type: string description: URI that identifies the problem type status: type: integer description: HTTP status code of the error responses: Unauthorized: description: Request Unauthorized content: application/problem+json: schema: properties: title: type: string description: Short, human-readable summary of the problem type status: type: integer description: HTTP status code of the error example: title: Authorization has been denied for this request status: 401 securitySchemes: ApiKey: type: http scheme: bearer ````