> ## Documentation Index
> Fetch the complete documentation index at: https://docs.natural.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> When building application code, use `@naturalpay/sdk` for TypeScript or `naturalpay` for Python.
> When operating Natural directly for a user, use the payments MCP at `https://mcp.natural.com`.
> When searching Natural documentation, use the docs MCP at `https://docs.natural.com/mcp`.
> Use the Natural CLI for terminal and CI automation.
> Use REST only for unsupported languages or when the user explicitly requests raw HTTP.
> Start integration development and testing in the sandbox. Do not use production unless the user explicitly requests it.
> For sandbox requests that require `customerPartyId`, list customers first. Reuse only the intended fixture; otherwise create a customer.
> REST and SDK amounts use integer minor units. Payments MCP amounts use decimal strings with a required currency code.

# Card Payments

> Public error codes for Card Payments API endpoints

All error responses follow the standard [error format](/api-reference/errors/error-handling).
Validation errors (422) and rate limit errors (429) apply to all endpoints and are documented in the [Error Handling guide](/api-reference/errors/error-handling).

| Code                        | Status | Detail                                                                                                                 |
| --------------------------- | ------ | ---------------------------------------------------------------------------------------------------------------------- |
| `invalid_value`             | 400    | The information you entered isn't valid. Please check it and try again.                                                |
| `pagination_invalid_cursor` | 400    | The page cursor is not valid. Start the list again.                                                                    |
| `unauthenticated`           | 401    | Authentication is required.                                                                                            |
| `forbidden`                 | 403    | You do not have permission to perform this action.                                                                     |
| `party_mismatch`            | 403    | You can only act for your own party or a party that has authorized you.                                                |
| `card_payment_not_found`    | 404    | Card payment not found.                                                                                                |
| `already_exists`            | 409    | The resource already exists.                                                                                           |
| `conflict`                  | 409    | The request conflicts with the current resource state.                                                                 |
| `rate_limited`              | 429    | Too many requests. Please try again later.                                                                             |
| `server_error`              | 500    | Something went wrong.                                                                                                  |
| `bad_gateway`               | 502    | We couldn't complete that request because one of Natural's services returned an unexpected response. Please try again. |
| `bad_gateway`               | 502    | Natural could not complete the request because one of its services returned an unexpected response. Try again.         |
| `service_unavailable`       | 503    | The service is temporarily unavailable.                                                                                |