# SmartRetry Documentation

> Official SmartRetry API documentation. Integrate intelligent retry and multi-acquirer routing to recover declined payments.

## Docs

- [Errors](https://www.smartretry.com/docs/api-reference/errors.md): HTTP error codes and reason codes returned by the SmartRetry API.
- [Cancel future transaction](https://www.smartretry.com/docs/api-reference/future-transactions/cancel.md): Cancel a specific scheduled payment within a recurring series without affecting the rest of the schedule.
- [Charge future transaction](https://www.smartretry.com/docs/api-reference/future-transactions/charge.md): Execute a scheduled future payment immediately, before its planned date.
- [Future transaction status](https://www.smartretry.com/docs/api-reference/future-transactions/status.md): Retrieve the details and current status of a single scheduled future payment within a recurring series.
- [Update future transaction](https://www.smartretry.com/docs/api-reference/future-transactions/update.md): Override the amount or reschedule a specific upcoming payment within a recurring series.
- [Health endpoints](https://www.smartretry.com/docs/api-reference/health.md): Check API availability and system status.
- [Idempotency](https://www.smartretry.com/docs/api-reference/idempotency.md): Safe retry behavior for POST payment requests using the Idempotency-Key header.
- [API Overview](https://www.smartretry.com/docs/api-reference/overview.md): Overview of the SmartRetry Terminal API - endpoints, authentication, and request format.
- [Capture](https://www.smartretry.com/docs/api-reference/payments/capture.md): Settle a previously authorized pre-authorization.
- [Pre-authorization](https://www.smartretry.com/docs/api-reference/payments/preauth.md): Reserve funds on a payment instrument without capturing immediately.
- [Refund](https://www.smartretry.com/docs/api-reference/payments/refund.md): Return funds to a customer for a completed sale or capture.
- [Sale](https://www.smartretry.com/docs/api-reference/payments/sale.md): Charge a payment instrument in a single step.
- [Transaction status](https://www.smartretry.com/docs/api-reference/payments/status.md): Retrieve the current status and details of any transaction.
- [Void](https://www.smartretry.com/docs/api-reference/payments/void.md): Cancel a pre-authorization before it is captured.
- [Rate limiting](https://www.smartretry.com/docs/api-reference/rate-limiting.md): Understand API rate limits and implement proper retry logic.
- [Cancel recurring](https://www.smartretry.com/docs/api-reference/recurring/cancel.md): Cancel an active recurring billing series and stop all future scheduled payments.
- [Charge recurring](https://www.smartretry.com/docs/api-reference/recurring/charge.md): Manually trigger a charge against an active merchant-managed recurring series.
- [Initialize recurring](https://www.smartretry.com/docs/api-reference/recurring/init.md): Create a new recurring billing agreement and process the first payment in the series.
- [Recurring status](https://www.smartretry.com/docs/api-reference/recurring/status.md): Retrieve the current state of a recurring billing series, including schedule details, payment history, and upcoming transactions.
- [Update recurring](https://www.smartretry.com/docs/api-reference/recurring/update.md): Modify the schedule, amount, or end conditions of an existing recurring billing series.
- [Authentication](https://www.smartretry.com/docs/authentication.md): How to authenticate your SmartRetry API requests.
- [Changelog](https://www.smartretry.com/docs/changelog.md): API updates, new features, and breaking changes.
- [Decline Codes](https://www.smartretry.com/docs/concepts/decline-codes.md): Common decline reasons, what they mean, and how SmartRetry handles them.
- [How It Works](https://www.smartretry.com/docs/concepts/how-it-works.md): How SmartRetry analyzes and recovers declined payment transactions.
- [Recurring Payments](https://www.smartretry.com/docs/concepts/recurring-payments.md): How recurring and subscription payments work in SmartRetry.
- [Transaction Statuses](https://www.smartretry.com/docs/concepts/transaction-statuses.md): All possible transaction status values and what they mean.
- [Transaction Types](https://www.smartretry.com/docs/concepts/transaction-types.md): Understanding the payment transaction types supported by SmartRetry.
- [Introduction](https://www.smartretry.com/docs/index.md): Recover lost revenue from declined payments with intelligent retry and routing.
- [Payment Methods](https://www.smartretry.com/docs/integration/payment-methods.md): Supported payment methods and how to specify them in requests.
- [Postman collection](https://www.smartretry.com/docs/integration/postman.md): Import the SmartRetry API collection into Postman for quick testing and exploration.
- [REST API](https://www.smartretry.com/docs/integration/rest-api.md): How to integrate with the SmartRetry REST API.
- [Sandbox](https://www.smartretry.com/docs/integration/sandbox.md): Test your integration in the SmartRetry sandbox environment before going live.
- [SDKs and libraries](https://www.smartretry.com/docs/integration/sdks.md): Official and community libraries for integrating with SmartRetry.
- [Terminals](https://www.smartretry.com/docs/integration/terminals.md): Understanding terminals and how they scope your payment operations.
- [Webhooks](https://www.smartretry.com/docs/integration/webhooks.md): Receive real-time notifications when transaction events occur.
- [Quick Start](https://www.smartretry.com/docs/quickstart.md): Make your first payment request with SmartRetry in minutes.

## OpenAPI Specs

- [openapi](https://www.smartretry.com/docs/api-reference/openapi.json)