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

# API Reference

> The Anton Payments merchant API. Versioned, idempotent, cursor-paginated.

The Anton API is a REST API over HTTPS. All requests and responses are JSON. All dates are ISO 8601 UTC. All monetary amounts are **decimal strings** — never floats — to avoid rounding errors.

## Base URLs

| Environment | Base URL                        |
| ----------- | ------------------------------- |
| Production  | `https://api.antonpayments.com` |
| Sandbox     | `https://api.antonpayments.dev` |

## Authentication

Every request requires an OAuth 2.0 access token (DPoP-bound) AND a per-request DPoP proof. Static API keys are not accepted on v1. See [Authentication](/authentication) for the full flow, including a copy-paste curl quickstart.

```http theme={}
Authorization: DPoP <access_token>
DPoP: <proof JWT, fresh per request>
```

## Conventions

* **Versioning.** All endpoints live under `/v1/`. Breaking changes ship as a new version; `/v1/` remains available for the life of the contract.
* **JSON.** Request bodies are `application/json`. Field names are `snake_case`. Unknown fields in requests are rejected with `422`.
* **Amounts.** Monetary values are strings: `"1234.56"`, not `1234.56`. Parse them as decimals, not floats.
* **Timestamps.** RFC 3339 / ISO 8601 in UTC: `"2026-04-15T13:45:02Z"`.
* **Identifiers.** Prefixed opaque strings: `pay_...`, `ben_...`, `mer_...`, `ins_...`, `bat_...`, `wbh_...`. Treat them as opaque — do not parse or compare substrings.
* **Errors.** Every error response follows a consistent envelope with a machine-readable `code` and a human-readable `message`. See [Errors](/api-reference/errors).

## Cross-cutting topics

<CardGroup cols={2}>
  <Card title="Idempotency" icon="rotate" href="/api-reference/idempotency">
    Safely retry any mutation with `Idempotency-Key`.
  </Card>

  <Card title="Pagination" icon="list" href="/api-reference/pagination">
    Cursor-based pagination on every list endpoint.
  </Card>

  <Card title="Rate limits" icon="gauge-high" href="/api-reference/rate-limits">
    Per-merchant and per-endpoint request ceilings.
  </Card>

  <Card title="Errors" icon="triangle-exclamation" href="/api-reference/errors">
    Error envelope, status codes, and remediation.
  </Card>

  <Card title="Webhook events" icon="bolt" href="/api-reference/webhook-events">
    Every event type and its payload schema.
  </Card>

  <Card title="Webhook signing" icon="signature" href="/api-reference/webhook-signing">
    Verify signatures on every incoming delivery.
  </Card>
</CardGroup>