# Payneteasy OpenAPI: Generate API Clients in Minutes

Source: https://payneteasy.com/blog/payneteasy-open-api

_The Payneteasy OpenAPI is a server-to-server Processing API: 29 POST endpoints for sale, payout, refund, recurring, 3-D Secure and card tokenisation, with an OpenAPI 3.1 contract._

26.06.2026

4 min read

Table of contents

1. [What the OpenAPI is](#what)
2. [What you can do with it](#capabilities)
3. [Built for AI-assisted integration](#format)
4. [Integrate fast with the specification](#integrate)

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Payneteasy OpenAPI specification makes connecting to our gateway simple and gives full control of the gateway's functionality through API rules and AI agents.

- **One machine-readable contract:** Payneteasy publishes its long-standing Processing API as an **OpenAPI 3.1** specification — one published file that code generators and AI tools can read automatically, alongside the existing [documentation](https://doc.payneteasy.com/integration/index.html).
- **Generated in minutes:** typed clients and request/response models can be generated in minutes, reducing the manual coding around the API contract.
- **Full transactional scope:** one consistent contract covers sale, pre-authorisation, capture, void, refund, [payout](/payment_technologies/payouts), transfer, recurring payments, card tokenisation, status and [3-D Secure](/solutions/3ds_adapter).
- **Your format, your tools:** requests default to form-urlencoded or switch to JSON with a single header; auto-generated SDKs (Java, Python, Go, TypeScript and other languages supported by OpenAPI Generator), one-click Postman/Insomnia import, and interactive docs come out of the box.
- **AI-ready:** hand the spec URL to an AI coding agent (e.g. Claude Code) and it writes a working client, tests, and examples right in your codebase.

## What the OpenAPI is

**OpenAPI** is an industry-standard way to describe an API in a single, structured file — every endpoint, every input, every data type. It's a blueprint that software can read and act on directly, not just a manual a person has to interpret.

### The integration bottleneck

[Payment service providers](/branches/provider), [banks](/branches/banks), [fintechs](/branches/fintech), merchants and their developers put real effort into integrating new merchants into their systems. Even with thorough documentation, a developer still has to work through field formats, enum values, and error semantics before the first request succeeds — manual work around the API contract that a machine-readable specification can reduce.

Payneteasy addresses that bottleneck with a complete OpenAPI specification for its long-standing Payneteasy Processing API. This specification makes a single machine-readable file authoritative. Payments and payouts are described in one specification that integrators can read, validate against, and generate code from on day one.

**From prose-only documentation to prose plus a machine-readable API contract.**

| Prose documentation | Plus a machine-readable contract |
|---|---|
| Detailed prose documentation, written for a person to read | A structured OpenAPI 3.1 specification covering the entire API |
| API responses in a single format (form-urlencoded) | Responses can also be returned as JSON, which is easier for many tools to deserialize and validate automatically |
| Detailed prose, without a machine-readable contract file | One published file that code generators and AI tools can all read automatically |
| Client code written by hand against the prose docs | Typed clients and models can be generated in minutes, reducing manual coding around the API contract |
| SDKs and Postman/Insomnia collections assembled manually | Auto-generated SDKs (Java, Python, Go, TypeScript and other languages supported by OpenAPI Generator) and one-click Postman/Insomnia import |
| Endpoints explored by reading the documentation | Interactive docs you can browse and send live test requests from — no setup |
| No machine-readable contract for SDK generators or AI tools | AI coding assistants (Claude Code, Cursor) read the spec and scaffold a working client |

## How It Works, In Practice

Three steps, with less manual coding around client setup and request/response models.

1. **Point at the link.** Any tool — Postman or an AI assistant — opens our OpenAPI spec URL.
2. **Tool reads the spec.** It parses every endpoint, field, and data type automatically.
3. **Working code appears.** A typed client, data models, and usage examples — ready to use.

## What you can do with it

It's a single, structured "blueprint" of our entire payment API — written in a format that both people and software can read automatically.

- **Generates client code and models from the OpenAPI contract.** It helps generate starter code and typed models in the programming language a partner's developers use.
- **Plugs into common dev tools.** It imports directly into tools developers already use daily, like Postman — no manual setup required.
- **Understood by AI assistants.** AI coding tools (Claude Code, ChatGPT, Cursor) can read it and build a working integration automatically.

## Built for AI-assisted integration

The same standards-based contract is what makes the API ready for AI-assisted integration. Because the specification is machine-readable, a developer can hand the spec URL to an AI coding agent such as Claude Code and ask it to integrate Payneteasy; the agent reads the contract and generates a working client — with models, tests, and examples — directly in the team's own codebase, in their stack and conventions, in minutes. For analysts scoring developer experience, that is a concrete, standards-driven capability rather than a proprietary add-on.

## Integrate fast with the specification

Because the contract is OpenAPI 3.1, let your tools do the typing: generate client SDKs in your language, import it into Postman or Insomnia, or feed it to an AI coding assistant to scaffold the API integration. For the full reference and step-by-step integration guides, see the [Payneteasy OpenAPI documentation](https://doc.payneteasy.com/integration/openapi.html).

## Related products

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- [Leads Protection System (Merchants)](/solutions/leads_protection_system) — The technological solution for GDPR compliance, and will protect your most valuable data and leads from hackers, thieves, malware, AND trusted employees. Based on the best PCI DSS practices.