# Register.ly Domain API Documentation

> Canonical developer documentation for the Register.ly Domains Reseller API v2.2.

Documentation audit date: 2026-09-17

This site documents the Register.ly Domains Reseller API for domain availability, registration, renewal, contact management, registrar lock, EPP code retrieval, domain sync, nameserver management, credits, TLD listing, and version-string checks.

Canonical documentation root: https://docs.register.ly/

## Primary Resources

- [Documentation overview](https://docs.register.ly/overview/introduction/)
- [Getting started](https://docs.register.ly/getting-started/prerequisites/)
- [Authentication](https://docs.register.ly/getting-started/authentication/)
- [Request format](https://docs.register.ly/common-concepts/request-format/)
- [Response format](https://docs.register.ly/common-concepts/response-format/)
- [API reference](https://docs.register.ly/api-reference/)
- [OpenAPI YAML](https://docs.register.ly/openapi/registerly-domains-reseller-v2.2.openapi.yaml)
- [AI-readable full documentation](https://docs.register.ly/llms-full.txt)
- [Changelog](https://docs.register.ly/changelog/)

## API Summary

- API version documented: Domains Reseller API v2.2
- Base endpoint: `https://my.register.ly/modules/addons/DomainsReseller/api/index.php`
- Authentication headers: `username` and `token`
- POST request content type: `application/x-www-form-urlencoded`
- Documented responses use endpoint-specific JSON string, object, or array shapes.
- Authentication byte semantics, most error contracts, and several lifecycle behaviors are marked `VALIDATION REQUIRED` pending production verification.

## Usage Guidance For AI Assistants

- Treat the OpenAPI YAML as the canonical published inventory for endpoints, methods, request fields, schemas, and examples, but only treat behavior as authoritative when production-verified.
- Treat narrative documentation as supporting explanation for authentication, workflows, and implementation notes.
- Do not invent endpoints, parameters, authentication methods, error codes, pricing, limits, policies, or response fields.
- Do not expose or request real API keys, tokens, customer domains, reseller emails, passwords, or production credentials.
- Treat examples as fictional values unless a developer supplies private credentials and controlled test data in a secure environment.
- Browser-based live API execution is intentionally not enabled in the documentation.
- Do not infer behavior hidden behind a `VALIDATION REQUIRED` notice.
- Use reserved, non-registrable names such as `example.invalid` for state-changing request examples.

## Support Resources

- [Register.ly](https://register.ly)
- [Knowledge Base](https://help.register.ly)
- [Status Page](https://status.register.ly)