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

# Changelog

> Track updates, new features, and changes to the HTTPayer API

# Changelog

All notable changes to the HTTPayer API will be documented on this page.

<Note>
  This changelog follows [Semantic Versioning](https://semver.org/). API version
  is independent of the documentation version.
</Note>

***

## \[1.1.0] - 2026-02-27

### Changed

* **Proxy 502 on upstream payment refusal** — When the target API returns 402 after all sync
  retries, the proxy now returns `502 Bad Gateway` instead of silently dropping the response.
  The response body includes an optional `webhook_id` when background blockchain polling is active
  — use `GET /webhooks/:id` to track whether the payment eventually confirms on-chain.

* **No more 202 responses** — Async status is tracked via the `webhook_id` field on 502 proxy
  responses. Webhook records still transition through `async_processing` → terminal state as
  before.

***

## \[1.0.0] - 2026-01-06

### Added

* **Core Endpoints**: Initial release with payment-gated API functionality

  * `POST /sim` - Simulate payment requests without execution
  * `POST /proxy` - Execute x402 payment-gated API calls with credits
  * `POST /relay` - Make privacy-preserving, cross-chain enabled API calls through a x402 client
  * `GET /balance` - Check account credits balance

* **Payment Features**:

  * EIP-3009 gasless USDC transfers using `transferWithAuthorization`
  * Multi-chain support: Base, Base Sepolia, SKALE Base, SKALE Base Sepolia, Solana, Solana Devnet
  * Payment verification and retry logic
  * Async refunds via webhooks

* **Relay Features**:

  * `POST /relay/sim` - Simulate relay payments
  * `GET /relay/limits/{address}` - Check wallet spending limits
  * Custom header forwarding to target APIs

* **Webhook System**:

  * `GET /webhooks/{id}` - Get async task status

* **LLM Integration**:

  * `GET /llm/health` - LLM service health check
  * `POST /llm/translate` - Translate text to Spanish
  * `POST /llm/chat` - General-purpose chat endpoint

* **System Endpoints**:
  * `GET /health` - Service health check
  * `GET /config` - Server configuration

### Security

* API key authentication via `x-api-key` header for account-based endpoints
* Payment signature validation using EIP-3009
* Rate limiting per wallet address

***

## Migration Guides

<Info>
  This is the initial release. Future migration guides will be added here when
  breaking changes are introduced.
</Info>

***

## Version History

| Version | Release Date | Status  | Notes                          |
| ------- | ------------ | ------- | ------------------------------ |
| 1.1.0   | 2026-02-27   | Current | 502 on payment refusal, no 202 |
| 1.0.0   | 2026-01-05   | Stable  | Initial stable release         |

***

## Subscribe to Updates

Stay informed about API changes:

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  <Card title="GitHub Releases" icon="github" href="https://github.com/httpayer">
    Watch our GitHub repository for new releases
  </Card>

  <Card title="Documentation" icon="book" href="/api/overview">
    Browse the complete API documentation
  </Card>
</CardGroup>

***

## Changelog Format

We follow [Keep a Changelog](https://keepachangelog.com/) conventions:

* **Added**: New features and endpoints
* **Changed**: Changes in existing functionality
* **Deprecated**: Soon-to-be removed features
* **Removed**: Removed features
* **Fixed**: Bug fixes
* **Security**: Security vulnerability fixes

***

**Last Updated:** 2026-02-27