Changelog
All notable changes to the HTTPayer API will be documented on this page.This changelog follows Semantic Versioning. API version
is independent of the documentation version.
[Unreleased]
In Development
- Upcoming features and improvements
[1.0.0] - 2026-01-06
Added
-
Core Endpoints: Initial release with payment-gated API functionality
POST /sim- Simulate payment requests without executionPOST /proxy- Execute x402 payment-gated API calls with creditsPOST /relay- Make privacy-preserving, cross-chain enabled API calls through a x402 clientGET /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
- EIP-3009 gasless USDC transfers using
-
Relay Features:
POST /relay/sim- Simulate relay paymentsGET /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 checkPOST /llm/translate- Translate text to SpanishPOST /llm/chat- General-purpose chat endpoint
-
System Endpoints:
GET /health- Service health checkGET /config- Server configuration
Security
- API key authentication via
x-api-keyheader for account-based endpoints - Payment signature validation using EIP-3009
- Rate limiting per wallet address
Migration Guides
This is the initial release. Future migration guides will be added here when
breaking changes are introduced.
Version History
| Version | Release Date | Status | Notes |
|---|---|---|---|
| 1.0.0 | 2026-01-05 | Current | Initial stable release |
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Documentation
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Changelog Format
We follow Keep a Changelog 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: 2026-01-06

