---
id: TASK-9
title: Implement x402 Micropayment Gateway for Community APIs
status: To Do
assignee: []
created_date: '2026-04-03 21:41'
labels:
  - typescript
  - x402
  - micropayments
dependencies:
  - TASK-7
documentation:
  - backlog/docs/402_CRDT_CrossChain_Fiat_Research.md
priority: medium
---

## Description

<!-- SECTION:DESCRIPTION:BEGIN -->
Enable HTTP 402-based pay-per-use access to community services using x402 protocol.

What x402 enables:
- Any community API endpoint gated by on-chain micropayment
- Client signs EIP-3009 transferWithAuthorization (gasless for USDC/EURC)
- Or Permit2 for any ERC-20 (including community tokens)
- Facilitator settles on-chain, server delivers resource

Implementation:
1. Express/Hono middleware using @x402/express or @x402/hono
2. Custom facilitator that routes fees to community treasury
3. Support both USDC and community token payments
4. Rate tiers: free tier → USDC micropayment → community token discount

Use cases for community token economies:
- API metering (data endpoints, AI inference, analytics)
- Content paywalls (@x402/paywall)
- Agent-to-agent commerce (AI agents pay with community tokens)
- Revenue routing to bonding curve reserve

Key contracts:
- x402 proxy: 0x402085c248EeA27D92E8b30b2C58ed07f9E20001 (all chains)
- USDC on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

SDK: @x402/core, @x402/evm, @x402/express, @x402/next, @x402/fetch, @x402/paywall
<!-- SECTION:DESCRIPTION:END -->

## Acceptance Criteria
<!-- AC:BEGIN -->
- [ ] #1 Express middleware gates API endpoints with 402 challenge
- [ ] #2 USDC payments settle correctly on Base
- [ ] #3 Community token payments work via Permit2
- [ ] #4 Revenue routes to community treasury contract
- [ ] #5 Free tier → paid tier escalation works
<!-- AC:END -->