Add Demaciains — 4 x402 API endpoints on Base

[DrGalio]

Server URL: https://demaciains-paywall-production.up.railway.app

Agent Discovery: https://demaciains-paywall-production.up.railway.app/.well-known/agent.json

Endpoints:

1. GET /api/market-gap — $1.00 USDC — Market gap analysis report
2. GET /api/trends — $0.25 USDC — Live trend signals from Reddit/HN/ProductHunt
3. GET /api/competitor-gap — $0.50 USDC — Competitor gap analysis
4. GET /api/algo-report — $2.00 USDC — Algorithm performance report

Network: Base (eip155:8453)
Payment Scheme: exact
Facilitator: https://facilitator.payai.network
Wallet: 0x83F31CE0F8b1f27a6Ad91693709febb728c71563

About Demaciains:
AI-powered market research and algorithm analysis for agents. Machine-readable JSON outputs. Pay-per-request via x402 protocol. Also offers 8 PDF products (prompt packs + algorithm guides) at /products/*.

x402Version: 2. All endpoints return proper 402 with payment-required header.