XGuard — Verify the payment before it leaves

# XGuard > XGuard is a guarded x402 v2 verification and settlement gateway for autonomous agents and applications on Base mainnet USDC. XGuard charges $0.04 only for a accepted authenticated economic attempt. Verification, malformed requests, failed settlements, duplicates, replays, and discovery requests are not billable. ## Discovery - [Provider manifest](https://xguardgate.com/.well-known/x402/facilitator.json): machine-readable facilitator identity, integration, pricing, onboarding, and safety metadata - [Agent Card](https://xguardgate.com/.well-known/agent-card.json): machine-readable agent/service capability metadata - [MCP server metadata](https://xguardgate.com/.well-known/mcp/server.json): official remote MCP server metadata - [Remote MCP](https://xguardgate.com/mcp): streamable HTTP MCP endpoint for agent discovery - [Bazaar resources](https://xguardgate.com/discovery/resources): machine-readable catalog of x402-paid HTTP APIs and MCP tools - [Bazaar search](https://xguardgate.com/discovery/search?query=x402): searchable XGuard catalog surface - [OpenAPI](https://xguardgate.com/openapi.json): complete HTTP API description - [Supported x402 kinds](https://xguardgate.com/supported): live x402 capabilities and authoritative signer attribution - [Status](https://xguardgate.com/status): operational status - [Readiness](https://xguardgate.com/readyz): live mainnet route readiness ## Core API - POST https://xguardgate.com/v1/register — create a merchant identity and receive a Bearer API key - POST https://xguardgate.com/verify — verify an x402 v2 payment authorization - POST https://xguardgate.com/settle — settle an x402 v2 payment with duplicate protection and finality tracking ## Authentication Protected merchant and payment endpoints use Authorization: Bearer <merchant-api-key>. ## Protocol x402 version 2; Base mainnet (eip155:8453); exact scheme; native USDC. ## Agent discovery Pre-payment XGuard offer: https://xguardgate.com/v1/payment/offer (fre

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