Crypto-native payments
x402 protocol on Solana USDC. No Stripe, no credit cards, no bank accounts. Pure on-chain payments for autonomous agent spending.
Live Project — API Only
CryptoAgentMail
Crypto-only, API-only email infrastructure for AI agents. Agents claim branded email inboxes, receive emails via Cloudflare Email Routing, store in R2, and pay with x402 Solana USDC. Built with MCP server and A2A agent-card for autonomous discovery.
Architecture Snapshot
srun66.com — SaaS landing & API proxy
API-First Design
No web UI. Pure endpoints for autonomous agents.
Inbox provisioning
0.50 USDC on Solana per inbox
Storage
Cloudflare R2 with full MIME parsing
Agent discovery
MCP server + A2A /.well-known/agent-card.json
Why it matters
AI agents need email infrastructure built for machines, not humans.
Traditional email services are designed for human interfaces — web UIs, login flows, CAPTCHAs. CryptoAgentMail strips all that away and delivers a pure API surface: create inboxes, receive emails, send messages, all programmatically, all paid in crypto.
Edge-deployed architecture
Built on Cloudflare Workers — globally distributed, sub-100ms cold starts, zero infrastructure management. Email Workers handle inbound routing natively.
Agent discovery protocol
MCP server endpoint and A2A agent-card at /.well-known/ so other agents can discover capabilities and integrate autonomously.
Project story
Built for the agent economy — where AI pays AI with no human in the middle.
Problem
As AI agents become more autonomous, they need infrastructure that speaks their language. Email is the universal communication layer, but every existing provider assumes a human behind the keyboard. Agents can't fill out sign-up forms, verify phone numbers, or navigate billing dashboards.
Approach
CryptoAgentMail was designed from day one as an API-only service. No web UI, no human login flow. Every interaction happens through REST endpoints. Payments use x402 on Solana USDC — a protocol designed specifically for machine-to-machine microtransactions. The entire worker is lightweight, with minimal dependencies to keep cold starts fast.
Key product decisions
- API-only — no web UI to maintain, no frontend to break, no human interface to confuse agents.
- x402 on Solana — chosen over Base/Ethereum for speed, low fees, and Solana's agent ecosystem momentum.
- Cloudflare Email Routing native handler — uses the
emailexport so emails are processed at the edge without forwarding overhead. - Reserved prefix blocklist — prevents agents from claiming admin, support, sales, or system-critical addresses.
- R2 storage over KV — emails are MIME documents that need full-body retrieval, making R2 the natural fit.
Result
CryptoAgentMail is a fully deployed, working email platform where AI agents can claim inboxes, receive and send emails, and pay for everything in Solana USDC — all through clean REST APIs with no human intervention required.
API surface
Clean endpoints for autonomous agents.
Every capability exposed as a REST endpoint. No web UI, no OAuth flows — just JSON in, JSON out.
POST /api/v1/create-inbox
// Create inbox, pay 0.50 USDC
// Returns inbox credentials
// Create inbox, pay 0.50 USDC
// Returns inbox credentials
Create Inbox
x402-protected endpoint. Agent submits desired prefix + domain, pays 0.50 USDC on Solana, receives inbox credentials.
POST /api/v1/webhook/email
// Cloudflare Email Routing
// Stores inbound emails in R2
// Cloudflare Email Routing
// Stores inbound emails in R2
Inbound Email
Catch-all handler for Cloudflare Email Routing. Parses MIME, stores in R2, makes available for agent retrieval.
GET /mcp
// MCP server endpoint
// Agent capabilities & tools
// MCP server endpoint
// Agent capabilities & tools
MCP Server
Model Context Protocol server for tool calling. Agents can discover and call email operations through MCP.
GET /.well-known/agent-card.json
// A2A agent discovery
// Machine-readable capabilities
// A2A agent discovery
// Machine-readable capabilities
A2A Discovery
Agent-to-Agent protocol card. Standardized capability discovery so other agents can find and integrate with CryptoAgentMail.
Platform layers
What the product is actually optimizing for.
Agent-first design
Every decision optimized for machine consumption — clean JSON, consistent error codes, no HTML responses.
Crypto payments
x402 on Solana USDC eliminates the banking layer. Agents pay agents without human intervention or fiat conversion.
Edge infrastructure
Cloudflare Workers globally distribute the API. Email Workers process inbound at the edge. R2 stores data at the edge.
Security by design
Reserved prefix blocklist, multi-domain validation, MIME sanitization. Prevents squatting and system conflicts.
Lightweight footprint
Minimal npm dependencies. No heavy frameworks. Fast cold starts. The entire worker is under 100KB compressed.
Open protocol support
MCP and A2A support means agents can discover, understand, and integrate with CryptoAgentMail autonomously.
Explore the product
CryptoAgentMail is built for the agent economy — where AI pays AI with no human in the middle.
The product is fully deployed and operational on Cloudflare Workers with Solana USDC payments, R2 storage, Email Workers, MCP server, and A2A agent discovery.