X402 Sms
Let your coding agent send US transactional SMS from chat without signing up for a monthly Twilio-style plan—pay $0.03 USDC per message via x402.
Overview
io.github.UltraStarz/x402-sms is a Grow-phase MCP server that sends one US transactional SMS per agent call for $0.03 USDC via x402 wallet payment.
What is this MCP server?
- MCP stdio server (npm x402-sms-mcp) exposing pay-per-call SMS to US numbers
- Fixed $0.03 USDC per outbound message settled through x402 micropayments
- Buyer wallet pays per invocation via required BUYER_PRIVATE_KEY env
- Agent-callable alternative to standing up full SMS provider billing for one-off sends
- $0.03 USDC per SMS send
- US phone numbers only
- stdio npm package identifier x402-sms-mcp v0.1.0
What problem does it solve?
You need the agent to text a US user once but do not want another monthly SMS vendor contract or dashboard hop for a single alert.
Who is it for?
Indie SaaS builders experimenting with agent-driven OTPs or alerts who already hold USDC and accept US-only, pay-per-message pricing.
Skip if: Teams needing bulk marketing SMS, non-US numbers, or regulated messaging without handling wallet keys and x402 payment setup themselves.
What do I get? / Deliverables
After you add the stdio server and fund BUYER_PRIVATE_KEY, the agent can trigger a priced SMS send with per-message USDC cost instead of provisioning a full provider stack.
- One outbound transactional SMS to a US phone number per paid MCP invocation
- Per-call USDC settlement through the x402 payment path
Recommended MCP Servers
Journey fit
Transactional SMS usually shows up after you have users: alerts, OTPs, and lifecycle nudges sit in Grow rather than initial Build. Lifecycle covers automated user-facing messages triggered by product events, which is what this pay-per-send tool targets.
How it compares
Pay-per-call SMS MCP integration, not a full communications suite or copywriting skill.
Common Questions / FAQ
Who is io.github.UltraStarz/x402-sms for?
Solo builders and agent users who want transactional US SMS from the IDE with micropayment billing instead of a traditional SMS API subscription.
When should I use io.github.UltraStarz/x402-sms?
Use it when an agent workflow needs a one-off or occasional US text—verification, alert, or lifecycle ping—and $0.03 USDC per send fits your budget model.
How do I add io.github.UltraStarz/x402-sms to my agent?
Install the npm package x402-sms-mcp, configure stdio MCP in your client, and set the secret BUYER_PRIVATE_KEY to the Ethereum wallet that pays each x402 call.