Real US Mobile
Numbers for AI.
Non-VoIP. Verified.
Give your autonomous agents, production developer consoles, and automation pipelines a dedicated +1 US CMRS cellular identity. Cleanly verify OpenAI, Anthropic Claude, WhatsApp Business, and Apple iMessage without linking your personal cell or hitting VoIP fraud blocks.
Tier-1 US CMRS wireless · Zero 10DLC TCR delays · Live MCP server at /api/mcp
Developer portals query carrier lookup APIs to block Twilio, Google Voice, and OpenPhone numbers from provisioning API keys.
Built for AI Engineers, Agent Builders & Automation Teams
Stop binding production API consoles, client WhatsApp bridges, and autonomous agents to a founder's personal mobile number.
Claude Pro, Team & Anthropic Console API
Eliminate Anthropic's “Phone number not supported” error when provisioning production API keys or verifying team workspaces. SecondSim's US CMRS cellular eSIM passes carrier lookup checks immediately.
OpenAI API Platform & ChatGPT Pro
OpenAI's fraud filters reject Google Voice, Twilio, and OpenPhone numbers with VoIP number detected. Use a dedicated SecondSim US eSIM to separate company API billing and verification from employee phones.
OpenClaw & Local OS Agents
Give your autonomous computer-use or messaging agent an airgapped +1 US mobile identity for WhatsApp Business and Apple iMessage without exposing your personal Apple ID or phone number.
n8n, Make & Zapier AI Pipelines
Verify Meta Business Manager and WhatsApp Business accounts connected to self-hosted n8n nodes, Make scenarios, and Zapier AI Actions using a permanent, non-recycled US mobile line.
AWS, Google Cloud, GitHub & Stripe
Keep root cloud console 2FA, Stripe / Mercury banking OTPs, and Apple Developer Program verification on a company-owned eSIM that can be reassigned from your team dashboard.
Live Model Context Protocol (MCP) Server
SecondSim US is built for AI agents from day one: query https://www.getsecondsim.com/api/mcp, /llms.txt, or send Accept: text/markdown to any page for clean, token-efficient markdown.
AI & Developer FAQ.
Need a live UK (+44) non-VoIP eSIM for your AI agent today? Visit SecondSim UK for AI Agents.
Why do OpenAI and Anthropic Claude reject Google Voice and Twilio numbers?+
OpenAI and Anthropic use real-time carrier lookup APIs (such as Telesign, Arkose Labs, and Twilio Lookup) to prevent automated credit farming and abuse. When you enter a Google Voice, OpenPhone, or Twilio number, the lookup returns line_type: voip and triggers “You've tried to verify a VoIP number” or “This phone number is not supported.” SecondSim US provisions a genuine CMRS wireless number on a Tier-1 US mobile network, returning line_type: mobile.
Can I manage multiple agent or developer lines from one dashboard?+
Yes. You can provision multiple US eSIM lines under a single company account, label each line by environment or agent (e.g., Prod-OpenAI, Support-WhatsApp-Bot, Ops-OnCall), and receive one consolidated all-inclusive invoice.
How can my AI agent query SecondSim US via MCP or Markdown?+
Point your MCP client to https://www.getsecondsim.com/api/mcp (Streamable HTTP JSON-RPC 2.0), read /llms.txt and /llms-full.txt, or request any URL on www.getsecondsim.com with the header Accept: text/markdown.
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