Twilio gives you VoIP numbers that fail verification on Cash App, Coinbase, Tinder, Stripe — and most modern fraud-detection stacks. We give you real AT&T, T-Mobile, MobileX prepaid lines — provisioned in seconds, via REST API, billed by usage.
Your AI agent can write code, browse the web, and book reservations. Then it hits a Cash App or Coinbase signup screen, gets a SMS code, and the verification rejects the number as VoIP. Game over. Here's why:
If your product gives an AI a phone, we're the layer that makes it actually work in the real world.
PollyReach, Vapi, Retell, Bland, ElevenLabs Conversational, OpenAI Realtime. Your agent calls a restaurant for a reservation — and the restaurant sees a real US phone number, not "Unknown VoIP." You bring your own voice stack; we provide the number and the caller-ID identity.
OpenAI Operator, Anthropic Computer Use, Browserbase, Skyvern. When a signup flow asks a user to confirm a phone number, the buy_sms_number and get_sms MCP tools return a real US number and the received code.
Personal AI that screens your calls, answers spam, schedules with humans. Customer gives the assistant a real MeiSIM number; assistant routes calls, transcribes voicemails, replies via SMS — all behind a number that's indistinguishable from a human's line.
A number your customers will trust — not a 5-digit shortcode or a VoIP line. Inbound SMS on a T-Mobile API line is delivered to your webhook, or polled over the API. Outbound texting is sent from the device the eSIM is installed on; there is no send-SMS API endpoint today.
Authenticated REST, prepaid balance, per-key rate limits. No SDK to install — plain HTTP calls. For SMS verification, use the MCP tools below.
MeiSIM runs a hosted Model Context Protocol server. Point any MCP-compatible client — Claude, Cursor, Windsurf, or your own agent — at one URL and it gets eSIM, US-number, and SMS-verification tools natively. No SDK, no polling loop, no glue code.
Tools your agent gets the moment it connects:
Listed in the public MCP registry as io.github.shauliko/meisimusa-mcp. Payment for agent-initiated purchases runs on your MeiSIM API key / wallet.
A monthly price per number; usage is billed separately. Two ways to receive: a T-Mobile API line reads its own SMS over the API with webhook push, and a carrier eSIM delivers its texts to the device you install it on.
Pre-built integrations and SDKs for the AI agent platforms we see most often.
Webhook template for voice AI inbound + outbound
Register the line's SIP credentials; the number rings your agent
Personal-AI phone number provisioning
Custom function tool for number lookup
SMS verification helper for headless browser agents
Python + JS tool definitions
No-code automation nodes
For Claude Desktop, Cursor, Zed
For pure voice agents that only call humans (booking, support), Twilio is fine. The problem is two-way SMS verification — Cash App, Coinbase, Tinder, Venmo, Stripe Atlas, banking apps, and most fraud-detection stacks block VoIP numbers entirely. If your AI agent needs to sign up for accounts, receive 2FA codes, or hold a phone identity that mimics a real user, VoIP fails. Our numbers don't.
From API call to active eSIM ready for use: typically 8–25 seconds for AT&T retail, 30–90 seconds for MobileX/T-Mobile depending on carrier load. We pool inventory in advance so you're not waiting for carrier-side provisioning on every request.
Yes. The Scale tier includes a bulk API endpoint that returns up to 1,000 numbers in a single async job. Useful if you're spinning up a verification farm or testing across many accounts.
Two products, and the difference is where the SIM physically is.
T-Mobile API line — a real T-Mobile number, and we receive its SMS. The SIM lives in a gateway rather than in a handset, so the message reaches us and we pass it on: webhook push to your URL (POST /api/v1/sms/webhook to set it, HMAC-signed as X-MeiSIM-Signature) with GET /api/v1/sms/messages as the record behind it. A real carrier number that your code can read is the combination most stacks cannot offer.
Carrier eSIM — you install it on a device, and its texts go to that handset. Not to us, and no provider can change that; it is how a SIM works. Right for a phone somebody uses, wrong for code that needs to read the message.
T-Mobile API line with voice: yes, both directions, over SIP. Each line gets its own SIP credentials (host, port, user, password); register them from any voice-AI platform, PBX or softphone, and the number rings your agent. Outbound shows the line's own number, a real mobile. Usage is billed separately from a prepaid balance, and each line carries one call at a time, so ten simultaneous calls means ten lines.
Carrier eSIM: calls ring the handset it is installed on, like any phone.
The rule that comes with it: a line used for robocalling, unsolicited calls or texts, or verification fraud is blocked the moment we see it and the account is closed for good, no warning, no refund. Legitimate agents never notice this rule exists.
Credit/debit (Stripe), PayPal, Apple Pay, Google Pay, USDT crypto (TRC20 + ERC20), Alipay, WeChat Pay. We deliberately accept crypto because a lot of our AI-agent customers are international startups that struggle with US payment rails.
Indie tier: best-effort. Growth: 99.5% number-active SLA + 4h support response. Scale: 99.9% SLA + 1h response + dedicated Slack channel.
Carriers occasionally deactivate prepaid lines for inactivity, suspected fraud, or quota issues. We monitor and replace automatically on Growth and Scale tiers — we notify you and issue the replacement. There is no automatic in-flight SMS forwarding — a code sent to the old number in that window is lost, so re-request it after the swap.
Prepaid, by card or USDT, from a single number up. We set up your API key, send the docs link, and you can be in production in 20 minutes.
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