NumRadar
Check whether phone numbers are registered on WhatsApp, from your AI agent.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
claude mcp add --transport http numradar 'https://numradar.app/mcp' --header 'Authorization: <Your numradar API key as a Bearer token: Bearer nr_live_... Create one at https://numradar.app/app/keys>'{
"mcpServers": {
"numradar": {
"type": "http",
"url": "https://numradar.app/mcp",
"headers": {
"Authorization": "<Your numradar API key as a Bearer token: Bearer nr_live_... Create one at https://numradar.app/app/keys>"
}
}
}
}@numradar/mcpclaude mcp add numradar -e 'NUMRADAR_KEY=<your numradar_key>' -- npx -y @numradar/mcp@0.2.2{
"mcpServers": {
"numradar": {
"command": "npx",
"args": [
"-y",
"@numradar/mcp@0.2.2"
],
"env": {
"NUMRADAR_KEY": "<your numradar_key>"
}
}
}
}Environment variables
NUMRADAR_KEYrequired secret numradar API key (nr_live_...). Create one at https://numradar.app/app/keys
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
Contents
@numradar/mcp
Check whether phone numbers are registered on WhatsApp, from your AI agent.
numradar answers one question well: is this number on WhatsApp? This is its Model Context Protocol server, so an agent can ask that question directly — validating a list, auditing contacts before a campaign, or checking a balance before spending it.
npx @numradar/mcp --token nr_live_YOUR_KEYCreate a key at numradar.app/app/keys.
Most people should not install anything
numradar runs a hosted MCP server. No package, no local process, no version to go stale on anyone's laptop:
https://numradar.app/mcpPoint your client at that URL with an Authorization: Bearer nr_live_... header and you are done.
{
"mcpServers": {
"numradar": {
"type": "http",
"url": "https://numradar.app/mcp",
"headers": {
"Authorization": "Bearer nr_live_xxx"
}
}
}
}The npm package exists for one real case: clients whose config file accepts a command to
spawn but not a URL. claude_desktop_config.json is the common one. If you are editing a file
like that, you need the package:
{
"mcpServers": {
"numradar": {
"command": "npx",
"args": ["-y", "@numradar/mcp", "--token", "nr_live_xxx"]
}
}
}Configuration for 15 verified clients — Claude Code, Cursor, Windsurf, Zed, VS Code, Cline and the rest — is at numradar.app/mcp-server.
Tools
| Tool | What it does | Cost |
|---|---|---|
validate_number | One number. Registered or not, business account, line type, country. | 1 credit |
bulk_validate | Up to 10,000 numbers. Returns a job id immediately. | 1 per definitive result |
get_job_status | Progress counters, optionally per-number results. | Free |
list_jobs | Recent bulk jobs on the account. | Free |
get_balance | Credits remaining. | Free |
Prompts
Clients that support MCP prompts surface these as slash commands.
| Prompt | Arguments | What it does |
|---|---|---|
/check_numbers | numbers | Validate a list and summarise which are reachable on WhatsApp. |
/clean_contact_list | numbers, purpose | Audit a list before a campaign, and report what to fix. |
/check_before_spending | count | Estimate the cost of a run and check the balance covers it. |
Billing, and why it should change how an agent uses this
One credit per definitive answer — registered or not registered. Beyond that:
- Invalid and unparseable numbers cost nothing. Send them. An agent that pre-filters numbers it is unsure about drops real contacts to save credits it was never going to spend.
- An inconclusive upstream result costs nothing.
- Credits never expire.
Numbers should be E.164 (+14155550100). Past a handful, prefer bulk_validate over a loop of
validate_number: it is one job to poll rather than N round trips.
Options
--token <key> | Your API key. Also read from NUMRADAR_API_KEY; the flag wins if both are set. |
--base <url> | API origin. Defaults to https://numradar.app. |
--version | Print the version and exit. |
--help | Print usage and exit. |
Security
The API key is a bearer credential for your account. --token puts it in your shell history and in
whatever config file spawns the process — prefer NUMRADAR_API_KEY from a secret store where your
client supports it. Keys are revocable from
the dashboard; revoke immediately if one is exposed.
Every tool call is authenticated, rate-limited and billed through numradar's ordinary public REST
API. The MCP server does not embed the checker and has no separate billing path, so an agent
calling a tool is treated exactly like a backend calling curl.
About this repository
This is the home of the npm package — its issue tracker and documentation. The server's source lives in a private monorepo and is not published here.
Found a bug, or a client whose configuration does not work? Open an issue.
- API documentation
- MCP reference and per-client configuration
- Agent skills and the Claude Code plugin
Licence
MIT
Frequently asked questions
What is NumRadar?
Check whether phone numbers are registered on WhatsApp, from your AI agent.
How do I install NumRadar?
It runs as a remote server. In Claude Code: claude mcp add --transport http numradar 'https://numradar.app/mcp' --header 'Authorization: <Your numradar API key as a Bearer token: Bearer nr_live_... Create one at https://numradar.app/app/keys>'. For other clients, paste the JSON configuration from this page into their MCP settings.
Does NumRadar need an API key?
Yes. It expects NUMRADAR_KEY, Authorization, which you set in its configuration.
Is NumRadar open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains NumRadar?
It is published by numradar. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.