About NumRadar
NumRadar is an MCP server for agents that need to check whether phone numbers are registered on WhatsApp. It supports individual and bulk validation, with tools for job status and account credit balance.
Key features
- 01Check WhatsApp registration and number details
- 02Validate up to 10,000 numbers in bulk
- 03Track bulk job progress and results
- 04List recent jobs and check credit balance
Use cases
- 01Validate a contact list before a campaign
- 02Check a number before contacting it on WhatsApp
- 03Monitor a bulk validation job
- 04Estimate whether the account has enough credits
MCP support
NumRadar exposes phone-number validation tools and prompts to MCP clients. Clients can connect to its hosted endpoint with a bearer token; a CLI package is also available for clients that require a spawned command.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://numradar.app/mcpclaude mcp add --transport http app-numradar https://numradar.app/mcp{"mcpServers":{"app-numradar":{"type":"http","url":"https://numradar.app/mcp"}}}Open in Cursor{"servers":{"app-numradar":{"type":"http","url":"https://numradar.app/mcp"}}}Open in VS Code{"mcpServers":{"app-numradar":{"type":"http","url":"https://numradar.app/mcp"}}}{"mcpServers":{"app-numradar":{"serverUrl":"https://numradar.app/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
https://numradar.app/mcpAuth requiredTools
Details
From the project README@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_KEY
Create 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/mcp
Point 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
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.