Check Numbers
curl --request POST \
--url https://api.linkupapi.com/v2/messages \
--header 'Content-Type: application/json' \
--header 'x-api-key: <x-api-key>' \
--data '
{
"account_id": "<string>",
"action": "<string>",
"params": {
"phone_numbers": [
"<string>"
]
}
}
'import requests
url = "https://api.linkupapi.com/v2/messages"
payload = {
"account_id": "<string>",
"action": "<string>",
"params": { "phone_numbers": ["<string>"] }
}
headers = {
"x-api-key": "<x-api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {'x-api-key': '<x-api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({
account_id: '<string>',
action: '<string>',
params: {phone_numbers: ['<string>']}
})
};
fetch('https://api.linkupapi.com/v2/messages', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.linkupapi.com/v2/messages",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'account_id' => '<string>',
'action' => '<string>',
'params' => [
'phone_numbers' => [
'<string>'
]
]
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"x-api-key: <x-api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.linkupapi.com/v2/messages"
payload := strings.NewReader("{\n \"account_id\": \"<string>\",\n \"action\": \"<string>\",\n \"params\": {\n \"phone_numbers\": [\n \"<string>\"\n ]\n }\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("x-api-key", "<x-api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.linkupapi.com/v2/messages")
.header("x-api-key", "<x-api-key>")
.header("Content-Type", "application/json")
.body("{\n \"account_id\": \"<string>\",\n \"action\": \"<string>\",\n \"params\": {\n \"phone_numbers\": [\n \"<string>\"\n ]\n }\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.linkupapi.com/v2/messages")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<x-api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"account_id\": \"<string>\",\n \"action\": \"<string>\",\n \"params\": {\n \"phone_numbers\": [\n \"<string>\"\n ]\n }\n}"
response = http.request(request)
puts response.read_body{
"success": true,
"data": {
"results": [
{ "phone_number": "+33612345678", "on_whatsapp": true, "conversation_id": "[email protected]" },
{ "phone_number": "+33600000000", "on_whatsapp": false, "conversation_id": null }
],
"total_results": 2
},
"metadata": { "action": "check_numbers", "account_id": "your-whatsapp-account-id", "credits_consumed": 1, "timestamp": "2026-09-26T15:40:00Z" }
}
{
"success": false,
"error": { "code": "INVALID_PARAMS", "message": "At most 50 phone numbers per call" },
"metadata": { "action": "check_numbers", "account_id": "your-whatsapp-account-id", "credits_consumed": 0, "timestamp": "2026-09-26T15:40:00Z" }
}
Messaging
Check Numbers
Check which phone numbers are on WhatsApp.
POST
/
v2
/
messages
Check Numbers
curl --request POST \
--url https://api.linkupapi.com/v2/messages \
--header 'Content-Type: application/json' \
--header 'x-api-key: <x-api-key>' \
--data '
{
"account_id": "<string>",
"action": "<string>",
"params": {
"phone_numbers": [
"<string>"
]
}
}
'import requests
url = "https://api.linkupapi.com/v2/messages"
payload = {
"account_id": "<string>",
"action": "<string>",
"params": { "phone_numbers": ["<string>"] }
}
headers = {
"x-api-key": "<x-api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {'x-api-key': '<x-api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({
account_id: '<string>',
action: '<string>',
params: {phone_numbers: ['<string>']}
})
};
fetch('https://api.linkupapi.com/v2/messages', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.linkupapi.com/v2/messages",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'account_id' => '<string>',
'action' => '<string>',
'params' => [
'phone_numbers' => [
'<string>'
]
]
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"x-api-key: <x-api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.linkupapi.com/v2/messages"
payload := strings.NewReader("{\n \"account_id\": \"<string>\",\n \"action\": \"<string>\",\n \"params\": {\n \"phone_numbers\": [\n \"<string>\"\n ]\n }\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("x-api-key", "<x-api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.linkupapi.com/v2/messages")
.header("x-api-key", "<x-api-key>")
.header("Content-Type", "application/json")
.body("{\n \"account_id\": \"<string>\",\n \"action\": \"<string>\",\n \"params\": {\n \"phone_numbers\": [\n \"<string>\"\n ]\n }\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.linkupapi.com/v2/messages")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<x-api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"account_id\": \"<string>\",\n \"action\": \"<string>\",\n \"params\": {\n \"phone_numbers\": [\n \"<string>\"\n ]\n }\n}"
response = http.request(request)
puts response.read_body{
"success": true,
"data": {
"results": [
{ "phone_number": "+33612345678", "on_whatsapp": true, "conversation_id": "[email protected]" },
{ "phone_number": "+33600000000", "on_whatsapp": false, "conversation_id": null }
],
"total_results": 2
},
"metadata": { "action": "check_numbers", "account_id": "your-whatsapp-account-id", "credits_consumed": 1, "timestamp": "2026-09-26T15:40:00Z" }
}
{
"success": false,
"error": { "code": "INVALID_PARAMS", "message": "At most 50 phone numbers per call" },
"metadata": { "action": "check_numbers", "account_id": "your-whatsapp-account-id", "credits_consumed": 0, "timestamp": "2026-09-26T15:40:00Z" }
}
Overview
Tells which phone numbers have WhatsApp, from a connected WhatsApp account. Nothing is sent to them.This endpoint consumes 1 credit per call (up to 50 numbers). Ignore this if you’re on per-seat pricing: usage is unlimited.
Request
string
required
Your API key for authentication.
string
required
A connected WhatsApp account.
string
required
Must be
"check_numbers".object
required
Show params properties
Show params properties
string[]
required
Up to 50 numbers in international format, e.g.
+33612345678.Request
{ "account_id": "your-whatsapp-account-id", "action": "check_numbers", "params": { "phone_numbers": ["+33612345678", "+33600000000"] } }
{
"success": true,
"data": {
"results": [
{ "phone_number": "+33612345678", "on_whatsapp": true, "conversation_id": "[email protected]" },
{ "phone_number": "+33600000000", "on_whatsapp": false, "conversation_id": null }
],
"total_results": 2
},
"metadata": { "action": "check_numbers", "account_id": "your-whatsapp-account-id", "credits_consumed": 1, "timestamp": "2026-09-26T15:40:00Z" }
}
{
"success": false,
"error": { "code": "INVALID_PARAMS", "message": "At most 50 phone numbers per call" },
"metadata": { "action": "check_numbers", "account_id": "your-whatsapp-account-id", "credits_consumed": 0, "timestamp": "2026-09-26T15:40:00Z" }
}
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