external_id is echoed for contacts linked to this integration.GET /contacts?email=maria@example.com or GET /contacts?phone=%2B5511987654321 (URL-encode the + as %2B) returns the matching contacts in data (empty when none). An invalid phone answers 422 invalid_phone.curl --location '/contacts?after=undefined&limit=undefined&query=undefined&email=maria%40example.com&phone=+5511987654321'{
"data": [
{
"uuid": "9c2e4f31-7a55-4d0b-8f6a-2c9d1e5b7a03",
"external_id": "customer-1847",
"phone": "+5511999998888",
"name": "Maria Silva",
"email": "maria@exemplo.com.br",
"tags": [
"cliente",
"vip"
],
"custom_fields": {
"tier": "gold",
"utm_source": "google",
"utm_campaign": "black-friday"
},
"tracking": {
"utm_source": "google",
"utm_campaign": "black-friday"
},
"last_interaction_at": "2026-08-25T14:31:09.412-03:00",
"created_at": "2026-07-02T09:12:44.001-03:00",
"updated_at": "2026-08-25T14:31:09.412-03:00"
}
],
"meta": {
"next_cursor": "MTQ3"
}
}