Contacts
Look up contact
Look up contact information by phone number
GET
Description
This endpoint allows you to look up contact information by phone number. It returns contact data, whether they have replied to messages, and the WhatsApp session window status. It’s useful for conditional sending and automated follow-up workflows: before sending a follow-up, you can check if the contact has already replied and if the session window is active.The endpoint returns
200 even if the contact doesn’t exist. Use the found field to verify existence.Authentication header
Your Mindo API Key. Format:
mindo_xxxxxxxxxxxxxxxxxxxxxxxxQuery parameters
Phone number to look up. The system automatically normalizes the number, so it accepts multiple formats (E.164 with or without
+, with 15 for Argentina, with spaces or dashes).Response (200 OK)
true if the contact exists in any company list.Contact information.
null if not found.true if the contact has sent at least one message in any chat. Useful for follow-up logic: if false, the contact is a candidate for re-sending.Date/time of the last message sent by the contact.
null if they never replied.true if there’s an active WhatsApp session window (24h since the user’s last message). If active, free-text messages can be sent; if not, only approved templates.Expiration date/time of the active session window.
null if there’s no active window.Accepted phone formats
The system automatically normalizes the number. All these formats are equivalent:| Format | Example |
|---|---|
E.164 with + | +5492235961983 |
E.164 without + | 5492235961983 |
With 15 (Argentina) | +54223155961983 |
With 15 without + | 54223155961983 |
| With spaces/dashes | +54 223 15-596-1983 |
For numbers outside Argentina, use E.164 format with country code.
Use case: Conditional follow-up
Automated follow-up workflow
Automated follow-up workflow
Typical workflow for follow-up campaigns:
- Send initial template via
/api/v1/meta-templates/send/ - Wait a period (e.g.: 24-48 hours)
- Check status via
/api/v1/contact-lookup/?phone=... - Decide action based on the response:
found: false— Contact doesn’t exist, check the numberhasReplied: true— Already replied, don’t send follow-uphasReplied: false+sessionWindowActive: true— Send free-text follow-up messagehasReplied: false+sessionWindowActive: false— Send follow-up template
Python
JavaScript

