Skip to content

WA_NLT_REQUIRED_MISS

Category: whatsapp  ·  Severity: critical  ·  Channel: WhatsApp

A required NLT modifier on the WhatsApp template body resolved to a missing value for the sample contact. At send time, every contact whose properties match the sample would have the entire WhatsApp message suppressed — no message is sent.

What it means

NLT (the plain-English template language) lets you mark an expression as required. When a required expression can't be resolved for a contact — because the property is missing or empty — Synapse suppresses the whole message for that contact rather than sending an incomplete one.

WhatsApp Inspect renders your template's body_nlt against a sample contact. If a required expression misses, the render is suppressed and this critical finding fires — the only critical severity in the WhatsApp channel.

Warning

This mirrors the send-time posture: a suppressed WhatsApp message produces a durable failed row in the WhatsApp logs and no call to Twilio. The message is not delivered.

Why it matters

A required miss is a silent delivery failure. Contacts missing the property receive nothing, and the gap is invisible unless you check the WhatsApp logs. Catching it before you submit or send prevents a segment of your audience from silently dropping out.

How to fix it

  1. Backfill the missing property on the contacts this template targets, so the required expression always resolves.
  2. Remove the required modifier if the value is genuinely optional — the message will then send with a fallback (or empty) value instead of being suppressed.

Finding context

json
{
"reason": "required expression 'first_name' resolved to empty"
}