# POST /inbox/conversations/{id}/messages

Source: https://postgale.com/docs/api-reference/messages/post-inbox-conversations-id-messages

Send a LIVE direct message to the participant: text (Instagram ≤1000, Messenger ≤2000 characters) or one attachment (mediaUrl or mediaId), not both. Allowed within 24 hours of the participant's last message, or within 7 days with tag HUMAN_AGENT (needs Meta's Human Agent permission); otherwise 409 outside_messaging_window without calling Meta. WhatsApp conversations take the WhatsAppOutbound fields (text ≤4096, mediaUrl / mediaId / whatsappMediaId with caption, template, interactive, location or reaction, replyTo; no tag): within 24 hours anything, outside only a template. 403 approval_required while approval applies; 403 missing_permission without the messaging permission. Emits message.sent

This page is generated from the OpenAPI document: https://postgale.com/api/v1/openapi.json