Smart Replies

Smart Replies generates contextual, AI-powered responses to form submissions using a knowledge base you provide. Useful for contact forms, support inquiries, FAQ forms, or any scenario where you want an immediate reply.

How it works

1. A submission arrives and passes validation and spam checks
2. Postbox reads the submission data and the linked knowledge base
3. An AI-generated reply is created based on the submission content and knowledge base
4. The reply is either stored for your review or sent directly, depending on the mode

Requirements

• Knowledge base linked to the form (see Knowledge Bases section)
• Smart replies enabled on the form (smart_reply_enabled: true)
• Available AI credits

Modes

Draft mode (default)

The reply is generated and stored on the submission. Visible in the dashboard, via API, and in webhooks - but not sent anywhere. You review it and decide what to do.

Set with smart_replies_mode: "draft".

Auto mode

Postbox looks for an email field in the submission data:

• Email found - The reply is sent directly to that email address from {form_name} <hey@usepostbox.com> with subject "Re: Your submission to {form_name}"
• No email found - The reply is stored with status "completed" (same behavior as draft mode)

Webhooks and connectors fire regardless of whether the reply is sent.

Set with smart_replies_mode: "auto".

Setting up smart replies

1. Create a knowledge base with relevant content (FAQs, docs, policies)
2. Create or update a form with:
   • smart_reply_enabled: true
   • knowledge_base_id: "{uuid}"
   • smart_replies_mode: "draft" or "auto"
3. Submissions to that form will now generate replies automatically

Reply data in submissions

When you retrieve a submission, reply data appears in these fields:

Field	Description
reply_status	"pending" (not yet generated), "completed" (generated, ready for review), "sent" (auto-sent via email), "failed" (email delivery failed)
reply_content	The generated reply text, or null
reply_reason	Context when reply is not sent (e.g., "no email field found in submission"), or null
replied_at	Timestamp of when the reply was sent. Only set when reply_status is "sent".

Cost

Each smart reply costs $0.01 in AI credits. On the free plan, this comes from your 50 lifetime credits. On Pro, from your 500 monthly credits (with metered overflow).

Disabling smart replies

Toggle per-form in the form settings or via the API. When disabled, no replies are generated for new submissions.