How Tendo works

Last updated: 25 April 2026

This is the technical-but-friendly version of what happens when a customer support email reaches Tendo. If you'd rather see the nuts-and-bolts of connecting your sending inbox, jump to{" "} Connecting your inbox.

The flow at a glance

  1. Inbound. Your customer emails your support address. You forward that mailbox to a per-store Tendo address (we generate it during setup). Postmark receives the email and posts it to Tendo as a webhook.
  2. Sanitize. Tendo strips quoted-reply blocks and signatures so the AI sees only what your customer actually wrote, not a re-quoted copy of every previous round-trip.
  3. Classify. Claude Haiku reads the cleaned ticket and tags an intent: refund_request, shipping_question, policy_inquiry, product_issue, escalate_to_human, or other.
  4. Retrieve. Tendo looks up your knowledge-base chunks via vector embeddings — return policy, shipping, FAQs. If the ticket mentions an order number (e.g.,{" "} #1004), Tendo fetches the order snapshot from Shopify webhooks (financial status, fulfillment, total) so the AI has real context.
  5. Generate + judge. Claude Sonnet drafts a reply, proposes a refund (with a specific dollar amount), or escalates. A second pass — the "judge" — re-reads the draft for accuracy, citation correctness, and policy alignment, then returns a confidence score.
  6. Guardrail. Hard rules check things the AI doesn't decide: maximum refund cap, daily refund cap, your first-N-actions-require-approval setting, escalation keywords (chargeback, lawyer, BBB), and whether the order even exists. Anything the guardrails reject becomes an escalation, not an autonomous action.
  7. Approve. The proposed action lands in your inbox. You see the draft, the confidence score, the cited knowledge chunks, and the order context. You approve, edit inline, or reject.
  8. Execute. Approved replies send through your connected Gmail / Microsoft 365 / SMTP account (your domain, your reputation). Approved refunds go through the Shopify Admin API directly.
  9. Thread. When the customer replies, the round trip closes back through Tendo's inbound address (set as Reply-To on the outbound) and threads to the same ticket. No new tickets for follow-ups.

What Tendo never does

What Tendo gets wrong

AI is wrong sometimes. Tendo's strategy is: when in doubt, escalate. Most failures we see are over-cautious, not over-confident — the AI escalates a ticket the merchant could have handled with a one-liner. We tune toward that side deliberately.

Edge cases worth knowing: tickets in languages other than English may classify with lower confidence; multi-topic emails ("two questions, one about returns and one about a missing package") almost always escalate; carrier-side damage may escalate when your KB doesn't explicitly cover it.

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