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// use case · approve-by-reply

Draft by agent. Launch by human.

Let an agent prepare a send — a campaign, an outreach, a customer reply — but hold it behind a human gate. Drin emails the draft to an approver; a one-word reply releases it. No dashboard to open, and the approval thread is the audit trail.

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Free sandbox to integrate · Production from $3/month

Blue duotone engraving: a robot clerk sliding a finished letter up to a drawbridge gate that stays raised; a human at a desk on the far side reads a copy and stamps 'APPROVE', and only then does the gate lower to let the sealed envelope-plane take off — a ledger beside the desk logging each stamp.
// the job

Autonomy where it's safe. A human where it counts.

Handing email to an agent is powerful and a little frightening: you want it to do the work, but not to press send on the wrong thing. The usual answer is a bespoke approval dashboard nobody checks.

Approve-by-reply uses the tool the approver already lives in — their inbox. The agent does everything up to the send; Drin routes the finished draft to a named approver, who releases it with a one-word reply from any mail client. Every approval is recorded in the thread, so who signed off on what is never in question.

Human-in-the-loopReply to releaseFull audit threadAgent-native
#01 — How it works

Attach an approver. Drin holds the send.

Add an approval block to any send and Drin queues it instead of dispatching, mails the draft to the approver, and releases it the moment they reply to approve — or drops it if they decline.

Read the docs →
send · gated on human approval
curl -X POST https://api.drin.run/v1/emails \
  -d '{
    "to":       "customer@acme.com",
    "subject":  "Your renewal quote",
    "approval": { "approver": "lead@yourco.com" }
  }'

# held · lead@yourco.com gets the draft · reply "approve" to release
#02 — What you get

The three that make it work.

DRIN · APPROVE-BY-REPLY — WHAT YOU GETSHEET OF 3
01.1A gate, not a brake

The agent researches, drafts and queues — everything up to the send. The human only decides go or no-go, so throughput stays high.

01.2Approve from your inbox

The approver replies from any mail client — no dashboard, no new app. The workflow lives where they already are.

01.3The thread is the record

Who approved, when, and on what draft — captured in the mail trail, so the audit answer is already written.

#03 — Built from

The surfaces that power it.

Not a bolt-on — this job runs on the same platform as everything else you send and receive. One account, one bill.

Receive →Agents overview →Pricing →
#04 — Questions

Asked about approve-by-reply.

Does the approver need a Drin login?+

No. They approve by replying to the draft email from their normal inbox. The gate works over plain email — the tool they already use all day.

What happens if nobody approves?+

The send stays queued and is never dispatched. You can set it to expire, and the pending state is visible over the API and dashboard.

Can I approve programmatically too?+

Yes. Approval can be released over the API as well as by reply, so a second system or a person can act as the gate.

Is this only for agents?+

No — it's useful any time a draft needs a second set of eyes, agent-authored or not: outbound sales, support replies, a first campaign.

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