Create a trigger

How triggers work#

When you create a trigger, Hermes generates a detection query from your description and runs it against your connected data source to find matching users. The query must return at minimum a user ID and an email address.

SELECT id, email
FROM users
WHERE created_at < now() - interval '14 days'
AND id NOT IN (
  SELECT user_id FROM team_members
);

Matching the query is not the same as getting an email. Each matched user goes through three stages:

1. Evaluate. An AI evaluator decides, per person, whether now is the right moment — it sees what they've already received from this trigger, whether they replied, their engagement, and their unsubscribe status. It can decide to send now, wait and re-check later, or skip the person entirely.
2. Draft. For everyone the evaluator green-lights, Hermes reads that user's actual data and writes a one-of-a-kind email — guided by your trigger prompt and by the evaluator's reasoning about why this moment matters.
3. Send or review. Drafts either go to your review queue or send automatically, depending on the trigger's send mode.

This evaluation step is why "50 users matched but only 12 emails drafted" is normal — the rest were skipped or deferred on purpose, and every decision is logged.

The email prompt#

The second half of a trigger is the prompt: a plain-language brief for what the email should accomplish. You're briefing a writer, not filling in a mail-merge — describe the intent, tone, and what to reference, and Hermes writes fresh copy per person.

Congratulate them on their first completed project. Reference what they
built specifically. Ask one short question about what they're planning
next. Keep it under 100 words, casual, no exclamation marks.

Types of triggers#

Transactional#

Triggered by a specific user action or event. Hermes evaluates each user individually and decides whether to send — so you are not just blasting everyone who matches a condition.

Examples:

• User signs up → send a personalized welcome email referencing what they came to do
• User has been inactive for 7 days → send a re-engagement email based on their last action
• User hits a usage limit → send an upgrade email that explains exactly what they would unlock

Marketing#

Ongoing campaigns that run continuously on a schedule. Hermes identifies matching users, drafts personalized emails from their data, and handles the compliance details — unsubscribe links, suppression, one-click opt-out — automatically.

Examples:

• End of month round-up — summarize each user's activity over the past 30 days
• Power users who haven't referred anyone — send a personalized referral ask
• Users approaching their renewal date — highlight what they have used and what they would lose

Schedule and re-contact rules#

You can also run any trigger immediately with Run now — from the dashboard, CLI (hermes triggers run), MCP, or API — and preview a trigger to see who the query matches before anything is drafted.

Auto-send vs. review mode#

Every trigger has a send mode. We recommend starting in review mode for any new campaign — it lets you inspect each drafted email before it goes out.

Sender and template#

Each trigger picks which sender identity the email goes out as, and how the copy is presented — plain text, simple HTML, or a branded designed template. Both default to your organization's settings if you don't override them.

Managing your triggers#

Triggers run indefinitely until you stop them. From the triggers dashboard you can pause, resume, or delete any trigger at any time, and see every run: when it scanned, how many people it detected, and any errors. Each trigger has a performance view showing delivery rates, open rates, and reply rates — so you can see what is working and adjust accordingly.