AI Builder

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What the AI Builder is

The AI Builder is the fastest way to go from “we should send a re-engagement series” to a draft that’s actually ready to ship. You describe what you want; Halo plans the whole sequence, drafts every email in parallel, sets the delays, and hands you back a fully populated series in the manual builder. It works for series specifically: multi-step email sequences. For one-shot emails, use the broadcast editor’s AI assistant on the right side of the page (or ask Ask AI). Find it inside any series at Automation > [your series] > AI Builder, or by selecting AI Agents as the build mode when you create a new series.

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When to use it

You can switch between the two at any time while the series is in draft. The AI Builder writes its output into the same step structure the manual builder uses, so once it’s drafted, you can drag steps around, add conditions, change senders, etc.

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The two phases

The builder runs in two phases, both of which you watch happen live in the chat panel.

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Phase 1: Plan

You start with a chat. The planner asks a few targeted questions to nail down:

• Series goal: welcome, re-engagement, onboarding, trial conversion, churn save, etc.
• Audience: who should receive it (the planner can read your existing audience filters or suggest new ones)
• Length: how many emails (3 is a typical starter; the planner will recommend a count based on your goal)
• Cadence: how spread out they should be (most welcome series sit at 0, 1, 3, 7 days)
• Tone: friendly, formal, technical, founder-style, etc.
• Sender: which teammate the emails come from
• Reply-to: where replies should land

When the planner has enough, it produces a plan card with one row per email: order, subject (proposed), theme, brief, and delay. You can edit anything: subject, delay, order, and you can add or remove emails. Nothing has been written yet, this is just the outline. The plan also has a series summary (“a 4-step welcome series for newly-signed-up Pro users that walks through setup, integrations, and a soft upgrade prompt”), a positioning flag (product vs marketing), a tone descriptor, and a target audience description. These are stored on the series and used to keep all the email drafts on-brand.

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Phase 2: Build

Once you click Build, Halo spawns one sub-agent per group of emails and writes them in parallel:

• Each sub-agent has the plan, the series summary, your knowledge base (so emails can reference real product features, names, and value props), and your brand voice (extracted from your help articles, About content, and any custom system prompts).
• Sub-agents render their thinking and progress live, you’ll see “Agent 1: drafting emails 1 to 3” with a status indicator.
• Each completed email appears as a card with the subject and a 1-line preview. Click to expand the full HTML body.

Build typically takes 30 to 90 seconds for a 3 to 6 email series. Longer series (10+ emails) take a couple of minutes because the sub-agents work in parallel but the writing itself takes time. When all sub-agents finish, you get a fully populated series in the manual builder canvas. From there:

• Edit any email in the regular email editor
• Add waits, conditions, or in-app steps
• Switch a step from Branded to Personal styling
• Add A/B variants
• Change the trigger (manual / event / segment match / user created)
• Activate when you’re ready

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What the AI Builder uses to ground the writing

The output is only as good as the context. The builder pulls from: If your knowledge is thin (no help center yet, no crawled docs), the drafts will be generic. The cure is uploading some product docs first. Even a single Markdown file of “what our product does and our top 5 value props” makes the difference between a generic email and one that sounds like you wrote it.

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Editing the plan vs. editing the drafts

There are two places to make changes, and the right one depends on how big the change is: If you’ve heavily edited the drafts and then want to add another email, use Add step in the manual builder rather than re-running the AI Builder, otherwise you’ll lose your edits.

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Limitations and trade-offs

A few things the AI Builder explicitly does not do:

• It only drafts. It never activates. Every series the builder produces lands in status='draft' and stays there until a human flips it on.
• It only writes email steps. No SMS, no in-app, no waits, no conditions. You add those manually after the build.
• It picks one trigger. The default is manual. You can change it to user_created, event, or segment_match after the build, but the builder doesn’t currently optimize content for trigger type.
• It doesn’t pick the audience for you. It writes for the audience you (or your filters) describe in the chat, but the actual filter set lives on the series and is independent. Always sanity-check the audience count before activating.
• It can be off-brand. If your knowledge base is thin or your tone descriptor is vague (“friendly”), drafts default to a SaaS-house style. Provide a stronger tone description and meaningful knowledge.

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Permissions

Same permissions as series in general: The model itself runs on your workspace’s AI plan; usage shows up under regular AI usage tracking.

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Workflow tips

• Start with Halo’s templates if you’re stuck. “Welcome series”, “Re-engagement”, and “Feature announcement” are good prompts for the planner.
• Be specific about who, not what. “A 4-email welcome series for newly-signed-up Pro users in B2B SaaS” is way better than “A welcome series.”
• Ground in URLs. If you have a great help article that explains a feature, paste the URL into the chat. The planner will reference it.
• Read the first draft, then edit hard. Treat AI Builder output like a junior copywriter’s first pass. The structure is usually right; the words always need a second look.
• Use Halo’s Personal email style for the first email. It looks like a real human reaching out, and that’s the email people are most likely to reply to.

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Where to go next