Previewing and regenerating messages
Check what an agent will send before it sends it: generate a live preview of a lead's messages in Vetta, review each step, and regenerate after changing a skill file or prompt.
Updated October 25, 2026 · 6 min read
A live preview writes every AI message in the sequence for a lead, exactly as it would go out, without sending anything. Use it before you switch a sequence on, and again every time you change a prompt or a skill file.
A preview is not a throwaway sample. The drafts it writes are kept, and they are the messages the lead will receive when the sequence reaches them, unless you edit or regenerate them first. That is also why previewing costs nothing extra: the lead is not charged a second time at send.
Generate a live preview
- Open the agent's Leads tab and tick one or more leads.
- Click Preview in the bar at the bottom.
- Generate a live preview? shows how many leads and messages will be written, and the estimated credits. It writes every AI message in the sequence for the selected leads and runs any enrichment they still need. Nothing is sent: the drafts are yours to review.
- Click Yes, generate. Vetta shows its progress ("Working on 1 lead"), then opens the preview.
Agents · PreviewA lead you added yourself goes through the sequence's ICP check first. If they do not pass, the preview says "This lead did not qualify, so no messages were drafted." and gives you the answer before you go live: either the lead does not fit, or the ICP score is set too high.
Review the drafts
The preview has three columns:
- Previewing: the leads in this preview, and the credits used.
- The drafts: every message step for the selected lead, with its subject and body, in order. "Drafts only, nothing has been sent."
- Sequence: the agent's sequence, step by step, including conditions and their paths. Click a step to preview just that message; Show all steps goes back to all of them.
Each draft has an Edit button if you want to change one message for this lead by hand. Save keeps your wording, the step is marked Edited, and that is the version that will be sent. You can edit any step that has not been sent yet; a message that has already gone out cannot change. Looks good closes the preview.
Regenerate after a change
When a draft is not right, change what the AI follows, not the draft:
- Edit the skill file (Tuning AI messages with skill files) or the variable's prompt (Setting up AI variables).
- Back in the agent's Leads tab, tick the same lead and click Preview.
- The lead already has messages, so Show messages opens them without writing or charging anything.
- Click Regenerate. Vetta rebuilds every draft with the updated skill file and prompt, which uses credits again.
- Read the new drafts against the old ones. Repeat until they read right, then preview two or three other leads to make sure the change works beyond one person.
A changed prompt or skill file does not rewrite messages that are already written. Leads you previewed before the change will get the old drafts unless you regenerate them. Leads whose messages have not been written yet get the new version automatically.
Previewing a standalone sequence
A sequence you build yourself has the same check on its canvas. Click Preview: the canvas turns read-only, and every step shows its message with the variables still as placeholders. On the right are the leads waiting to be published.
- Click a lead. Vetta writes their AI message and fills in every variable, so each step reads exactly as they will receive it. Writing it uses credits, and you see how many.
- If a lead is missing a detail the message needs, such as their company name, they are flagged with Add Missing Details, and the step tells you which field is empty, so you can fix the record before you publish.
- If a message does not sound right, tick the lead and click Regenerate. You see the estimated credits first, then a fresh message is written.
Reading the messages before anything goes out, from both screens. In the agent UI, built for anyone starting, tick a lead on the Leads tab, click Preview, confirm the estimated credits and read the drafts beside the agent's sequence; Edit, Save and Regenerate fix a message. On the sequence canvas, the node UI for people proficient in Vetta, Preview makes the canvas read-only, a click on a lead fills every variable, and leads missing a detail are flagged with Add Missing Details. Both end in the same preview.
Transcript
Alex has a Lead Scout agent with a fresh batch of leads, and before anything goes out he wants to read the messages. The agent view is the simplest way to start. On the Leads tab he ticks Sofia, then clicks Preview in the bar at the bottom. Vetta opens Generate a live preview?, with the estimated credits, and nothing is sent. He clicks Yes, generate, and the preview opens. Sofia is on the left, the drafts are in the middle, and the agent's sequence is on the right, where a click on a step shows just that message. These drafts are what Sofia will receive, unless he edits or regenerates them first. Edit changes one message, Save keeps his wording, and Regenerate rewrites them after a skill file change. The sequence canvas is the backbone of every sequence, and it gives you full control of every node. Click Preview, and the canvas turns read-only, with every step showing its message and the variables still as placeholders. Click a lead on the right, and Vetta writes their AI message and fills in every variable, so each step reads exactly as they'll receive it. Writing it uses credits, and you'll see how many. If a lead is missing a detail, like a company name, they're flagged with Add Missing Details, and the step names the empty field, so you can fix the record before you publish. If a message doesn't sound right, tick the lead and click Regenerate, and you'll see the credits first. So whichever way you start, you finish in the same preview, reading every message before it goes out. Ahead of each batch, Mark asks Claude to preview five messages. Claude spends about 2 credits and flags 2 as generic. Claude, ChatGPT or any assistant you connect to Vetta works on your real workspace, so repeat this at every launch, then give it a bigger job. In Vetta, open Preview and edit the two yourself.
Common questions
Does previewing cost credits?
Writing the drafts uses credits, and the estimate is shown before you confirm. The drafts are kept and sent as they are, so the lead is not charged a second time at send, and opening messages a lead already has with Show messages costs nothing. See Generate a live preview.
Are the preview drafts what the lead will actually receive?
Yes, unless you edit or regenerate them first. A preview is not a throwaway sample. See Review the drafts.
Can I change one message for one lead by hand?
Yes. Click Edit on the draft and Save: the step is marked Edited and your wording is what gets sent. You can edit any step that has not been sent yet. See Review the drafts.
Why does the preview say "This lead did not qualify"?
A lead you added yourself did not pass the sequence's ICP check, so no messages were drafted. Either the lead does not fit, or the ICP score is set too high. See Generate a live preview.
I changed the prompt. Why does the preview still show the old text?
A changed prompt or skill file does not rewrite messages that are already written. Open the lead's messages and click Regenerate. See Regenerate after a change.
Does Regenerate use credits?
Yes. It rebuilds every draft for the lead with the updated skill file and prompt, which uses credits again. See Regenerate after a change.
Can I preview a sequence I built myself, not an agent?
Yes. Click Preview on the sequence canvas, then click a lead on the right to write their messages and fill in every variable. See Previewing a standalone sequence.
What does "Add Missing Details" mean on a lead?
The lead is missing a field the message needs, such as their company name. The step tells you which field is empty, so you can fix the record before you publish. See Previewing a standalone sequence.
Key outcome
Previewing turns AI messages from a leap of faith into something you sign off. A few minutes of preview and regenerate after each change is what keeps an agent's outreach on-voice as it scales.
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