Outcome: each step in your sequence runs on the model you choose — a flagship model for the first touch into a key account, a fast model for follow-ups — with one place to set a default for the whole campaign.
Where to find it
Open a campaign → Touch Points → click a personalized step (email, LinkedIn, SMS or WhatsApp) → Prompt tab. The model picker is the dropdown in the toolbar under the prompt, next to the variable and asset counters. The same picker appears wherever a prompt lives: AI condition steps, AI enrichments, the call flow, the web assistant, agentic settings and the AI actions in Workflows.
Before you start
The standard models are available on every plan.
Premium models — including GPT-6 Astra, Claude Fable 5.1, Claude Opus 5.5 and Gemini 3.8 Flash — are a Professional and Enterprise feature. On other plans they stay visible in the list but cannot be selected; the tooltip explains the upgrade.
Steps: change the model for one step
On Touch Points, click the step and open the Prompt tab.
Click the model dropdown in the toolbar (it shows the current model, for example Alta).
Scroll the list: standard models first, then the premium models. Pick the one you want, for example GPT-6 Astra.
Click Save. Only this step changes; the rest of the sequence keeps its own models.
Steps: set a default for the whole campaign
Close the step panel and click the ⋮ Sequence options button at the top right of the sequence tree.
Choose Default AI model: …. The Default AI Model dialog opens.
Pick a model, for example Claude Opus 5.5.
Turn on Apply to existing steps if you also want the steps you already built to switch; leave it off to change only steps you add from now on.
Click Done, then Save the campaign.
Click the image to watch the clip (recorded in Alta).
What you should see
The toolbar dropdown shows the model you picked, and the Default AI model entry in Sequence options shows the campaign default. The step Preview tab regenerates drafts with the selected model, so you can compare two models side by side on the same prospect.
Good to know
Alta is the default model; switching to a premium model is a per-step choice unless you use the campaign default.
Reply assistants, call assistants and AI enrichments each have their own model picker in their builders.
In AI enrichments a premium model is billed as a premium AI enrichment, so it uses more credits per row than a standard model.
Ask Alta itself (the chat) does not have a model picker at the moment.