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Astell's AI models (Standard & Advanced)

Astell's Standard and Advanced chat models, what each is for, how they're priced, and when to use which.

What chat models does Astell offer?

Astell's chat models come in two tiers, Standard and Advanced, so you can match the model to the task:

• Standard (Fast): the everyday model. Ideal for quick questions, summaries, drafting, brainstorming, code explanations, meeting notes, and general lookups. Lowest per-turn cost.
• Advanced (Exacto): a higher-precision model for work that has to be exactly right: complex analysis, multi-step reasoning, and high-stakes writing.

Both are Astell's own models, post-trained and orchestrated for how work happens in Astell: following loops, citing sources, calling tools, and remembering context. They are tuned for this product and improve continuously, which is why they carry Astell names. Both draw from your monthly token pool. Grove workspaces can additionally enable frontier models, the leading labs' flagships offered as the labs ship them, at per-model rates.

How is chat billed?

Chat isn't billed by a separate message quota. Usage is token-based across both models and draws from your monthly token pool, the same pool that covers ingestion. Each turn costs tokens based on what you send and what the model returns, and the rate depends on the model: Fast costs less per turn; Exacto costs more on output.

When should I use Exacto?

Exacto is the Advanced model, built for more complex tasks. Reach for it when the Standard model isn't enough:

• Complex analysis and research
• Detailed technical documentation
• High-stakes business decisions
• Advanced code generation
• In-depth strategic planning
• Nuanced writing and editing
• Multi-step reasoning tasks

It consumes more tokens per turn than the Standard model on longer answers, so use it when the task genuinely needs the extra capability.

Which plans include which models?

• Sapling (free): Standard (Fast) only
• Tree: Standard (Fast) plus the Advanced model (Exacto)
• Grove: Standard (Fast), the Advanced model (Exacto), and optional frontier models
• Forest (Enterprise): everything in Grove, with custom terms as needed

How is chat usage metered?

Every model draws from your organization's monthly token pool, the same pool that covers Processed Data ingestion, Astell Actions, and Audits. (That allocation is 2,500 tokens on Sapling, 10,000/seat on Tree, 50,000/seat on Grove, and custom on Forest.) Each turn is billed on what you send plus what the model returns, at the model's rate. Exact per-message cost varies with length and complexity. Ultra mode counts more heavily against your pool; see Memory and Ultra Mode.

How many tokens does each model use?

Chat is billed on the tokens you send (input) plus the tokens the model returns (output), drawn from your monthly pool. Tokens consumed per 1,000 model tokens:

Fast is the cheaper model on both input and output; Exacto costs more, and the gap grows with longer responses since output carries the higher rate. Use Fast for everyday work and step up to Exacto when the task needs the extra precision or depth. Frontier models carry their own per-model rates.

Do context, memory, or long conversations cost extra?

Context and memory features do not carry their own separate fee. Paid plans give you more than the free tier: more context for a single response, and more session memory carried across threads and grouped threads. All chat draws tokens from your pool based on input and output, at the model's rate (see How chat token usage is measured). Tokens are also consumed for Processed Data ingestion; see Native vs. Processed Data.

How do file attachments affect token usage in chat?

If a file attached in chat needs Processed Data handling (for example OCR, transcription, or media parsing), the related ingestion cost applies in addition to normal chat usage. See What costs tokens in Astell?.

Which model should I start with?

Start with Fast (the Standard model). It handles most everyday work and costs the least per turn. Step up to Exacto when the answer has to be precise or the task needs the deepest reasoning.

Can I switch models mid-conversation?

You can switch between Fast, Exacto, and any frontier models your workspace offers at any time, including in the middle of a conversation.

How do I conserve token usage in chat?

Start with Fast and step up to Exacto only when you actually need the precision or depth; most waste comes from unnecessary back-and-forth on the Advanced model. Batch your questions into one request, be specific up front so you don't burn turns on follow-ups, and use a single "do-it-all" prompt instead of several separate ones. Example: instead of three separate Exacto prompts, ask one: "Analyze this document: summarize the content, identify key risks, and list action items with priorities."

What happens when I run out of tokens?

Viewing never breaks; acting needs tokens. When you hit your monthly limit:

• Native Data syncing and Search keep working normally, they never consume tokens.
• The Loops dashboard, loop detail, citations, unified search, and calendar view stay accessible. They read from the existing graph and don't require new token spend.
• Chat (every model) pauses until your tokens reset, you increase your token limit (allowing pay-as-you-go), or you upgrade your plan.
• Processed Data ingestion pauses. Anything already ingested stays searchable; only new ingestion is affected.
• Astell Actions pause. The Agent or chat can still propose what it would do, but the action isn't pushed until you have budget.

Notifications fire at 75%, 90%, and 100% of your limit.