Available models
Posit Assistant lets you choose which large language model handles your request. Each model offers a different balance of capability, speed, and credit usage, and you select the active model in the Posit Assistant interface.
Different models consume your Posit AI usage credits at different rates. The rates below are expressed relative to Claude Sonnet 4.6, which serves as the baseline. For example, a request that would use 1% of your credits on Sonnet 4.6 would use roughly 0.33% on Haiku 4.5 and roughly 1.67% on Opus 4.6.
The Relative Usage Amount column shows the inverse: how much usage you get for the same credit spend. For example, Gemma 4 gives you roughly 10x as much usage as Sonnet 4.6 for the same credits.
| Model | Provider | Relative Credit Cost | Relative Usage Amount |
|---|---|---|---|
| Gemma 4 | Google (open weights) | 0.1x | 10x |
| Claude Haiku 4.5 | Anthropic | 0.33x | 3x |
| Claude Sonnet 4.6 | Anthropic | 1x (baseline) | 1x (baseline) |
| Claude Opus 4.6 | Anthropic | 1.67x | 0.6x |
Gemma 4
Gemma 4 is an open-weights model from Google, available in Posit AI at one-tenth the credit usage of Sonnet 4.6 and roughly one-third the credit usage of Haiku 4.5. It is the lowest-consumption option in Posit AI.
Gemma 4 works well for:
- Basic data analysis
- Importing, tidying, and visualizing data
- Information retrieval and short factual questions
It is less reliable than the Claude models on longer, multi-step tasks. You might see a strong response on one turn and a misread on the next. We do not recommend Gemma 4 for long-running agentic coding or complex package development. When you use it, plan to steer it actively and review its code and output closely.
Gemma 4 is served via GPU infrastructure that does not retain data. Any retention by Posit is governed by your data preferences.
Claude models
Posit AI sends Claude requests to Anthropic under a Zero Data Retention agreement.
Claude Haiku 4.5
A fast, lightweight model. Good for quick questions, simple edits, short refactors, and follow-ups that do not need deep reasoning. The Claude option that draws credits the slowest.
Claude Sonnet 4.6
The recommended default for most data science work: writing and editing R code, exploratory data analysis, building Quarto reports, and typical agentic coding tasks. Balances capability and credit usage.
Claude Opus 4.6
The most capable Claude model. Use it for complex architectural decisions, large refactors, hard debugging, and problems where Sonnet has already struggled. It draws credits the fastest; reserve it for tasks that justify the higher consumption.
Choosing a model
A practical pattern:
- Start with Sonnet 4.6 if you are not sure.
- Drop to Haiku 4.5 or Gemma 4 for shorter, simpler tasks to stretch your credits further.
- Step up to Opus 4.6 when you hit a problem that needs more reasoning, or where a smaller model has already failed.
For more on how model selection affects your monthly credits, see the FAQ on credit consumption.
Models behind Next Edit Suggestions
Next Edit Suggestions (NES) runs on specialized models hosted by Posit, not on the models above. NES usage is unlimited, is not metered against your credit balance, and is not configurable from Posit Assistant.