Model Selection
By default, NinjaCat Agents are driven by Claude Sonnet 4.5, Anthropic's best model for complex agents and coding. However, depending on your Agent’s specific needs—whether for faster response times or enhanced reasoning—you can choose an alternative model.
NinjaCat will adjust the default model when newer, better models come out after spending time testing that the output is as good or better than the prior default, and if it is more cost efficient. When the default is changed, it only impacts brand new Agents. Users will need to adjust the model for existing Agents if they would like to. NinjaCat will not adjust the model for existing agents to avoid disrupting an already perfectly crafted Agent (sometimes a model change could require tweaks to the prompt).
Agent Model Option Updates — Feb 17 & 18th, 2026
On Feb 17 & 18th, several older Anthropic and OpenAI models were removed from the Agent Builder as model options for Agents. All affected agents were automatically reassigned to newer alternatives — no action is required on the user's part.
Auto-reassignment logic:
- Agents driven by Claude Opus 4.5 → reassigned to Claude Opus 4.6
- Agents driven by any other removed Anthropic model → reassigned to Claude Sonnet 4.6 (newly released)
- Agents driven by a removed OpenAI model → reassigned to GPT-5.2 - Thinking
We recommend reviewing your agents' output after the update, as there may be minor differences in behavior that could benefit from prompt adjustments.
Models removed:
Anthropic: Claude Opus 4.5 (standard & Thinking), Claude Sonnet 4 (standard & Thinking), Claude 3.7 Sonnet (standard & Thinking), Claude Sonnet 4.5 (standard & Thinking)
OpenAI: GPT-5.1 series (Thinking, Instant), GPT-5, GPT-4.1 series (Standard, Mini, Nano), o3 series (Low, Med, High), o4-mini series (Low, Medium, High), o3-mini series (Low, Med, High), GPT-4o
Available Model Options in NinjaCat
Anthropic Models
| Model | Release Date | Context Window | Input $ / 1M | Output $ / 1M | Notes |
|---|---|---|---|---|---|
| Claude Opus 4.6 | Feb 2026 | ~200K | ~$5 | ~$25 | Strongest reasoning & coding; most expensive Anthropic option |
| Claude Opus 4.6 - Thinking | Feb 2026 | ~200K | ~$5 | ~$25 | Enhanced reasoning variant of Opus 4.6 |
| Claude Sonnet 4.6 (Default) | Feb 2026 | ~200K | ~$3 | ~$15 | New default for all newly created Agents. Best-balanced Claude model — strong performance at moderate cost |
| Claude Sonnet 4.6 - Thinking | Feb 2026 | ~200K | ~$3 | ~$15 | Enhanced reasoning variant of Sonnet 4.6 |
| Claude Haiku 4.5 | Oct 2025 | ~200K | ~$1 | ~$5 | Fastest & most affordable Claude option |
| Claude Haiku 4.5 - Thinking | Oct 2025 | ~200K | ~$1 | ~$5 | Enhanced reasoning variant of Haiku 4.5 |
OpenAI Models
| Model | Release Date | Context Window | Input $ / 1M | Output $ / 1M | Notes |
|---|---|---|---|---|---|
| GPT-5.2 - Thinking | Oct 2025 | ~400K | ~$1.75 | ~$14 | Latest flagship; strong reasoning + long context. Default reassignment for agents on removed OpenAI models |
| GPT-5.2 - Instant | Oct 2025 | ~400K | ~$1.75 | ~$14 | Faster, lower-latency variant of GPT-5.2 |
| GPT-5 Mini | Aug 2025 | ~400K | ~$0.25 | ~$2 | Cost-efficient; good for well-defined tasks at lower cost |
| GPT-5 Nano | Aug 2025 | ~400K | ~$0.05 | ~$0.40 | Cheapest & fastest GPT-5 variant; great for summarization and classification workloads |
Google Models
| Model | Release Date | Context Window | Input $ / 1M | Output $ / 1M | Notes |
|---|---|---|---|---|---|
| Gemini 3 Pro - Low | Nov 2025 | ~1M | ~$2.00 | ~$12.00 | Best-in-class reasoning & multimodal from Google; massive context window |
| Gemini 3 Pro - High | Nov 2025 | ~1M | ~$2.00 | ~$12.00 | Higher reasoning effort variant |
| Gemini 3 Flash - Low | Dec 2025 | ~1M | ~$0.50 | ~$3.00 | Fast, efficient; combines Gemini 3 Pro reasoning with Flash-level latency and cost |
| Gemini 3 Flash - High | Dec 2025 | ~1M | ~$0.50 | ~$3.00 | Higher reasoning effort Flash variant |
Note: In the Agent Builder, some models offer both a standard and a "Thinking" variant. The Thinking variant supports deeper reasoning but may come with higher cost and latency. For most agents, the standard variant is recommended unless your use case requires complex multi-step reasoning.
How to Choose the Right Model
AI models are continuously improving — what is "best" today may be surpassed in weeks or months. NinjaCat will continue evaluating and adding models that demonstrate better intelligence, efficiency, or performance.
General guidance:
- For most agents: Claude Sonnet 4.6 (default) is the best starting point — strong performance at reasonable cost.
- For complex reasoning or coding tasks: Claude Opus 4.6 or GPT-5.2 - Thinking.
- For speed or cost-sensitive tasks: Claude Haiku 4.5, GPT-5 Nano, or Gemini 3 Flash.
- For large context windows: OpenAI GPT-5.2 series (~400K) or Google Gemini 3 series (~1M).
For the latest information from each provider, see their documentation:
Anthropic Claude Models OpenAI GPT-5 Prompting Guide Google Gemini
Note: When switching between models, prompt adjustments may be required to maintain optimal Agent performance. We will provide further guidance on prompt modifications as we continue testing and learning.
Updated about 1 month ago