Cat Jam is now available in stealth for free on AI Gateway
By Steven Van ·
Free during the stealth period, the text-only reasoning model works with the AI SDK, OpenAI and Anthropic-style APIs, and coding agents.
Cat Jam, a reasoning model for coding and agentic tasks, is now on Vercel AI Gateway as a stealth model, and it is free to use during the stealth period. The model page lists a 1M-token context window, 131K max output, and a release date of 15 October 2026.
What the model supports
- Function calling, so agents can connect it to your own tools.
- Structured outputs that follow a JSON schema you supply.
- Reasoning text returned alongside the answer.
- Text input only.
- Reasoning efforts of low, medium, high, xhigh and max.
Data retention
Zero Data Retention (ZDR) is not available for this model. Prompts may be retained for safety reasons. The model page adds that prompts and responses may be used for training and model improvement.
Using it
The model name is stealth/cat-jam. It works with the AI SDK, the OpenAI-compatible Chat Completions and Responses APIs, and the Anthropic-compatible Messages API. For the AI SDK, set it as the model in generateText or streamText.
To use it in Claude Code, Codex, Cursor and other coding agents, install the latest Vercel CLI, run npx vercel ai-gateway setup, then select stealth/cat-jam in the agent. A model playground is also available for trying it out.
AI Gateway reflects provider pricing with no markup and charges no platform fee on inference, including on Bring Your Own Key requests.