How to Use Kimi K3 in Kimi Code
Kimi Code exposes K3 under the model ID `k3`. The safest workflow is to select it at the start of a new session, keep reasoning settings stable, and give the agent explicit repository instructions and boundaries.
Select K3 in a new session
In the official CLI, open the model selector with `/model` and choose K3. In the VS Code client, use the model dropdown in the input bar. Third-party clients should set the model ID to `k3` where the integration supports Kimi Code models.
/model
# Choose: Kimi K3 (model ID: k3)Do not switch mid-session
Switching models invalidates the context cache and can break the thinking-history continuity K3 expects. Official guidance recommends starting a new session for better output and lower consumption. The same principle applies when changing reasoning effort repeatedly.
Plans, context and 401 errors
Kimi Code documentation says access and maximum context depend on membership. Some plans expose K3 with a 256K limit, while higher plans unlock up to 1M. A 401 can therefore mean the requested model or context exceeds the current entitlement, not that the typed credential is wrong.
Give the agent durable instructions
K3 is optimized for long, difficult tasks and can be more proactive than expected. Put repository commands, test requirements, restricted files and approval boundaries in an `AGENTS.md` file or an equivalent system instruction so the model does not have to infer them repeatedly.
- Name the exact test and formatting commands.
- Define when the agent must ask before changing external state.
- Require a final diff review and real verification.
Frequently asked questions
What model ID does Kimi Code use for K3?
Use `k3`. The public Kimi API uses `kimi-k3`, which is a different client-facing identifier.
Why did usage rise after switching to K3?
The previously built context cache no longer matches, so the conversation must be prefetched again. Starting a new session is the recommended approach.
Primary sources
This guide prioritizes official Kimi and Moonshot AI materials. Product access and pricing can change, so confirm live details at the linked sources.