Models

"Settings → Models" is split into two tabs: "Model sources" and "Default models". Model sources is where you connect and manage each source's accounts, endpoints, and model catalogs, along with the image, video, and speech endpoint settings; Default models is where you set the global choices for image, video, and speech generation, the advisor model, and the high, medium, and low effort levels. Browsing the settings page does not switch the main model a chat is currently using.

Klaus does not sell models and no membership is required: every source uses your own account or key, and Klaus neither meters usage nor charges licensing fees. Existing sessions that used official membership show the model as unavailable after the upgrade; simply pick another source to continue.

Model sources

There are two kinds of model sources: your own subscriptions, and custom API keys. Each subscription connects differently:

Source	How to connect
Claude Code	Browser sign-in, or reuse this machine's Claude sign-in; several accounts can be saved, see below
Codex	Browser authorization (device code), or reuse this machine's Codex sign-in
Qoder, QwenWork, QoderWork	Browser authorization, or reuse credentials from the official client already signed in on this machine
WorkBuddy	Pick the account edition (domestic or international) first, then sign in via browser authorization or reuse the matching sign-in already on this machine; both paths follow the selected edition
Kimi	Browser authorization, or enter an API key from the console
Bailian Token Plan	Enter the plan key and pick the China or international site; you can also sign in to the Bailian console to show Token Plan quota
MiniMax M Plan	Enter the plan key; the site can be auto-detected, China, or global
Zhipu Coding Plan	Enter the plan key and pick the matching site: China (bigmodel.cn) or international (z.ai); keys do not work across sites
Ark Coding Plan	Enter the plan key; you can also sign in to the Ark console to show Coding Plan quota

Traffic and quota on these sources belong to the corresponding provider account. MiniMax M Plan shares one subscription quota across text, image, speech, and video.

Custom API keys connect your own model service. Providers include Anthropic, OpenAI Compatible, Kimi API, DeepSeek, Google Gemini, AWS Bedrock, and Google Vertex; fill in the API key, endpoint, and model name. A few options that are easy to miss:

• OpenAI Compatible can use the Chat Completions or Responses protocol.
• Anthropic lets you choose which request header carries the key: x-api-key or Authorization: Bearer. Gateways that only accept Bearer work with the latter.
• You can declare which reasoning levels the model supports, whether it supports deep thinking, and whether it can read images. For a Qwen-compatible model declared with deep thinking, the chat's thinking switch directly controls whether each answer uses deep thinking.

Multiple Claude accounts and quota rotation

The Claude Code source can hold several accounts. After you are signed in, the "Sign in to Claude" and "Use local Claude login" buttons remain available for adding more accounts; signing in to the same account again only refreshes its credentials.

When the current account is rate-limited or out of quota, Klaus moves it to the back of the queue and retries the same request with the next account, without you switching anything; it only reports an error after every account has been tried. Authentication errors such as an expired sign-in do not trigger rotation; you are asked to sign in again. The sidebar's usage entry lists each account's remaining quota and marks the one in use.

Model effort levels

The high, medium, and low effort levels configure which model serves tasks of different complexity, and each level can use a model from a different source. For example, the high level can use a Claude subscription, the medium level a custom Qwen, and the low level a small custom model — they do not have to come from the same source as the chat's main model.

• The high level serves the hardest tasks.
• The medium level serves tasks of medium difficulty.
• The low level serves the simplest tasks.

Which effort level a delegated task uses is decided by the main model that initiates the delegation, based on the task's complexity; context compaction stays consistent with the chat's main model and uses the main model of the chat it belongs to. In the effort level area of "Default models", click "Modify", pick a source first, then choose a model and save. When "Follow this chat's main model" is selected, that level uses the main model of the calling chat; when a level is configured but its source or model is currently unavailable, that call falls back to the chat's main model.

Model effort levels and the chat's main model are independent of each other: changing a level does not change the main model selected in the input box. Saving returns immediately while running chats pick up the new configuration in the background. It takes effect on the next call, while requests and sub-agents already in progress keep using the configuration they started with. Models that are signed out, deleted, unauthorized, or that lack a capability the task needs are explicitly reported as unavailable — they are never silently swapped for another source.

Image, video, and speech generation and the advisor are each a single global choice and do not change with the language model effort levels; see Image, Video, and Speech Generation and Advisor. Cross-source calls send the relevant task content to the service you selected. Context compaction processes the session's content.

Chat main model and thinking effort

The main model handles direct conversation and tool calls, and is selected separately in the chat input box. The main model's source, model choice, and thinking effort are each saved per chat; changing one chat does not affect other existing chats, and new chats inherit the most recently saved defaults. Switching sources lands on that source's default model (for Codex, GPT-6.1 Sol), which you can then change by hand.

Thinking effort is not the same setting as the high, medium, and low model effort levels. The available levels run from off, low, medium, and high up to extra high and max; which ones appear depends on the capabilities the model declares.

The thinking effort menu also offers Ultra, which lets Klaus proactively split tasks and delegate suitable work to sub-agents in parallel. Requests prefer the model's supported collaboration effort, then Max, then the last declared non-Ultra value; without a usable declaration, Medium is the request default. Ultra is saved separately per chat and preserves the previous native effort selection. Existing chats do not change the default for future chats; a selection in a blank new chat saves that default. Selecting Ultra again keeps it enabled; choosing a native level leaves it. Models without native levels offer "Default" to leave Ultra. Enabling Ultra while using Full access first asks you to confirm: "Use Full access" keeps the current permission, while "Continue" switches back to the default permission.

You can also change the model, the thinking effort, and the global effort levels while a chat is in progress. Once ready, the new configuration takes effect from the main turn's next reasoning step, without waiting for the final reply. Requests already sent, retries of those requests, and sub-agents, side questions, title generation, and maintenance tasks already started keep using the configurations they captured; switching never ends background preview services or clears chat history.

The input box selector shows the saved choice. Switching models shows no "preparing" prompt — the engine captures the new configuration on the next reasoning step; if preparing or saving fails, the reason is shown inside the input box. When the connection drops or it cannot be confirmed that the engine published the change, Klaus never quietly keeps sending with the old model. Reselecting or retrying checks the engine's record before preparing the latest choice again.

Codex fast mode

When a Codex model is selected, the composer's model menu has a fast mode switch: faster responses at higher usage. The lightning icon before the model name is always shown, outlined when off and filled when on. The setting is saved per chat and also becomes the default for new chats; it has no effect while another source is selected and returns when you switch back to Codex. Other sources do not show the switch.

Message predictions

An empty composer suggests the next message you are likely to send, generated by the model this chat already uses — any model source works, with no extra subscription or sign-in. Press Tab to accept it as a draft you can still edit before sending. No prediction appears while a turn is still running or plan mode is on. To turn it off, disable "Show predictions" under "Settings → Preferences → Editor".

Viewing quota

The usage entry at the bottom of the sidebar shows quota for the source the current conversation uses: what remains, when it resets, and the plan; some sources separate personal and organization quota, and sources measured over several windows (such as five hours and weekly) show each window. It follows the conversation you have open and refreshes when you switch; custom API keys show only the model and a billing note.