Proactive Mode (KAIROS)

KAIROS is an experimental autonomous mode where Claude Code stays alive between user messages. It acts on its own initiative, changes behavior based on terminal focus, and is explicitly biased toward action.

KAIROS feature flag name <tick> keep-alive signal

! KAIROS is experimental: not available in standard builds

The KAIROS / PROACTIVE feature flag exists in the source code but is not enabled in standard Claude Code releases. This page documents the architecture as found in the code.

How it works

<tick> prompts

Instead of waiting for user input, Claude receives periodic <tick> signals. These keep the agent alive and trigger autonomous decision-making.

Bias toward action

The prompt explicitly instructs Claude to read files, search, execute tests, make changes, and commit without asking. The default is to do, not to ask.

SleepTool is mandatory

If there is nothing useful to do, Claude MUST call the SleepTool. It is never allowed to respond with 'still waiting' or idle text without sleeping first.

Behavior by terminal focus

Terminal unfocused

→ Acts fully autonomously
→ Decides, explores, commits, pushes
→ No prompts or confirmations
→ Maximum initiative mode

Terminal focused

→ More collaborative behavior
→ Shows options to the user
→ Asks before large changes
→ Reduced initiative mode

The tick loop

<tick> signal received

The system sends a tick to keep the agent alive.

Assess terminal focus

Is the terminal focused? Determines collaboration vs. autonomy level.

Find useful work

Scan for files to read, tests to run, changes to make, commits to push.

Work is available?

Execute it autonomously (unfocused) or show options (focused).

No work available

Must call SleepTool. Cannot output idle text.

Wait for next tick

Sleep until the next tick signal arrives.

→ This is how agentic workflows are designed to work

The KAIROS architecture reveals the intended end-state for Claude Code: a persistent agent that works continuously in the background, not just when you type. The current interactive mode is a stepping stone toward this model.