Tailor Gemini CLI to your workflow with hooks

Source: Google Developers Blog

Introduction

JAN. 28, 2026

Efficiency in the age of agents isn’t just about writing code faster; it’s about building custom tools that adapt to your specific environment. Whether you need to:

• Inject custom project context
• Enforce strict security policies
• Automate testing workflows

a one‑size‑fits‑all agent often falls short.

That’s why we’re introducing Gemini CLI hooks, a powerful new way to control and customize the agentic loop—allowing you to tailor the behavior of Gemini CLI without ever touching its source code.

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What Are Hooks?

Hooks are scripts or programs that Gemini CLI executes at specific, predefined points in its lifecycle. Think of them as “middleware” for your AI assistant. With hooks you can inject custom logic that runs synchronously within the agent loop, giving you the ability to:

• Add context – Insert relevant information (e.g., recent Git commits, Jira tickets, or local documentation) before the model processes a request.
• Validate actions – Review and block potentially dangerous operations before they are executed, iterating until requirements are met and improving model performance.
• Enforce policies – Automatically apply organization‑wide security and compliance rules.
• Log and optimize – Track tool usage and dynamically adjust tool selection to boost accuracy while reducing token costs.
• Send notifications – Get alerts when Gemini CLI is idle, awaiting input, or requires a tool confirmation.

By configuring hooks, you can tailor Gemini CLI to the needs of any project. When an event fires, the CLI pauses until your hook finishes, ensuring that your custom logic is always respected. This opens the door to building on top of Gemini CLI in any way you see fit.

A Compelling Example: Automated Secret Scanning

One of the most practical uses for hooks is creating a security safety net. With a BeforeTool hook, you can prevent the AI from accidentally writing sensitive data—such as API keys or passwords—into your codebase.

Tip: To see all the available hook event types in Gemini CLI, refer to the official documentation.

Hook Script (.gemini/hooks/block-secrets.sh)

#!/usr/bin/env bash
# Read hook input from stdin
input=$(cat)

# Extract content being written using jq
content=$(echo "$input" | jq -r '.tool_input.content // .tool_input.new_string // ""')

# Check for common secret patterns
if echo "$content" | grep -qE 'api[_-]?key|password|secret|AKIA[0-9A-Z]{16}'; then
  # Return structured denial to the agent
  cat
fi

• Hooks reference –

What Hooks Enable

Hooks open up a new wave of possibilities for Gemini CLI extensions. By tapping into lifecycle events (e.g., AfterAgent), an extension can modify or extend Gemini’s behavior automatically.

Example: The Ralph Extension

• Repo:
• Technique: Implements the “Ralph loop” by using an AfterAgent hook.
• How it works:
  1. The hook intercepts the agent’s completion signal.
  2. It forces the agent back into a continuous, iterative loop.
  3. Gemini CLI refreshes its context between attempts, preventing “context rot” during long sessions.

Result: Gemini CLI becomes a tireless, autonomous worker that keeps working until the task is truly finished.

Example: Galz10pickle‑Rick Extension

• Link:
• Technique: A more rigid, iterative software‑development‑lifecycle version of the Ralph loop, infused with character and humor.

Takeaway: By packaging hooks inside extensions, developers can deliver sophisticated, self‑sustaining workflows that transform Gemini CLI from a reactive assistant into a proactive, long‑running automation engine. Explore the documentation and start building your own hook‑enabled extensions today.

Get Started

Hooks are enabled by default in Gemini CLI as of v0.26.0+. Update to the latest version by running:

npm install -g @google/gemini-cli@latest

To dive deeper and start building your first hook, check out our official documentation:

• Introduction to hooks – An overview of the core concepts and events.
• Writing Your First Hook – A comprehensive example.
• Hooks Technical Reference – Detailed input and output schemas for every event type.
• Best Practices & Security – Performance optimization and threat‑mitigation strategies.

Try it out today and let us know how you’re tailoring Gemini CLI to your workflow on our GitHub repository or on socials!

You can also follow Gemini CLI on X to stay up to date with the latest news and announcements.