Tailor Gemini CLI to your workflow with hooks
Source: Google Developers Blog
JAN. 28, 2026
Tailor Gemini CLI to Your Workflow with Hooks
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.
Video demo: (Insert video embed or link here)
What Are Hooks?
Hooks are scripts or programs that Gemini CLI runs at specific, predefined points in its lifecycle. Think of them as “middleware” for your AI assistant. With hooks you can inject custom logic that executes 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.
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 <<EOF
{
"action": "deny",
"reason": "Potential secret detected"
}
EOF
fiRead more: Extensions documentation – Hooks
What Hooks Enable
- Automation – Run custom logic automatically at key points in the Gemini workflow.
- Extensibility – Package reusable behavior with the extension itself.
- Zero‑setup – Installing the extension automatically registers its hooks.
Real‑world Examples
| Extension | Hook used | What it does |
|---|---|---|
| Ralph – viral “Ralph loop” | AfterAgent | Intercepts the agent’s completion signal and forces a continuous, iterative loop, keeping Gemini working on tough problems and refreshing its context between attempts. |
| galz10pickle‑rick – Ralph loop with a software‑development lifecycle | AfterAgent (and others) | Implements a more structured, iterative development process, adding a touch of character and humor while still leveraging the same loop mechanics. |
Why It Matters
Hooks turn Gemini CLI from a reactive assistant into a tireless, autonomous worker that can:
- Persistently tackle difficult tasks.
- Automatically refresh its context between iterations.
- Follow custom workflows (e.g., development lifecycles, data‑processing pipelines).
By embedding hooks in extensions, developers can ship sophisticated, plug‑and‑play automation that enhances Gemini’s capabilities without any extra user effort.
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@latestTo 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.