What is agentic coding?

Agentic coding is a software development approach where autonomous AI agents plan, write, test, and modify code with minimal human intervention. Unlike traditional AI coding assistants that wait for a user to type code or ask a question, agentic coding tools take a high-level instruction and execute it. These agents function more like a skilled contractor than a passive consultant. They understand the goal, break it down into steps, and execute the necessary actions to complete the work.

While standard AI tools might suggest snippets or complete single functions, agentic code solutions can manage complex workflows. They can navigate file systems, manage dependencies, and run terminal commands. If an agent writes code that causes an error, it can read the error message, reason through the problem, and apply a fix automatically. This shift from "chatting with AI" to "assigning tasks to AI" helps developers focus on architecture and logic while the agent handles implementation details.

AI coding with Gemini CLI - Google's terminal agentic coding tool

What is a coding agent?

A coding agent is an advanced software program powered by a large language model (LLM) that performs software development tasks autonomously. These agents don’t just generate text; they use a process often called a "reason and act" loop. When given a goal, the agent breaks the request into smaller, manageable sub-tasks. It then uses specific tools to accomplish these tasks, such as accessing the file system, running bash commands, or interacting with version control systems.

The defining feature of a coding agent is its iterative feedback loop. It doesn’t simply output code and stop. Instead, it performs automated operations to verify its work. For example, an agent might write a test case, run the code, observe a failure, and then rewrite the code to pass the test. This ability to self-correct allows coding agents to help handle complex instructions that could otherwise confuse standard text-based AI models.

Agentic coding versus "vibe coding"

"Vibe coding" is a term that describes a coding experience characterized by a highly fluid, intuitive, and distraction-free state of flow. It refers to a method of coding where you focus entirely on the logic and creativity—the "vibe" of the application—without getting bogged down by syntax errors or boilerplate code.

Agentic coding, by contrast, is the technological methodology that often enables this state. It’s the structured, autonomous process where the AI handles the execution. While vibe coding is the goal or the feeling, agentic coding is the engine. "Agentic vibe coding" implies using these autonomous agents to help handle the heavy lifting, allowing you to remain in that creative flow state without interruption.

Best practices for secure agentic coding workflows

Adopting agentic coding in an enterprise environment often requires more stringent security measures and governance. Since agents technically have the autonomy to edit files and execute commands, organizations must treat them with the same scrutiny applied to their own employees, hired contractors, or automated scripts.

  • Define scope and guardrails: Administrators should limit what the agent can access and stop it from running dangerous commands, like deleting databases or pushing changes straight to the live production environment.
  • Apply strict dependency governance: Security teams must ensure agents can only install software from trusted and approved sources to prevent the introduction of malicious dependencies or "typosquatting" attacks.
  • Require proof of compliance: Organizations should set up agents to log their actions and decision-making processes, creating an audit trail that proves code changes meet compliance standards.
  • Add human checks to workflows: Before any code an AI agent makes goes into the main project, someone on the team should review it using the standard pull request process.
  • Use enterprise visibility tools: Companies can use centralized dashboards to track agent activity, usage quotas, and performance metrics across different development teams.
  • Monitor for new classes of vulnerabilities: Security teams should watch for prompt injection attacks or "hallucinated" code paths that might introduce logic errors unique to AI-generated software.
  • Run controlled red team exercises: Security professionals can simulate attacks on the agentic workflow to see if the agent can be tricked into writing insecure code or revealing sensitive data.
  • Perform layered security testing: Developers should use static application security testing (SAST) and dynamic application security testing (DAST) tools to automatically scan agent-generated code.
  • Continuously refine controls: Teams should regularly update their security policies and the instructions (system prompts) given to AI agents, based on what they find from checks and tests.

Benefits of using agentic coding

Increases efficiency and scalability

Agents can quickly handle repetitive coding tasks, allowing teams to build larger systems without increasing headcount.

Automates complex workflows autonomously

An agent can manage multi-step processes, such as upgrading a library across multiple files, without needing constant human input or guidance.

Frees up developers to focus on high-value tasks

By offloading implementation details, engineers can dedicate their mental energy to complex problem-solving and strategic architecture.

Improved code quality and security reviews

Agents can consistently apply style guides and security best practices that humans might occasionally miss.

Faster feature delivery and automated bug fixing

Agents can identify the root cause of a bug and propose a fix in minutes, helping to shorten the development lifecycle.

Reduced developer workload and focus on high-level design

Developers can act more like architects, defining the structure while the agent can lay the foundation, reducing burnout.

Agentic coding with Google Cloud

Google Cloud offers tools that support the agentic coding workflow, designed to bring autonomy to your development environment. The core of this offering revolves around Gemini CLI, Google Antigravity, and Gemini Enterprise, which can transform how developers interact with their codebase.

How Gemini CLI implements agentic coding

Gemini CLI changes the dynamic from asking for help to assigning work. Here is how it manages agentic tasks:

  • Tool use: The agent can autonomously run commands like ls, grep, and cat. It can also write directly to files. Instead of suggesting you run a test, it runs npm test itself and reads the logs.
  • Memory and context: It supports a GEMINI.md file in your project root. This file acts as long-term memory or a system prompt where you define coding standards, architecture rules, or specific "do not do this" instructions that the agent follows for every task.
  • Self-correction: If the agent writes code that fails a build, it sees the error message in the terminal. It then reasons about why the failure occurred and attempts a different solution automatically.
  • Extensibility (MCP): It supports the Model Context Protocol (MCP). This allows you to connect the agent to external data sources like PostgreSQL, GitHub, or Slack, so it can fetch context from outside your local file system.

Use cases for Gemini CLI

Gemini CLI adapts to the stage of your development lifecycle, offering distinct advantages whether you are building from scratch or maintaining an established codebase.

Greenfield development (New applications)

When starting a new project, Gemini CLI can act as a force multiplier for rapid prototyping and architectural setup.

  • Scaffolding and initialization: You can instruct the agent to set up a complete project structure, including configuration files, directory hierarchies, and initial dependencies. For example, a single prompt can generate a Python Flask application with a connected database and basic routing.
  • Boilerplate reduction: Developers can assign the agent to generate repetitive code structures, such as data models, API endpoints, or form validation logic, allowing the human lead to focus on unique business logic.
  • Rapid prototyping: Teams can quickly validate ideas by describing a feature in natural language. The agent can build a functional prototype, run it, and iterate on it based on feedback, significantly shortening the time between concept and demo.

Brownfield modernization (Existing applications)

For legacy or established applications, Gemini CLI helps streamline maintenance, refactoring, and knowledge transfer.

  • Refactoring and optimization: You can task the agent with modernizing specific modules, such as converting older JavaScript files to TypeScript or updating deprecated API calls. The agent can read the existing code, apply the requested changes, and verify that the logic remains consistent.
  • Test generation and coverage: To improve stability, developers can ask the agent to analyze a file and write comprehensive unit tests. By referencing a GEMINI.md file with your testing conventions, the agent ensures the new tests align with your team's standards.
  • Documentation and onboarding: Large codebases can be difficult for new engineers to navigate. The agent can scan directories to generate up-to-date documentation, explain complex functions, or create architectural diagrams, making it easier for teams to understand and maintain the software.

Greenfield development (New applications)

When starting a new project, Gemini CLI can act as a force multiplier for rapid prototyping and architectural setup.

  • Scaffolding and initialization: You can instruct the agent to set up a complete project structure, including configuration files, directory hierarchies, and initial dependencies. For example, a single prompt can generate a Python Flask application with a connected database and basic routing.
  • Boilerplate reduction: Developers can assign the agent to generate repetitive code structures, such as data models, API endpoints, or form validation logic, allowing the human lead to focus on unique business logic.
  • Rapid prototyping: Teams can quickly validate ideas by describing a feature in natural language. The agent can build a functional prototype, run it, and iterate on it based on feedback, significantly shortening the time between concept and demo.

Brownfield modernization (Existing applications)

For legacy or established applications, Gemini CLI helps streamline maintenance, refactoring, and knowledge transfer.

  • Refactoring and optimization: You can task the agent with modernizing specific modules, such as converting older JavaScript files to TypeScript or updating deprecated API calls. The agent can read the existing code, apply the requested changes, and verify that the logic remains consistent.
  • Test generation and coverage: To improve stability, developers can ask the agent to analyze a file and write comprehensive unit tests. By referencing a GEMINI.md file with your testing conventions, the agent ensures the new tests align with your team's standards.
  • Documentation and onboarding: Large codebases can be difficult for new engineers to navigate. The agent can scan directories to generate up-to-date documentation, explain complex functions, or create architectural diagrams, making it easier for teams to understand and maintain the software.

Google Antigravity: The agent-first platform

Google Antigravity represents a shift from an IDE with an assistant to a dedicated agentic development platform. Powered by Gemini 3, it treats AI agents as primary workers rather than simple helpers.

  • Manager view (mission control): Developers can use a centralized dashboard to spawn, orchestrate, and observe multiple agents working in parallel across different workspaces. You can assign one agent to research documentation while another refactors a codebase.
  • Verifiable artifacts: Instead of opaque logs, Antigravity agents generate structured "Artifacts"—verifiable records of their plans, code changes, and test results. This can provide transparency, allowing developers to audit the agent's reasoning and "proof of work" quickly.
  • Browser and terminal autonomy: Antigravity agents can possess the ability to control the browser for visual verification and execute complex terminal commands, enabling end-to-end task completion that includes deployment and testing.

Gemini Enterprise: Scaling with security

For organizations deploying agents at scale, Gemini Enterprise helps provide the necessary layer of governance and integration.

  • Centralized guardrails: Administrators can define policy-as-code that agents must adhere to, ensuring that no agentic workflow violates company compliance or security standards.
  • Private knowledge grounding: Agents can be grounded in your organization's private codebase and documentation, allowing them to write code that respects internal libraries and architectural patterns without leaking data.
  • Indemnification and compliance: Gemini Enterprise can offer intellectual property indemnification and meets rigorous compliance certifications, making it safe for large enterprises to adopt agentic coding in production environments.

Using an AI chatbot versus an agentic coding agent

To understand the power of agentic coding, compare a standard AI chat experience with Gemini CLI agent workflow.

Standard AI chat experience:

  1. You: "How do I add a rate limiter to my Express app?"
  2. AI: "Here is a code snippet using express-rate-limit..."
  3. You: Copy the code, open your editor, paste the code, run the server.
  4. You: See a crash. Copy the error message.
  5. You: Paste the error back to the AI...

Agentic Gemini CLI:

You (in terminal): gemini "Add a rate limiter to the server using express-rate-limit and ensure it passes tests."

Gemini CLI:

  • Reads package.json to check dependencies.
  • Runs npm install express-rate-limit.
  • Edits server.js to import and configure the middleware.
  • Runs npm test.
  • (If test fails) Reads the error log, edits the code again, and runs the test again.

Final Output: "Task complete. I installed the package and updated server.js. Tests are passing."

How to get Gemini CLI

Gemini CLI is an open-source tool that is separate from the standard Google Cloud SDK.

Installation: You need Node.js (version 18 or higher) installed.

  • Bash
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Authentication: Run the command once to sign in with your Google account. No API key is needed for the free tier.

  • Bash
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