Preview
This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the Service Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see the launch stage descriptions.
This document describes agent mode in Gemini Code Assist.
Agent mode is available in the VS Code and IntelliJ integrated development environments (IDEs). To start using agent mode, see Use the Gemini Code Assist agent mode.
With agent mode, you can do any of the following and more:
- Ask questions about your code.
- Use context and built-in tools to improve generated content.
- Configure MCP servers to extend the agent's abilities.
- Get solutions to complex tasks with multiple steps.
- Generate code from design documents, issues, and
TODOcomments. - Control the agent behavior by commenting on, editing, and approving plans and tool use during execution.
How agent mode works
In agent mode, your prompt is sent to the Gemini API with a list of tools that are available. The Gemini API processes the prompt and returns a response. The response might be a direct answer or a request to use an available tool.
When a tool is requested, the agent prepares to use the tool and checks to see if it is allowed to use the tool with or without explicit permission:
- For tool requests that modify the file system, or perform mutating operations on any resources, Gemini will ask you to allow the operation unless you have configured Gemini to always allow the tool or tools.
- Tool requests that are read-only might not ask for permission before completing the task.
When asked to allow the use of a tool, you can choose to allow or deny the operation. The agent might also give you options to always allow a tool or server or allow similar operations. For more information, see Always allow agent actions.
Once permission to use the tool is given or self-granted, the agent uses the tool to complete the required action, and the result of that action is sent back to the Gemini API. Gemini processes the result of the tool action and generates another response. This cycle of action and evaluation continues until the task is complete.
For complex tasks, Gemini might show a high-level plan for your approval. You can fine tune the plan and ask questions in chat before beginning the process. Once you are happy with the plan, you can approve it. After you approve the plan, the agent starts working on the first task, and will ask you for clarifications or permissions as needed as it executes the plan.
Agent mode context
Context allows an agent to generate better responses for a given prompt. Context can be taken from files in your IDE, files in your local system folders, tool responses, and your prompt details.
Depending on your IDE and settings, different contexts might be available to the agent.
The following tabs detail how context is gathered for different IDEs.
VS Code
The following methods of getting context are usually available to Gemini Code Assist in agent mode:
- Information in your IDE workspace.
- Tool responses from built-in tools like grep, terminal, file read, or file write.
- Google Search responses.
- Content from a given URL provided in a prompt or by a tool.
- Context files you create in Markdown.
IntelliJ
The following methods of getting context are usually available to Gemini Code Assist in agent mode:
- Information in your IDE project including your files, indexed symbols and usage of symbols in your project.
- Tool responses from built-in tools like grep, file read, or file write.
- IntelliJ version control.
- Configured MCP servers and tools
- Context files you create in Markdown.
You can see the context available to the agent in the context drawer in the agent mode chat prompt area.
![[Google Cloud Documentation]](https://www.gstatic.com/devrel-devsite/prod/v0f3a5b8b76e4a120372a69044e02756e703b6140f9f1812c6e4a0407b19864b7/clouddocs/images/lockup_full_color.svg){kind=link}
![[]](https://docs.cloud.google.com/_static/clouddocs/images/icons/products/gemini-color.svg){kind=link}
![[Agent mode context drawer.]](https://cloud.google.com/static/gemini/images/intellij-agent-mode-welcome-context-drawer.png){kind=link}
Tools
Tools are a broad category of services that an agent can use for context and actions in its response to your prompt. Tools allow agents to access up-to-date information through function calling to API endpoints or to other agents. Tools might only offer one function, or they might offer multiple related functions.
Some example tools are built-in tools like grep and file read or write, local or remote Model Context Protocol (MCP) servers and their executable functions, and RESTful API calls.
Built-in tools
In agent mode, Gemini has access to your built-in system tools. Select your IDE to view a list of built-in tools available to Gemini in agent mode.
VS Code
All of the Gemini CLI built-in tools are available to agent mode in Gemini Code Assist.
IntelliJ
read_file- Retrieves the text content of a file using its absolute path.
write_file- Writes the given text to a specified file, creating the file if it doesn't exist.
analyze_current_file- Analyzes the open file in the editor for errors and warnings.
find_files- Finds the absolute path to files given a filename or a part of the path
grep- Finds all files inside the project that contain a given text pattern or regular expression.
list_files- Lists all files and directories in a given absolute path.
resolve_symbol- Resolves a specific symbol reference to its original declaration.
find_usages- Searches the project for all references to a given symbol declaration.
git- Runs a Git command-line interface (CLI) command and returns the result.
list_vcs_roots- Returns all Version Control System (VCS) roots, such as Git repositories, in the current project.
Limitations
Some features of standard Gemini Code Assist chat might not be available in agent mode or might work differently than they do in standard chat.
Recitation is not available in agent mode. While in agent mode, Gemini doesn't cite sources and you can't disable code suggestions that match cited sources.
What's next
- Use the Gemini Code Assist agent mode.
- Learn about agent mode quotas.