Basic Commands

# Basic start - interactive mode
$ gemini

# Start with a specific prompt
$ gemini "Explain the architecture of this project"

# Start with a specific model
$ gemini --model gemini-2.5-flash

# Pipe input from another command
$ cat error.log | gemini "Analyze these errors"

# Understanding your project
> What does this project do?
> Explain the folder structure
> What frameworks and libraries does this project use?

# Finding specific code
> Where is the user authentication logic?
> Find all API endpoints in this project
> Show me where environment variables are used

# Understanding code
> Explain how the database connection pool works
> What does the middleware chain look like?
> Trace the request flow for POST /api/users

# Simple edits
> Add error handling to the fetchUser function in
  src/services/user.ts

# Creating new files
> Create a new utility file for date formatting
  with functions for relative time, ISO format,
  and locale-aware display

# Multi-file edits
> Rename the "UserProfile" component to
  "AccountProfile" across all files

# Gemini CLI shows the diff:
--- a/src/services/user.ts
+++ b/src/services/user.ts
@@ -15,6 +15,12 @@
 async function fetchUser(id: string) {
+  try {
     const response = await api.get(`/users/${id}`);
     return response.data;
+  } catch (error) {
+    if (error.status === 404) {
+      throw new UserNotFoundError(id);
+    }
+    throw new ApiError('Failed to fetch user', error);
+  }
 }

Apply changes? [y/n/e(dit)]: y
✓ Changes applied to src/services/user.ts

# Run tests
> Run the test suite and fix any failing tests

# Build the project
> Build the project and fix any compilation errors

# Install dependencies
> Install the axios library and update the imports

# Gemini CLI asks permission:
I'd like to run: npm test
Allow? [y/n]: y

Running npm test...
PASS src/utils/date.test.ts
FAIL src/services/user.test.ts
  ✗ should handle missing user gracefully

I see a failing test. Let me fix it...

# Start in sandbox mode (read-only)
$ gemini --sandbox

# In sandbox mode, Gemini CLI can:
✓ Read files and understand your codebase
✓ Answer questions about your code
✓ Suggest changes (shown but not applied)
✓ Search for patterns and dependencies

# In sandbox mode, Gemini CLI cannot:
✗ Modify or create files
✗ Run shell commands
✗ Install packages

# Reference specific files in your prompt
> Look at src/auth/login.ts and add rate limiting

# Start a new conversation (clear context)
> /clear

# Check current context usage
> /status

# Focus on specific directories
> Only look at files in the src/api/ directory
  and tell me about the endpoint structure