File references

File references let you include file contents or directory trees directly in your chat messages using @path syntax. This provides quick context without manually copying content, and since the content is expanded inline before sending, it avoids tool calls—saving tokens.

Type @ followed by a file or directory path:

@src/index.ts             # Include file contents
@src/                     # Include directory tree
@./relative/path          # Relative paths
@"path with spaces.txt"   # Quoted paths (required for spaces)

References can appear anywhere in your message:

Review @src/auth.ts for security issues
Compare @old.json with @new.json
What's in @src/ that handles authentication?

Press Tab after @ to auto-complete paths:

@src/<Tab>                # Shows files in src/
@package<Tab>             # Completes to @package.json
@"Screenshot 2024<Tab>     # Completes to @"Screenshot 2024-01.png"

Completion works anywhere in the input line. Tab completion automatically adds quotes when needed for paths with spaces.

When a reference could match both a prompt and a file:

1. Prompts first: If @name matches a prompt from /prompts list, it's treated as a prompt
2. Files second: Otherwise checked as a file path
3. Directories third: If not a file, checked as a directory

To force file resolution when a prompt has the same name, use an explicit path: @./myfile

Supported: Text files (source code, config, markdown) up to 250KB.

Not supported: Binary files (images, executables, archives) show an error.

Large files are truncated at 250KB:

⚠ File 'large-file.json' was truncated (exceeds 250KB limit)

Directory references expand to a tree listing:

@src/

Expands to:

src/
├── lib/
│   ├── auth.ts
│   └── utils.ts
├── index.ts
└── config.json

Limits:

• Max depth: 3 levels
• Max items per level: 10 (shows "... (N more items)" if exceeded)
• Ignores common directories: node_modules, .git, target, dist, build

Review a file:

> Review @src/auth.ts for security issues

Compare files:

> What's different between @v1/handler.py and @v2/handler.py?

Explore structure:

> What's the structure of @infra/cdk/?

Mixed context:

> Using the config in @serverless.yml, update @src/lambda/index.ts

File references currently support:

• Text files up to 250KB (larger files are truncated)
• Directory trees up to 3 levels deep, 10 items per level
• Explicit file paths only (no glob patterns like @*.ts)
• Full file contents (no line ranges like @file.ts:10-20)
• Relative and absolute paths (no tilde expansion like @~/file)

Binary files (images, executables, archives) are not supported.

• Manage Prompts - Prompt templates also use @ syntax
• Context Management - Persistent context files