read_file
Read-only
Read file contents from local paths or URLs with pagination support for text, PDF, Excel, and image formats. Extract PDF text as markdown and view images as base64-encoded content.
Instructions
Read contents from files and URLs.
Read PDF files and extract content as markdown and images.
Prefer this over 'execute_command' with cat/type for viewing files.
Supports partial file reading with:
- 'offset' (start line, default: 0)
* Positive: Start from line N (0-based indexing)
* Negative: Read last N lines from end (tail behavior)
- 'length' (max lines to read, default: configurable via 'fileReadLineLimit' setting, initially 1000)
* Used with positive offsets for range reading
* Ignored when offset is negative (reads all requested tail lines)
Examples:
- offset: 0, length: 10 → First 10 lines
- offset: 100, length: 5 → Lines 100-104
- offset: -20 → Last 20 lines
- offset: -5, length: 10 → Last 5 lines (length ignored)
Performance optimizations:
- Large files with negative offsets use reverse reading for efficiency
- Large files with deep positive offsets use byte estimation
- Small files use fast readline streaming
When reading from the file system, only works within allowed directories.
Can fetch content from URLs when isUrl parameter is set to true
(URLs are always read in full regardless of offset/length).
FORMAT HANDLING (by extension):
- Text: Uses offset/length for line-based pagination
- Excel (.xlsx, .xls, .xlsm): Returns JSON 2D array
* sheet: "Sheet1" (name) or "0" (index as string, 0-based)
* range: ALWAYS use FROM:TO format (e.g., "A1:D100", "C1:C1", "B2:B50")
* offset/length work as row pagination (optional fallback)
- Images (PNG, JPEG, GIF, WebP): Base64 encoded viewable content
- PDF: Extracts text content as markdown with page structure
* offset/length work as page pagination (0-based)
* Includes embedded images when available
IMPORTANT: Always use absolute paths for reliability. Paths are automatically normalized regardless of slash direction. Relative paths may fail as they depend on the current working directory. Tilde paths (~/...) might not work in all contexts. Unless the user explicitly asks for relative paths, use absolute paths.
This command can be referenced as "DC: ..." or "use Desktop Commander to ..." in your instructions.Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | ||
| isUrl | No | ||
| offset | No | ||
| length | No | ||
| sheet | No | ||
| range | No | ||
| options | No |