Filesystem Operations

Interact with the browser VM’s filesystem to upload, download, read, and write files.

When to Use

Use this skill when you need to:

• Upload test data or fixtures to browser VMs for automation
• Download generated files like screenshots, PDFs, or reports
• Provide configuration files to scripts running in the VM
• Process data by uploading input, running scripts, and downloading output
• Manage files and directories in the browser VM filesystem
• Transfer artifacts between local machine and browser VM

Prerequisites

See prerequisites.md for Kernel CLI setup.

Note: When using --path or --src flags in the commands below, these flags are required and must be provided with a value.

Directory Operations

Create Directory

kernel browsers fs new-directory <session_id> --path /tmp/mydir

# With custom permissions
kernel browsers fs new-directory <session_id> --path /tmp/mydir --mode 0755

Delete Directory

kernel browsers fs delete-directory <session_id> --path /tmp/mydir

List Files

# List files in a directory
kernel browsers fs list-files <session_id> --path /tmp

# With JSON output
kernel browsers fs list-files <session_id> --path /tmp -o json

Get File/Directory Info

# Get metadata for a file or directory
kernel browsers fs file-info <session_id> --path /tmp/file.txt

# With JSON output
kernel browsers fs file-info <session_id> --path /tmp/file.txt -o json

File Operations

Read File

# Read file to stdout
kernel browsers fs read-file <session_id> --path /tmp/file.txt

# Save to local file
kernel browsers fs read-file <session_id> --path /tmp/file.txt -o local-file.txt

Write File

# Upload local file to VM
kernel browsers fs write-file <session_id> --path /tmp/output.txt --source local.txt

# With custom permissions
kernel browsers fs write-file <session_id> --path /tmp/output.txt --source local.txt --mode 0644

Delete File

kernel browsers fs delete-file <session_id> --path /tmp/file.txt

Move/Rename File

# Move or rename a file
kernel browsers fs move <session_id> --src /tmp/old.txt --dest /tmp/new.txt

Set Permissions

# Change file mode
kernel browsers fs set-permissions <session_id> --path /tmp/file.txt --mode 0755

# Change owner and group
kernel browsers fs set-permissions <session_id> --path /tmp/file.txt --mode 0755 --owner user --group group

Bulk Operations

Upload Files

# Upload with mapping (local:remote)
kernel browsers fs upload <session_id> --file "local.txt:/tmp/remote.txt"

# Multiple files
kernel browsers fs upload <session_id> --file "file1.txt:/tmp/file1.txt" --file "file2.txt:/tmp/file2.txt"

# Upload to destination directory
kernel browsers fs upload <session_id> --dest-dir /tmp --paths "file1.txt,file2.txt"

Upload ZIP Archive

# Upload and extract a zip file
kernel browsers fs upload-zip <session_id> --zip archive.zip --dest-dir /tmp/extracted

Note: When using --zip or --dest-dir are required and must be provided with a value.

Download Directory as ZIP

kernel browsers fs download-dir-zip <session_id> --path /tmp/data -o data.zip

Use Cases

• Test data: Upload fixtures and test data for automated tests
• Configuration: Provide config files to scripts and applications
• Data processing: Upload input, run processing scripts, download output
• Screenshots/artifacts: Collect generated files like screenshots, PDFs, reports
• Scripts: Upload custom automation or processing scripts
• File management: Organize, move, and manage files in the VM
• Batch operations: Upload/download multiple files or entire directories