File Upload Implementation

Overview

File upload uses HTTP Resumable Upload – the reliable, headless method.

HTTP Resumable Upload

Implementation

Uses Google's 3-step resumable upload protocol:

1. Register source intent (RPC: o4cbdc) → get SOURCE_ID
2. Start upload session (POST to /upload/_/) → get upload URL
3. Stream file content → upload URL (memory-efficient streaming)

Code Structure

• SourceMixin._register_file_source() - Step 1: Register and get SOURCE_ID
• SourceMixin._start_resumable_upload() - Step 2: Get upload URL
• SourceMixin._upload_file_streaming() - Step 3: Stream file content
• SourceMixin.add_file() - Public API that orchestrates all 3 steps

Usage

Python:

from notebooklm_tools.core.client import NotebookLMClient

with NotebookLMClient() as client:
    result = client.add_file(notebook_id="...", file_path="document.pdf")
# Returns: {"id": "source-id", "title": "document.pdf"}

CLI:

nlm source add <notebook-id> --file document.pdf

MCP:

source_add(notebook_id="...", source_type="file", file_path="/path/to/file.pdf")

Supported File Types

• Documents (.pdf, .txt, .md, .docx, .csv)
• Ebooks (.epub)
• Audio (.mp3, .m4a, .wav, .aac, .ogg, .opus)
• Video (.mp4)
• Images (.jpg, .jpeg, .png, .gif, .webp)

Advantages

• ✅ No Chrome dependency
• ✅ Works in headless/server environments
• ✅ Memory-efficient streaming for large files
• ✅ Faster and more reliable
• ✅ No browser fingerprinting issues

Testing

# Create a test file
echo "Test content" > test.txt

# Upload the file
nlm source add <notebook-id> --file test.txt

# Verify it was added
nlm source list <notebook-id>

Troubleshooting

"File not found"

• Cause: The file path doesn't exist or is inaccessible
• Fix: Check the file path spelling and permissions

"Unsupported file type"

• Cause: File extension is not in the supported list
• Fix: Convert the file to a supported format

Upload times out

• Cause: Large file or slow connection
• Fix: The upload may still complete on the backend; check notebook sources before retrying

Historical Note

A browser-based upload fallback using Chrome automation was previously available (--browser flag) but has been removed. NotebookLM's UI now uses the File System Access API which cannot be automated via CDP. The HTTP method is more reliable anyway.