source-lm
Bulk-uploads chat exports, JSON, or YouTube videos into NotebookLM at once.
source-lm is a Chrome extension that takes a Telegram export, a support-ticket dump, or any JSON with records and packs it into Markdown files sized to a 400,000-word budget — safely under NotebookLM's 500,000-word source cap — without ever splitting one record across two files. Re-running it after the export grows uploads only the new records, since it reads its cursor back from the notebook's own source names rather than keeping local state. There's no backend: the popup builds the files in your browser and sends them straight to the notebook's own origin, so your Google session never touches a third-party server, and the code ships unminified. The free tier gives 5 bulk uploads a month.
What holds up
- +No backend — the popup builds files in your browser and sends them straight to the notebook's own origin.
- +Source-available and shipped unminified, so you can read exactly what the extension does.
- +Re-running on a grown export only uploads the new records, with no local state to drift out of sync.
Mind the limits
- −Free tier caps at 5 bulk uploads a month — heavier use needs a paid plan.
- −Chrome and Edge only — no Firefox or Safari version.
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