getting started - using fabric to extract wisdom from a youtube video - no VTT files

[iPanini60]

What I'm trying to do:

• extract wisdom from a youtube video
• video language is dutch (so maybe that is the issue?)

When I go to the youtube video, transcripts are present, and cc can be enabled. So I assume that wisdom should be able to be distracted?

• I have yt-dlp version 2026.10.26 installed
• fabric is version 1.4.557

This is the command I am using:
fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo&t=554s" --pattern extract_wisdom --yt-dlp-args="--cookies-from-browser brave --sleep-requests 5" -o summary-3.md
no VTT files found in directory

What does the "no VTT files found in directory" mean?
When I try to list subs, this is what I get:
yt-dlp --list-subs https://www.youtube.com/watch?v=FzTXIHFOpAo&t=554s
[1] 3599
zsh: no matches found: https://www.youtube.com/watch?v=FzTXIHFOpAo
[1] + exit 1 yt-dlp --list-subs https://www.youtube.com/watch?v=FzTXIHFOpAo

Thanks for helping out!

[pballada]

Yes, the Dutch audio is the cause. Tell Fabric to fetch the Dutch captions. There are two ways, depending on which language you want the summary in:

# Summary in English: download the Dutch captions, keep the response language as is
fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo" --pattern extract_wisdom \
  --yt-dlp-args="--sub-langs nl --cookies-from-browser brave --sleep-requests 5" -o summary-3.md

# Summary in Dutch: -g sets both the caption language and the response language
fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo" -g nl --pattern extract_wisdom \
  --yt-dlp-args="--cookies-from-browser brave --sleep-requests 5" -o summary-3.md

When --yt-dlp-args contains --sub-langs, Fabric drops its own language filter and uses yours (ytDlpLangArgs in internal/tools/youtube/youtube.go).

What "no VTT files found" means: Fabric runs yt-dlp to download the captions as a .vtt file into a temporary folder. The error means yt-dlp finished without writing one.

Why that happens here: without -g (or a default language set in fabric --setup), Fabric asks yt-dlp for English only (--sub-langs en,en.*). This video has Dutch auto-captions (nl, nl-orig) plus an English track that YouTube machine-translates on request. YouTube is rate-limiting those translated tracks heavily. I ran Fabric's exact yt-dlp command (yt-dlp 2026.10.26) against your video:

[info] FzTXIHFOpAo: Downloading subtitles: en
ERROR: Unable to download video subtitles for 'en': HTTP Error 429: Too Many Requests

Fabric then retries without its language filter, but yt-dlp's default is English as well, so nothing gets written. The same command with --sub-langs nl,nl.* (which is what -g nl produces) downloaded ….nl.vtt immediately.

About your --list-subs test: that one failed for a different reason. zsh treats ? and & in an unquoted URL as special characters (zsh: no matches found, and & sent the command to the background). Quote the URL:

yt-dlp --list-subs "https://www.youtube.com/watch?v=FzTXIHFOpAo"

[iPanini60]

Thanks a ton for writing this elaborate anwser!

I'm not there yet..
I spent most part of yesterday trying to get fabric up and running on my 2018 mac mini with 32 GB of RAM. I realize that is limited hardware, but I would like to see how far I can get with that.
This turned out to be more problematic than thought.
I guess most of my problems stemm from $PATH issues. I know what it is and means, but I am by no means an expert in solving PATH issues.. I do realize there's user and system wide PATH settings.

I then realized that Fabric needs an External JS Script processor.
I managed to install Deno, but I could not get it's PATH straightened. So I set out to install Node.js, which was easier, but I then (think) I run into permission issues.

I also have an Intel NUC available and am considering installing Fabric on eithr Ubuntu or Debian. (I have both up and running on the NUC).
Is it feasible to run fabric using ssh remotely on the NUC, while piping output to macOS?

I tried copy / pasting your commands, but on my mini they fail.
I suppose there's stil missing parts in my install.

Thanks for helping out!

[hippi345]

on the mac, homebrew takes care of most of the PATH stuff for you. brew install fabric-ai yt-dlp (yt-dlp pulls in deno, that's the JS runtime it needs for youtube now), then fabric-ai --setup. brew installs it as fabric-ai, so either type that or add alias fabric='fabric-ai' to your ~/.zshrc.

and yeah the NUC works fine too. install fabric there (the README has a one-line installer for linux) plus yt-dlp and deno, run fabric --setup once over ssh, then from the mac:

ssh nuc 'fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo" -g nl --pattern extract_wisdom' > summary.md

the output comes back over ssh and lands in summary.md on the mac. --cookies-from-browser won't work there since there's no browser on the NUC, so leave it out. if ssh says command not found, use the full path from which fabric on the NUC

[iPanini60]

Thanks for helping!

In the mean time, I've been able to solve the path issue so that fabric --yt-dlp-args finds and can use deno as JS runtime, so that is a step forward. (I'd like to avoid starting over on the nuc, as that will probably be the start of the next day of losing time, and after all I should be able to get it to work properly on macOS)

But I kept running into into the dreaded "Too many requests" error.
So at the moment I'm trying to learn how to throttle yt-dlp, and use sleep intervals.

This is the command I'm issueing:
fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo" -g nl --pattern extract_wisdom \ --yt-dlp-args="--cookies-from-browser brave --sleep-interval 10 --max-sleep-interval 10 --sleep-requests 5 --limit-rate 5M --verbose " -o summary-2.md

But it doesn't seem to be working. Most of all I would like to be able to use --verbose so that at least I can see what is happening...

Post "http://localhost:11434/api/chat": net/http: request canceled (Client.Timeout exceeded while awaiting headers)
No idea what this is.. I guess it has to do with ollama. Should some command be given there to put it in serve mode or something?

[iPanini60]

One other thing:
I do have a BlackMagic eGPU sitting on the side.
If I connect it to the 2018 mini, would that help when working with Fabric / yt-dlp / ollama?

[iPanini60]

Ok, here's a little follow-up:

I've done a lot of searching and I've also connected my BlackMagicDesign eGPU.
I realize this is still all low power, low profile, but nevertheless..

• the vram of the mini is only 1536 MB
• the vram of the Radeon Pro 580 is 8 GB

I've checked and fabric install is ok (checked with fabric --version) and yt-dlp too (yt-dlp --version).
Ollama is installed and started => serve

But when I try:
fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo" -g nl --pattern extract_wisdom \ --yt-dlp-args="--cookies-from-browser brave --sleep-requests 5" -o summary-3.md

The terminal seems to hang for a very long time..
And then finally reports that there is some timeout communicating with Ollama.
Post "http://localhost:11434/api/chat": context deadline exceeded (Client.Timeout exceeded while awaiting headers)

How can I check / adjust this communication between fabric and Ollama?

Thanks for helping out!

[hippi345]

it means yt-dlp ran but didn't write any subtitle file, so fabric had nothing to read.

fabric only passes --write-auto-subs, so it only grabs youtube's auto-generated captions, not uploaded ones. and if you don't set a language it doesn't pass --sub-langs at all, so yt-dlp falls back to its default pick. for a dutch video with real (uploaded) dutch subs that combo can end up with nothing.

try telling it the language and asking for normal subs too:

fabric -y "https://www.youtube.com/watch?v=FzTXIHFOpAo" -g nl --pattern extract_wisdom \
  --yt-dlp-args="--cookies-from-browser brave --sleep-requests 5 --write-subs" -o summary-3.md

-g nl makes fabric add --sub-langs nl,nl.* for you. if it still says no VTT, run yt-dlp yourself with the same flags plus --skip-download --sub-format vtt and see what it prints, a 429 from youtube shows up there