thank you so much Karen, it feels like the exact same story I have been doing for the past two weeks but for scheduling the notes. I just built and successfully tested the chrome plugin for myself as I was struggling with n8n workflow so I vibe-coded with Google Gemini 3.. I will publish more about it in next weeks
This is exactly how I started building my first Chrome extensions, except I didn't use AI, just Googling Chrome API documents and grabbing those pesky Substack API calls from the web developer console.
With AI this all becomes so much easier. And having the data cached locally makes filtering, transformation and visualization much faster.
I want to track how many women are on the leaderboards. I thought i could maybe use this to pull the list out and then maybe manually set the gender and put it into a data base that checks for new people
This would involve scraping the leaderboards or using Substack’s undocumented API. This is technically against Substack’s TOS but IMO would be pretty low risk if you’re just sharing stats and not, say, selling them in a report.
Great article! The debugging section was especially helpful – the nextCursor camelCase gotcha and membership_state: "subscribed" vs "active" would have cost me hours.
Quick tip for exploring APIs: Instead of clicking around in DevTools, a simple bash script can test endpoints systematically:
bash#!/bin/bash
COOKIE="substack.sid=..."
for e in subscriptions trending?limit=5 reader/feed inbox; do
Thank you for doing this, and sharing not only the extension but the prompt and all your learnings.
I think I'll have Claude gin up something that I can play around with, and knowing all the headaches ahead of time is so valuable.
I love what you're doing, and fwiw, we seem to be soul sisters in terms of how we approach coding with Claude. I was repeatedly nodding as I read along!
Thanks for making this extension and sharing your process Karen! I've been trying to figure out the best way to build something that integrates with Substack, so this is super helpful.
Great article, Karen. Three things come to my mind:
1. I have witnessed a handful of projects shut down due to the legal concerns. Bringing legal in early is recommended when building a product.
2. The innovation often comes from working within constraints.
3. I personally love this initiative. I follow a wide range of topics, and I am mindful of inbox overload. When subscriptions pile up, I sometimes end up reading less, not more.
Thank you so much for the thoughtful comment! Agree it’s important to consider legal and compliance issues in the earliest stages of development…I learned this the hard way. 😆
thank you so much Karen, it feels like the exact same story I have been doing for the past two weeks but for scheduling the notes. I just built and successfully tested the chrome plugin for myself as I was struggling with n8n workflow so I vibe-coded with Google Gemini 3.. I will publish more about it in next weeks
Awesome! ❤️ I’m looking forward to learning about your new tool!
omg this is exactly what I wanted for Christmas! You rock Karen!
Thank you! 🙏 🥰 And now I’m curious how many subscriptions you’re trying to manage! 🤔
Me too 😂
This is awesome article, Karen!
This is exactly how I started building my first Chrome extensions, except I didn't use AI, just Googling Chrome API documents and grabbing those pesky Substack API calls from the web developer console.
With AI this all becomes so much easier. And having the data cached locally makes filtering, transformation and visualization much faster.
Thank you! 🙏 And 💯…without AI, this would have taken me at least a month!
This looks extremely interesting.
I am going to check it out to manage CLAG subscriptions, but also I might try to build a chrome extension myself.
You should definitely try building your own! It’s more straightforward than I thought it would be, and you can get exactly what you want!
I want to track how many women are on the leaderboards. I thought i could maybe use this to pull the list out and then maybe manually set the gender and put it into a data base that checks for new people
This would involve scraping the leaderboards or using Substack’s undocumented API. This is technically against Substack’s TOS but IMO would be pretty low risk if you’re just sharing stats and not, say, selling them in a report.
No i would just be tracking the number of women on the list and reporting it on Substack.
I mean I can do it by counting manually....
Were you thinking of aggregating numbers across all the bestselling lists?
Great article! The debugging section was especially helpful – the nextCursor camelCase gotcha and membership_state: "subscribed" vs "active" would have cost me hours.
Quick tip for exploring APIs: Instead of clicking around in DevTools, a simple bash script can test endpoints systematically:
bash#!/bin/bash
COOKIE="substack.sid=..."
for e in subscriptions trending?limit=5 reader/feed inbox; do
echo -n "Testing $e ... "
body=$(curl -s "https://substack.com/api/v1/$e" -H "Cookie: $COOKIE")
if echo "$body" | head -c 1 | grep -q '{'; then
echo "✅ OK"
echo "$body" > "${e//\//_}.json"
elif echo "$body" | grep -q "DOCTYPE"; then
echo "⚠️ Doesn't exist"
else
echo "🔒 Not authorized"
fi
done
JSON = works. HTML = doesn't exist. Then grep through the files like you did.
Thank you so much for the script! Less clicking = good 😁
This is perfect! I was looking for something like that from those creators who schedule notes. But this is great, and free? I must try this! 🚀
Amazing! If you try it, let me know how it goes!
Thank you for doing this, and sharing not only the extension but the prompt and all your learnings.
I think I'll have Claude gin up something that I can play around with, and knowing all the headaches ahead of time is so valuable.
I love what you're doing, and fwiw, we seem to be soul sisters in terms of how we approach coding with Claude. I was repeatedly nodding as I read along!
That’s awesome! If you build your own (exactly what I would do 😁), I’d love to hear how it turns out!
You dont cease to amaze me!
Thank you! ❤️
This a terrific tool! Just started tagging and adding newsletters to collections. Love it!
Awesome! ❤️🙏 Let me know if you have any questions!
You are so sweet!
I am going to be looking at more of your articles today!
💛✨🔆
Thank you! ❤️🙏
This is cool!! Thanks for sharing it
You’re very welcome!
Wow! This is pretty impressive. Hats off to you. I love the ability to organize newsletters in different collections.
Thank you!!🤗 If you end up trying the tool, I’d love to hear your feedback!
Thanks for making this extension and sharing your process Karen! I've been trying to figure out the best way to build something that integrates with Substack, so this is super helpful.
You’re very welcome! 🤗
I definitely need this! Can’t wait to try it when I’m back on desktop later today!
Let me know how it works for you! 🙏🤗
This is a masterclass in pragmatic product pivoting. 👏👏👏
Thanks so much! 🙏❤️
Great article, Karen. Three things come to my mind:
1. I have witnessed a handful of projects shut down due to the legal concerns. Bringing legal in early is recommended when building a product.
2. The innovation often comes from working within constraints.
3. I personally love this initiative. I follow a wide range of topics, and I am mindful of inbox overload. When subscriptions pile up, I sometimes end up reading less, not more.
Thank you so much for the thoughtful comment! Agree it’s important to consider legal and compliance issues in the earliest stages of development…I learned this the hard way. 😆