Lettertrace measures how often Claude, ChatGPT, and Gemini mention your company. But there's a catch: it's free, developer-first, bring-your-own-key, and open source.
Mathew here. I'm the founder of The Letter Company.
Today, we're debuting one of my favorite things that we've ever built. You've likely heard of AEO. Or GEO. Or AI Search. It's a popular space rife with tools. But there's been a big problem: it's pay-to-play. Even to find out how you're doing on AI Search, you need to fork over something crazy like $250/mo.
And I beg.... for what? AI search is effectively measured by a crafty cron job that orchestrates a bunch of model provider calls.
No more $250/mo fees. Now, it's free. Lettertrace is a BYOK telemetry tool for measuring how you're doing on AI search. It's open source. MIT license. Free even on our hosted version. There are no paid tiers. None. Nada. You'll never put down a credit card. We're moving beyond that. It's time we get telemetry on our GEO, just like we had on our SEO, without having to pay for it.
Lettertrace is super easy to use. Like SO easy. Why? Cause it's got an amazing CLI. Just install it, give Claude Code or Codex access, and your coding agent will go to town. It'll add the topics your buyers actually ask about ("best CRM for startups"). It'll generate realistic prompt variations and run them against Claude, ChatGPT, Gemini, and other major LLMs. It'll track visibility, share of voice, prominence, and sentiment.
npm install lettertrace. claude code. prompt. That's it. Or, if you're non-technical, sign-up traditionally.
And it's actually open source. Not open core, none of those gimmicks. A clean MIT license. Bring your own key. You pay the model providers directly, no markup on top. You'll spend ... maybe $3? If you're just paying to measure AI search, you're getting ripped off and we're putting an end to that.
Three things I'd genuinely like feedback on. First, which answer engines matter enough to add next. Second, whether the generated prompt variations read like questions real people ask, because that's the piece I'm least sure about. Third, did the video effectively explain our purpose as a company?
Congratulations! It’s so nice that it’s open source:) Are you planning to include European models like Mistral ?
How accurate the visibility and the sentiment tracking is compared with the paid tools SEMrush, Profound etc?
Incredible team with deep domain expertise here! Have already enjoyed using their product
Congratulations on the launch @pregasen ! The SEO community needs more such open source and free to use products (like openSEO). Love this and thanks for launching (Profound made a hole in my pocket!)
Ooh, love love love that this is dev-first and oss! Some insight on what you asked - "which answer engines matter enough to add next" - you've hit the main ones we track at Progress, but Grok could be good and for certain niches also Meta AI
Would love to have a single docker run command so I can test it on my own infra in one click. (The current github repo doesnt have the Dockerfile / image either.)
Anyway Thanks for building it, love opensource.
Congrats on the Lettertrace launch, Mathew. The open-source + BYOK framing is very clean, and I loved that the website scan produces editable questions before the first run.
One launch-day thought from trying it: when a first run returns 0%, a new user needs one obvious next move. Is it prompts, competitors, model coverage, or simply a brand that is not yet visible? Turning that zero into a small diagnosis could make the first run feel much more actionable.
Following this closely since I track something similar for my own site. One methodology question that would actually change how I read the numbers: how do you tell the difference between a page getting pulled in as a citation or source versus the AI actually naming the brand in the answer text itself? I have watched my own citation count jump sharply on one engine in a single day while actual brand mention count stayed flat at zero the whole time, so those two clearly do not move together for me. Curious whether you track them as separate metrics or treat citation as a proxy for visibility.
Congrats! Tracking how you show up inside LLM chats is quickly becoming as important as ranking on Google was, and most people have zero visibility into that. Respect for making it open source.
I really like the idea of making AI search visibility more accessible, especially with the open-source and BYOK approach.
The fact that there are no paid tiers or extra markup is a refreshing change, and the CLI sounds great for developers who want to get started quickly.
Congrats on the launch! 🎉
This is cool! There are so many metrics out there used to measure growth or market penetration, this will be helpful in filling the AI marketing analytics gap
I am so tired of share of voice tools charging money just for me to see if they work. I love that this is BYOK. I dont know why somwone didnt do this sooner. Kudos to the Letter Company. Appreciate that the video explains the business model too. Super smart
Congrats, Matthew! This feels like one of those tools you don’t realize you needed until you see it. Curious to see how Lettertrace changes the way teams track AI visibility. 🚀
About Lettertrace on Product Hunt
“Track your AI visibility for free (using your own API keys!)”
Lettertrace launched on Product Hunt on August 12th, 2026 and earned 241 upvotes and 45 comments, earning #2 Product of the Day. Lettertrace measures how often Claude, ChatGPT, and Gemini mention your company. But there's a catch: it's free, developer-first, bring-your-own-key, and open source.
Lettertrace was featured in Open Source (68.7k followers), Analytics (173.2k followers), Marketing (467k followers) and GitHub (41.4k followers) on Product Hunt. Together, these topics include over 136.1k products, making this a competitive space to launch in.
Who hunted Lettertrace?
Lettertrace was hunted by fmerian. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how Lettertrace stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
fmerian
Hey Product Hunt!
Mathew here. I'm the founder of The Letter Company.
Today, we're debuting one of my favorite things that we've ever built. You've likely heard of AEO. Or GEO. Or AI Search. It's a popular space rife with tools. But there's been a big problem: it's pay-to-play. Even to find out how you're doing on AI Search, you need to fork over something crazy like $250/mo.
And I beg.... for what? AI search is effectively measured by a crafty cron job that orchestrates a bunch of model provider calls.
No more $250/mo fees. Now, it's free. Lettertrace is a BYOK telemetry tool for measuring how you're doing on AI search. It's open source. MIT license. Free even on our hosted version. There are no paid tiers. None. Nada. You'll never put down a credit card. We're moving beyond that. It's time we get telemetry on our GEO, just like we had on our SEO, without having to pay for it.
Lettertrace is super easy to use. Like SO easy. Why? Cause it's got an amazing CLI. Just install it, give Claude Code or Codex access, and your coding agent will go to town. It'll add the topics your buyers actually ask about ("best CRM for startups"). It'll generate realistic prompt variations and run them against Claude, ChatGPT, Gemini, and other major LLMs. It'll track visibility, share of voice, prominence, and sentiment.
npm install lettertrace. claude code. prompt. That's it. Or, if you're non-technical, sign-up traditionally.
And it's actually open source. Not open core, none of those gimmicks. A clean MIT license. Bring your own key. You pay the model providers directly, no markup on top. You'll spend ... maybe $3? If you're just paying to measure AI search, you're getting ripped off and we're putting an end to that.
Three things I'd genuinely like feedback on. First, which answer engines matter enough to add next. Second, whether the generated prompt variations read like questions real people ask, because that's the piece I'm least sure about. Third, did the video effectively explain our purpose as a company?
Code: github.com/letterstory/lettertrace