Show HN: Self-hosted monitoring for AI recommendations (MIT License)
Lettertrace is a free, open-source, self-hosted tool that measures how often AI assistants like Claude, ChatGPT, and Gemini mention your brand. It uses your own API keys, generates prompt variations, tracks share of voice and sentiment over time, and benchmarks competitors.
Lettertrace: Monitor how AI talks about your brand
open-source · bring-your-own-key
Track your AI visibility, for free.
Lettertrace measures how often Claude, ChatGPT, and Gemini mention your company. But there's a catch: it's free end-to-end, developer-first, and open source.
Start monitoring: it's free
works with ChatGPT, Claude & Gemini · self-host in minutes
lettertrace · monitor
$ lettertrace run --project acme
› querying claude-opus-4-8 across 24 prompts…
✓ acme mentioned in 15 / 24 answers
share of voice ████████░░░░░░░░ 41%
sentiment +0.34 positive
top competitor notion · 28%
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how it works
From a topic to a trend line, automatically.
01
Track your topics
Add the subjects your buyers ask about, “best CRM for startups”, “email tools for agencies”.
02
Auto-generate variations
Lettertrace writes the real questions people put to AI assistants, so you monitor how they’re actually answered.
03
Trends over time
Every run is a datapoint. Watch visibility, prominence, and sentiment move week over week.
04
Benchmark competitors
Ingest rival brands and see your share of voice, who the models recommend, and how often.
the numbers that matter
A data-rich visibility report.
Lettertrace turns raw AI answers into the metrics AEO/GEO teams track: visibility, share of voice, prominence, and sentiment, per topic, per model, over time.
Brand visibility
62%
Share of voice
41%
Sentiment
+0.34
Competitors
5
sample answer · claude
“For fast-growing startups, a few tools stand out. Acme is a strong pick for teams that want automation without losing their brand voice, while Notion and Linear are popular for docs and issue tracking…”
Acme
41%
Notion
28%
Linear
19%
Others
12%
features
Everything you need to diagnose AI mentions.
Bring your own key
Use your own Anthropic, OpenAI & Google keys. They’re encrypted at rest and never leave your infrastructure.
Multi-model
Monitor Claude, ChatGPT, Gemini, and Google AI Overviews side by side. Add more answer engines as they matter.
Variation generation
Turn one topic into dozens of natural prompts automatically, no manual prompt-writing.
Sentiment & recommendations
Know not just if you appear, but whether the answer speaks well of you, and recommends you.
Share of voice
See exactly how often you win the answer versus each competitor you track.
Scheduled monitoring
Run daily or weekly on autopilot and build a trend line you can act on.
open source
Yours to run, inspect, and extend.
MIT licensed, fork it, self-host it, make it yours.
Bring your own keys. No usage markup, no middleman.
Your data lives in your own Supabase, no vendor lock-in.
self-host
$ git clone lettertrace && cd lettertrace
$ npm install
$ cp .env.example .env.local
add Supabase URL + keys
$ npm run dev
→ http://localhost:3000
Find out what AI says about you.
Set up your brand, add a key, and run your first monitor in minutes.
Start monitoring, free