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@mathewpregasen announced Lettertrace (public launch 2026-08-04), a 100% FREE…

2026-08-04 · 19:03 UTC ·@mathewpregasen ·1 min read

Brief

Author @mathewpregasen launched Lettertrace (announced 2026-08-04), an MIT-licensed, open-source CLI that tracks how often a brand appears in AI search across popular LLMs. It works with Anthropic, OpenAI, Google APIs or router keys (Merge, Concentrate AI, OpenRouter), targets coding agents (Claude Code, Codex, Cursor), and exposes prompt telemetry via the Lettertrace app or elsewhere.

Why it matters

@mathewpregasen announced Lettertrace (public launch 2026-08-04), a 100% FREE ("Not freemium. FREE."), open-source CLI tool licensed MIT that tracks brand/AI visibility on popular LLMs and AI search.

Key details

  • Lettertrace accepts Anthropic, OpenAI, and Google API keys (or a single model-router key like Merge, Concentrate AI, or OpenRouter), is built natively for coding agents (Claude Code, Codex, Cursor), and generates prompt telemetry accessible via the Lettertrace app or external endpoints.
  • The project is positioned as a free alternative to paid SaaS for AI visibility—author explicitly invites reuse: "Steal it, copy it, sell it, build on it."
Source evidence

I am THRILLED to announce the launch of Lettertrace. Lettertrace tracks your AI visibility on popular LLMs ... for free.

You heard that right. Free. Not freemium. FREE. And the best part? It's open source and built on a CLI.

We have long believed that companies should be able to track their brand visibility without having to buy another SaaS solution.

Google Search Console is free. Why isn't AI visibility?

So we changed that.

Just provide your Anthropic, OpenAI, and Google API keys (or, even better, use a single model router key like Merge, Concentrate AI, or OpenRouter). That's it. It'll track how often your brand shows up in AI search.

It's built for coding agents. Natively. Just install our CLI. Then tell Claude Code, Codex, or Cursor. Using your existing company context, the agent will build out prompt telemetry that you can access on the Lettertrace app or literally anywhere else.

It's open source. 100% free (have I mentioned, it's free). MIT license. Steal it, copy it, sell it, build on it. It's entirely up to you.

You might be wondering why we're doing this. Is it out of sheer benevolence? Maybe a little. But this video should clear that up.

Video