Letra da Lei
Building · Pre-launch

Give your AI the letter of the law.

We're building a Brazilian legal context layer. It will plug into Claude (or GPT, or Gemini) so answers come back cited by article, on the tool you already use.

Subscribers on the early list get first access when we launch.

Built for the Claude, GPT and Gemini lawyers already use

  • Claude
  • ChatGPT
  • Gemini

The problem

Your AI doesn't know Brazilian law.

Ask Claude or GPT about Art. 5 of the Brazilian Constitution. The answer comes back confident and often wrong. Without grounding, models hallucinate article numbers, effective dates, and entire case summaries.

Invented citations

An "Art. 47 of the CDC" that doesn't exist. "STJ Summary 312" swapped for another. The text reads right, the reference doesn't.

Locked platforms

Full-stack legal platforms force you out of Claude and into a model someone else picked. Then you wait for them to integrate the next one.

Paying twice

Your Claude subscription keeps running. The legal platform charges you again for the AI baked in, which still hallucinates the article.

claude.ai · sem MCP

> Qual é o prazo de prescrição no CDC?

No Código de Defesa do Consumidor (Lei 8.078/90), o prazo de prescrição é de cinco anos (Art. 27), conforme entendimento consolidado pelo STJ na Súmula 312...

↑ Art. 27 do CDC trata de fato do produto, não de prescrição geral. Súmula 312/STJ não existe.

How it will work

You bring the intelligence. We bring the law.

No new app, no extra login. You keep asking Claude (or GPT, or Gemini) the way you already do. Letra da Lei sits underneath, and the model starts consulting Brazilian law automatically before answering.

01

Connect once

At launch, you'll just add Letra da Lei to Claude Desktop (or your AI client of choice) in under a minute.

02

Ask like you always do

Ask your legal question the way you already would. The model decides when it needs a source and consults Letra da Lei automatically, with no special command.

03

Get article-level citations

Answers will come back with structured citation (Art. X, Law Y, effective date), straight from the official source. Click through to verify.

FAQ

What you're probably wondering.

How are you different from JusBrasil AI?
JusBrasil bundles knowledge, intelligence, and interface into one closed product. We focus on the first part: legal knowledge as a layer that plugs into the AI you already use. You pick the model and the interface, and we handle the law.
Where does the data come from?
Official sources. We start with Planalto.gov.br, indexed at the article level with effective-date metadata. No PDFs, no third-party summaries.
When does it launch?
We're building in public. Join the list and we'll let you know the day it goes live.
Which AI will it work with?
The goal is to work with any frontier model via MCP. We start with Claude. GPT, Gemini, and others come as compatibility evolves.

Launching soon

Be one of the first to give your AI the letter of the law.

Join the list. We'll let you know the day it launches, with early access for everyone who signed up first.

No spam. Leave any time.