Scattered rules
Resolutions, circulars and normative instructions sit in separate documents, with no search that connects them. Finding the right answer takes far too long.
Regulus
Regulus is an AI assistant that answers regulatory questions based on official documents from the Central Bank of Brazil and Open Finance Brasil, and shows which document each answer comes from. It runs on WhatsApp, with no sign-up.
What is the R$ transaction limit for JSR?
Copy questionRegulus
There used to be a R$ 500 daily cap on the Redirect-free Journey (JSR). The IN BCB No. 746 , from June 2026, removed that cap: the limit is now set by the user. The rule applies since Oct 1, 2026. See the current version of IN BCB No. 512 .
The problem
Anyone running Pix or Open Finance regularly has to answer "what does the regulation say about this?". Today that answer means reading long documents or waiting for legal.
Resolutions, circulars and normative instructions sit in separate documents, with no search that connects them. Finding the right answer takes far too long.
The Central Bank updates the regulatory framework often. A rule from six months ago may have been amended or revoked, and keeping up is a fixed cost for the team.
Assistants like ChatGPT cite articles that don't exist and mix rules from different jurisdictions. In compliance, a wrong answer costs more than no answer.
The solution
Regulus answers based on 7,664 documents on Open Finance and Pix, from the Central Bank and Open Finance Brasil: resolutions, circulars, normative instructions and technical documents. The knowledge base is updated every day overnight and audited by hand by our team. Each answer points to its source document.
Look up a specific rule without opening dozens of PDFs. For fintechs without a legal team dedicated to banking regulation, Regulus is the first filter before final validation.
Example question
What are the requirements for mandatory participation in Open Finance?
CopyKnow what the regulation allows before designing the feature, and set the scope without waiting for legal to get back to you.
Example question
Which payment data can the initiator access via Open Finance?
CopyClear up questions about mandatory fields, formats and deadlines of regulated APIs during implementation.
Example question
What is the maximum response time for a consent request?
CopyHow it works
Start from the link. No sign-up and no new app.
Write in natural language. You can cite the article or resolution, or just describe your company's scenario.
Regulus answers and points to the resolution or circular it came from, so you can check the official document. You get up to 50 free questions a day.
Cumbuca is an institution regulated by the Central Bank and a direct participant in Open Finance. Regulus came from a need of our own engineering team: finding the right rule quickly, with the source at hand.
We opened the tool to anyone who wants to enter the ecosystem the right way. Regulus does for compliance what the Playground does for developers: it gives a reliable starting point.
Every document in the base went through a manual audit. The scope stays limited to Open Finance and Pix because we'd rather answer well than answer everything.
Our team applies these rules every day in the infrastructure it runs. The curation comes from people who implement, not just read.
Up to 50 free questions a day, with the source of each answer, no sign-up.
Connect your ChatGPT/Claude account to your bank account. Work with your financial data with the security of Open Finance, no Cumbuca account needed.
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Learn moreOne place to monitor the whole ecosystem: the status of banks, the PCM, the MQD and the SCR, updated throughout the day.
Learn moreOpen source, hands-on documentation written by people who implement. The quick-start guide the ecosystem needed, built in partnership with Juspay.
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