Shipped: REX Guard — Verifiable Controls for AI Agents

We’re a small engineering team in Brazil building REX Guard — Auditable Authority for AI-Initiated Actions at FoundLab.

We’re working on a problem we believe deserves more attention: when an AI agent initiates a financial operation, how do we verify that it was actually authorized, executed within its permitted boundaries, and independently auditable?

REX Guard is our attempt to address this at the infrastructure level.

Our architecture separates AI reasoning from execution authority, applies deterministic policies, and defines how cryptographically verifiable evidence should be produced for critical decisions and their outcomes.

We’ve made our reference architecture public because we believe meaningful trust starts with technical scrutiny, not marketing claims.

What we’ve built so far

Alongside the architecture, we’ve developed an interactive banking demonstration using Google Cloud, Vertex AI, and Google Sign-In. It illustrates AI-assisted financial workflows, consent management, authorization controls, and auditability.

Important clarification: Our demonstration uses Bradesco’s name and visual identity solely as an illustrative banking scenario. It is an independent FoundLab technical demonstration, not an official Bradesco product, deployment, partnership, endorsement, or representation of the bank’s actual systems. All demonstrated banking scenarios are intended for evaluation purposes.

Where we are now

We’re preparing for more demanding technical evaluations and potential pilots involving Tier 1 financial institutions.

We know that a working demonstration and a well-documented architecture are not the same as production validation.

That’s exactly why we’re here.

We’re looking for people who operate real systems on Google Cloud.

If you work with GCP infrastructure, financial services, payments, IAM, cybersecurity, or AI agents, we’d genuinely appreciate your perspective.

We’re especially interested in:

• Engineers willing to review and challenge our architecture.
• Teams open to testing controlled scenarios or exploring a small pilot.
• Feedback on authorization boundaries, latency, integration complexity, failure handling, and audit evidence.
• Design partners who understand the realities of regulated production environments.

We’re not looking for compliments or trying to claim we’ve solved everything.

We’re looking for honest conversations, difficult questions, and opportunities to learn from people who deal with these challenges every day.

Public architecture:
github.com/irelia0nerf/rex-guard-architecture

Interactive banking demonstration (Google Sign-In):
bradesco-rex-guard.web.app/login/

If you’re working on something similar, or see a flaw in our approach, I’d genuinely love to hear from you.

Alex Bolson
Founder & Chief Architect, FoundLab

Don’t trust. Verify.