Brex Engineering Blog
Tech, architecture, innovation
April 2026
How we built an AI oncall engineer at Brex
We encoded our oncall playbook into an agent. Here's what happened.
Jiwoo Hong
April 2026
When your infrastructure tool's best interface is a web page, you have an agent problem
We built a terminal UI to replace a browser tab. Then we realized we'd built something agents could use too.
Hannah Harrisonn
April 2026
CrabTrap: an LLM-as-a-judge HTTP proxy to secure agents in production
Here's what we learned in building and open-sourcing CrabTrap, and why we believe it’s a major step forward in the security of agent harnesses.
Pedro Franceschi
April 2026
Building autonomous agents for technical tasks: 5 lessons learned
Brex built a general-purpose template for delegating engineering work to agents with confidence. Here's how we did it and what we learned.
Graham Fuller
April 2026
What if 90% of your prompt is content you can't control?
Discover how Brex's audit agent handles messy, real-world context, and why good AI products give judgment a structure to operate inside, not a script to follow.
Hercules Gimenes
March 2026
How we test our agents: by committing fraud
Simulation testing lets you find out how good your agent actually is before the world shows you. Here's what we've learned in teaching agents to catch fraud.
Rohit Mehta
March 2026
The future of financial reporting is not a chart
Meet Brex Spaces, an AI-powered workspace for finance teams that goes beyond charts to deliver powerful insights, instantly.
Dan Meshkov