# Porting a PII tracer byte-exact from Python to TypeScript, so a coding agent cannot leak your secrets

> Source: <https://dev.to/alegrib/porting-a-pii-tracer-byte-exact-from-python-to-typescript-so-a-coding-agent-cannot-leak-your-3mj1>
> Published: 2026-10-29 07:08:12+00:00

My coding agent is good at its job. It is also one `cat .env` away from sending my keys to a vendor. I did not want to trust a prompt for that. I wanted the request itself to be clean, provably, before it leaves.

This is the story of porting a PII tracer from Python to TypeScript - byte-exact - so it could run inside the agent's pipeline instead of next to it.