Lex

The substrate for software you don't fully trust.

In Lex, effects are part of the type. What a piece of code is allowed to do is checked before it runs and re-checked at runtime — from sandboxing a function an LLM just wrote, up to bounding what a learned policy may do to a robot. Trust by verification, not comprehension.

Alpibru is one founder and agentic AI. The stack below — a language, a runtime, a registry, and production stacks across finance, energy, and robotics — is the demonstration: it is possible because trust here is mechanical (typed effects, tests, tamper-evident attestation), not headcount. This is the new shape of a software company.

Trust by construction

Effects are the contract

A [net] function can't touch the filesystem — the program is rejected at type-check, before it runs.

Capabilities, enforced

lex-os runs code in a sealed box with a granted budget; the supervisor mediates every command and can kill or reprovision.

Tamper-evident by default

Every action is a content-addressed, hash-chained event — an attestation trail you can replay and verify, not just trust.

See it live

The same idea — capability and audit enforced by construction — as two things you can actually go run, not just read about.

The stack

Run it

## install the toolchain (Linux/macOS/Windows binaries)
#   https://github.com/alpibrusl/lex-lang/releases

## a function that declares [net] cannot reach the filesystem:
fn fetch(url :: Str) -> [net] Result[Str, Str] { io.read("/etc/passwd") }
#   rejected at type-check — the effect isn't in the signature.