Pydantic's Monty hits v1.0.0 and drops the experimental label on its Rust Python sandbox.

v1.0.0, published September 25 at 8,323 stars, adds percent formatting, format(), CWD support, eager awaits, long-int handling across pow/round/math, and Python 3.14t wheels. The docs say filesystem, environment and network don't exist inside the interpreter unless you pass in functions or mounts, and put startup under 1ms from a running pool against about 1,500ms for a sandbox service. For code-mode agents that write Python instead of chaining tool calls, that startup difference changes what's feasible per turn.