submilli/submilli-runtime is a Rust runtime that runs TypeScript code written by agents inside an isolated WebAssembly environment. The latest release recorded in the repository is v0.4.1. The provided information contains nothing about what changed in this version, so the specific changes cannot be confirmed.
Instead of pre-screening the source, this runtime checks permissions immediately before external calls. When a package author declares a per-task semantic language in a Blueprint, the runtime decides whether to allow the call. The README example splits refund caps into $500 for platinum customers and $100 for everyone else. In the demo, an $18 shipping replacement passes, while a $42 replacement stays blocked until the cap is raised from $25 to $50. The key point is that the permission boundary is enforced in the runtime rather than in the model prompt. According to the project description, node:http and node:fs were removed and a dedicated runtime was built from scratch; the compiler, runtime, command-line tool, and server are written in Rust. The license is Apache-2.0.
The repository also contains an example harness and skill documentation for coding assistants. However, no quantitative performance benchmarks are presented. So while the design of enforcing semantic permissions at execution time can be confirmed, it is difficult to compare its performance with other runtimes on the basis of evidence.