A library for `exec`ing Python code safely using WASM
Inspired by Simon Willison's blog post that was catalyzed by this HN post: https://news.ycombinator.com/item?id=34598024 wasm_exec is a Wasm-powered, sandboxed implementation of exec() for safely running dynamic Python code There are number of use-cases emerging that require arbitrary code execution, often code that is generated by LLMs (Large Language Models) like ChatGPT. This can enable some really cool functionality - like generative BI or website generation - but also introduce a massive security flaw if implemented via eval() or exec(). This is because arbitrary code can…
A library for `exec`ing Python code safely using WASM launched on June 21, 2023 with 6 votes, #1,856 of 4,655 launches that month and more than 50% of that year's launches. The site was still online in September 2026, 3 years on.
What it does
WASM-powered sandbox implementation of exec() for safely running dynamic Python code - Jflick58/wasm_exec
In the maker’s words, at launch
Inspired by Simon Willison's blog post that was catalyzed by this HN post: https://news.ycombinator.com/item?id=34598024 wasm_exec is a Wasm-powered, sandboxed implementation of exec() for safely running dynamic Python code There are number of use-cases emerging that require arbitrary code execution…
Does a similar job
all alternatives →
WASM runtime for sandboxing Python code2024 · github.com · ▲9A while ago I started experimenting with compiling the Python interpreter to WASM. To build a secure, fast, and lightweight sandbox for code execution — ideal for running LLM-generated Python code.
Jaws – a JavaScript to WASM ahead-of-time compiler2024 · github.com · ▲290I've open sourced a JavaScript to WASM compiler. It's an experimental tool, but given the semantics I already implemented, I'm fairly certain I am able to eventually cover 100% of JavaScript spec. Any ideas, questions or critique welcomed! If you are interested in WASM, especially with new proposals like WASM GC or exception handling, it might be a good source of seeing these features in action - the project has a few thousand lines of hand written WAT so far.
A MCP server to evaluate Python code in WASM VM using RustPython2025 · github.com · ▲41This is a pet project of mine where I build a MCP with WASM plugin system (published to OCI). I added a new plugin today that use Rust, compiled to WebAssembly to run Python code securely.
Sandboxing untrusted code using WebAssemblyFeb 2026 · github.com · ▲76Hi everyone, I built a runtime to isolate untrusted code using wasm sandboxes. Basically, it protects your host system from problems that untrusted code can cause. We’ve had a great discussion about sandboxing in Python lately that elaborates a bit more on the problem [1]. In TypeScript, wasm integration is even more natural thanks to the close proximity between both ecosystems. The core is built in Rust. On top of that, I use WASI 0.2 via wasmtime and the component model, along with custom SDKs that keep things as idiomatic as possible. For example, in Python we have a simple decorator:…
Magentic – Use LLMs as simple Python functions2023 · github.com · ▲283This is a Python package that allows you to write function signatures to define LLM queries. This makes it easy to mix regular code with calls to LLMs, which enables you to use the LLM for its creativity and reasoning while also enforcing structure/logic as necessary. LLM output is parsed for you according to the return type annotation of the function, including complex return types such as streaming an array of structured objects. I built this to show that we can think about using LLMs more fluidly than just chains and chats, i.e. more interchangeably with regular code, and to make it…
- OAObelisk – a WASM-based deterministic workflow engine2025 · obeli.sk · ▲103
A lightweight engine for durable execution / deterministic workflows I built with Rust, wasmtime and the WASM Component Model. Its main use is running reliable, long-running workflows that can automatically resume after failures. Looking for feedback on the approach and potential use cases!
More dev tools this month
the category →

open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.
Dev tools · 27d ago · github.com

Contribute to reladraw/reladraw development by creating an account on GitHub.
Dev tools · 25d ago · github.com
OpenBot▲362Grok Bot alternative: free, local, open-source, multiplayer
Dev tools · 22d ago · openbot.run
Talanoa▲340Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…
Dev tools · 20d ago · talanoa.email
CoreSpeed▲332One MCP for everything your agents need: apps, memory, tools
Dev tools · 27d ago · corespeed.io
Source: Show HN post ↗ · launch text quoted in part
Launched alongside, June 2023
the whole month →
Heya HN, I've been working on a reddit-like platform as my primary side project for the last few years. Doing a (very) soft launch today, mainly because I want to use it to encourage discussion of alternatives. How non.io works: 1. Free to browse, paid to interact. 2. Minimum subscription is $2 (though you can choose more). I take $1 to run the servers, everything left gets split evenly between everything you upvote that month. It's a simple model, but I hope it's a better one than the freemium model we've been relying on for the last few years. Fundamentally I feel like any ad-supported…
Commerce · 2023 · non.io

Typefully 2.0▲931Effortlessly publish on Twitter and LinkedIn, now with AI
Growth · 2023 · typefully.com

SlashPage▲755Create websites in seconds to build your first 1K community
Growth · 2023 · slashpage.com

Easy to use AI-powered, drag-and-drop website, SAAS landing, directory, and blog builder for startups, mobile apps, and SaaS. 100% no code, no design skills needed.
AI · 2023 · unicornplatform.com