Agents get eyes, hands, and a reverse-engineering kit
Welcome to the first Builders Feed. Every day: what real builders shipped, why it matters, and what you could build next.
Shipped
1. Big Arrow on the Screen: agents that point at things
Let your AI agents paint big arrows, boxes, and text directly on your screen. 400+ points on Show HN.
Why it matters: "Show, don't tell" for agents. A visual pointer layer makes agent guidance far easier to follow than a wall of chat text.
github.com/franzenzenhofer/big-arrow-on-the-screen · HN discussion
2. rea: reverse engineer anything with agents
An agent toolkit for reverse engineering, from app behavior down to native binaries. It picked up ~25,000 stars in a day on GitHub trending.
Why it matters: Reverse engineering is a skill-gated field, and agents are collapsing that gate fast. Expect a wave of interoperability tools built on top of it.
github.com/morluto/rea
3. Quake ported to safe Rust, playable in the browser
A full port of Quake to safe Rust that runs in your browser.
Why it matters: A real-world proof that large C codebases can be moved to memory-safe Rust and shipped to the web, not just toy demos.
quake-srp.pages.dev · HN discussion
4. BetterWispr: free, open-source dictation for Mac
An open-source alternative to paid voice-dictation apps.
Why it matters: Voice is becoming the default way to prompt agents. Local, free dictation removes both the subscription and the privacy objection.
betterwispr.com · HN discussion
5. Pinrail: a desktop inbox where coding agents wait for your review
Coding agents queue their work in a desktop inbox until you approve it.
Why it matters: As people run several agents in parallel, the bottleneck is human review. Tools that manage the review queue are a new product category.
github.com/forgeplane/pinrail · HN discussion
6. Rgpu: a PyTorch device whose tensors live on a remote GPU
Use a remote GPU as if it were a local PyTorch device.
Why it matters: Develop on a laptop and compute on a rented GPU without rewriting code. A neat bit of infra for anyone without local CUDA.
github.com/ymcrcat/rgpu · HN discussion
7. God's Eye View: a spy satellite simulator with real data
Live open-source spatial intelligence on a photorealistic 3D globe, in the browser.
Why it matters: Shows how far you can get by combining open geospatial data with modern 3D web rendering, solo.
github.com/bilawalsidhu/gods-eye-view
Build this
Idea 1: Agent Inbox for teams
Pinrail and Big Arrow point the same way: humans need better surfaces for overseeing agents. Build a shared, web-based review queue where every agent run (coding, ops, research) lands as a card with diff, transcript, and one-click approve/reject, plus Slack and mobile notifications. Start with Claude Code and Codex hooks.
Idea 2: "Port it to Rust" agent benchmark
Quake in safe Rust shows ports are now feasible. Build an open benchmark plus a hosted service that takes a small C library, runs an agent to port it to safe Rust, and scores the result on tests passed, unsafe blocks remaining, and performance. Publish a leaderboard.
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