Show HN Daily Selection (2025-04-29)
- I built a hardware processor that runs Python
- A pure WebGL image editor with filters, crop and perspective correction
- Sim Studio – Open-Source Agent Workflow GUI
- Web-eval-agent – Let the coding agent debug itself
- Heart Rate Zones Plus – The first iOS app I ever developed
- Autarkie – Instant grammar fuzzing using Rust macros
- Infrabase – Prompt-Ops for AWS
- ProKZee – An Open-Source Network Security Tool Written in Go
- I made a web-based, free alternative to Screen Studio
- Zotero-MCP – Connect Your Research Library with Your AI Assistant
- NanoAgent, zero-dependency 1k-LOC AI-agent runtime
- Trending Topics on Bluesky via Semantic Clustering
- Proventra – Open-source prompt injection security for AI agents
- HyperStandard – Fast. Interactive. Web Interface.
- I just launched Frames, a note app for Analog Photographers
- A tool for building OCR business solutions
- Rust-loguru – A flexible Rust logging library like Python's Loguru
- Mutube – CLI tool to find out if a YouTube video is a relative outlier
I built a hardware processor that runs Python [Developer Tools]
798 points, 219 comments
PyXL is a hardware processor that directly executes Python programs by compiling them into a custom assembly instruction set, bypassing traditional interpreters or VMs.
- Compiles Python → CPython Bytecode → Custom hardware instruction set
- Achieves 480ns GPIO round-trip toggle (vs. 14-25µs on MicroPython)
- Stack-based, fully pipelined design with dynamic typing support
- Independently developed toolchain (compiler, linker, codegen) and hardware
- Benchmarked at 100MHz (faster than MicroPython at 168MHz)
- Full technical details to be presented at PyCon 2025
Discussion Link, Original Link
A pure WebGL image editor with filters, crop and perspective correction [Image]
138 points, 37 comments
A pure WebGL-based open-source image editor with filters, crop, and perspective correction.
- Built entirely with JavaScript and WebGL
- Offers effects, filters, and cropping tools
- Includes perspective correction functionality
- Open-source alternative to closed-source editors
- Available for testing and contribution on GitHub
Discussion Link, Original Link
Sim Studio – Open-Source Agent Workflow GUI [Developer Tools]
111 points, 36 comments
Sim Studio is an open-source drag-and-drop GUI for designing and managing multi-agent workflows as executable directed graphs.
- Open-source and Apache 2.0 licensed
- Visual workflow design with agent blocks, tools, and structured output
- Supports hosted and local models (via Ollama)
- Conditional logic, loops, branching, and LLM-based routing
- Executable workflows with simulation for testing changes
- Deployable as APIs, scheduled jobs, or webhook-triggered processes
- Built-in observability with logs, traces, and performance comparisons
- Pre-built integrations for faster development
- Use cases include research agents, chatbots, and automation workflows
Discussion Link, Original Link
Web-eval-agent – Let the coding agent debug itself [Developer Tools]
58 points, 9 comments
A tool that enables AI-assisted coding agents to debug web apps by testing changes in a browser and evaluating results automatically.
- Integrates with IDEs (Cursor/Windsurf/Cline/Continue) to test UI flows and API responses
- Uses Playwright-powered browser agent to simulate user actions and capture logs
- Reduces latency by proxying Claude calls with Gemini Flash 2.0 (~3s per step)
- Filters and caps logs to stay within context limits
- Generates detailed evaluation reports with console/network events and UX feedback
- Supports macOS/Linux (Windows manual install available)
- Plans to add OAuth handling, browser state management, and automated test creation
Discussion Link, Original Link
Heart Rate Zones Plus – The first iOS app I ever developed [Health]
50 points, 29 comments
Heart Rate Zones Plus is the developer's first iOS app for tracking heart rate zones.
- Tracks heart rate zones
- Developer's first iOS app
Discussion Link, Original Link
Autarkie – Instant grammar fuzzing using Rust macros [Developer Tools]
31 points, 4 comments
Instant grammar fuzzing using Rust macros.
- Uses Rust macros for grammar fuzzing
- Provides instant feedback
- Designed for quick testing and debugging
Discussion Link, Original Link
Infrabase – Prompt-Ops for AWS [Developer Tools]
3 points, 0 comments
Infrabase is an LLM-powered tool for managing AWS infrastructure via prompts, offering faster and more intuitive operations than the AWS console.
- Uses AI to generate AWS SDK code for infrastructure management
- Replaces manual AWS console navigation with prompt-based commands
- Supports multi-step operations and IAM role management
- Currently focuses on AWS but plans to expand to other tools like Datadog and GitHub
- Includes basic auth but lacks advanced validation and approval workflows
- Potential future features include Terraform/OpenTofu export and OIDC integration
Discussion Link, Original Link
ProKZee – An Open-Source Network Security Tool Written in Go [Developer Tools]
5 points, 0 comments
ProKZee is an open-source network security tool for intercepting and modifying HTTP/S traffic, built with Go and React.
- Free and open-source
- Intercepts, inspects, and modifies HTTP/S traffic
- Fast native UI with modern UX
- Comparable to Burp Suite, OWASP ZAP, and Caido
- Built with Go and React using Wails framework
Discussion Link, Original Link
I made a web-based, free alternative to Screen Studio [Video]
422 points, 104 comments
Web-based, free alternative to Screen Studio for screen recording.
- Free to use
- Web-based platform
- Alternative to Screen Studio
Discussion Link, Original Link
Zotero-MCP – Connect Your Research Library with Your AI Assistant [Research]
3 points, 0 comments
Zotero-MCP connects your Zotero research library with AI assistants, enabling LLMs to access your papers, notes, and annotations.
- Integrates Zotero with LLMs via MCP client
- Supports both local and cloud libraries
- Allows AI to read collected papers, notes, and annotations
- Over 1.2k calls on smithery
Discussion Link, Original Link
NanoAgent, zero-dependency 1k-LOC AI-agent runtime [Developer Tools]
5 points, 0 comments
NanoAgent is a lightweight AI-agent runtime with zero dependencies and only 1k lines of code.
- Zero-dependency
- Lightweight (1k LOC)
- AI-agent runtime
Discussion Link, Original Link
Trending Topics on Bluesky via Semantic Clustering [Research]
5 points, 0 comments
Bluesky trending topics identified via semantic clustering from the firehose data.
- Ingests Bluesky firehose data
- Uses custom models for semantic clustering
- Runs on a single GPU
- Provides discussion volume breakdown by topic
- Accessible at dazzle.fm/stats
Discussion Link, Original Link
Proventra – Open-source prompt injection security for AI agents [Developer Tools]
3 points, 0 comments
Open-source security tool to protect AI agents from prompt injection attacks.
- Focuses on securing AI agents interacting with external content like web pages and documents
- Addresses limitations of existing defenses that may reject valuable content
- Aims to provide robust protection against growing prompt injection threats
Discussion Link, Original Link
HyperStandard – Fast. Interactive. Web Interface. [Developer Tools]
5 points, 2 comments
HyperStandard is a fast and interactive web interface.
- Fast performance
- Interactive user experience
Discussion Link, Original Link
I just launched Frames, a note app for Analog Photographers [Productivity]
5 points, 1 comments
A note-taking app for analog photographers to log and embed shooting details into digital scans.
- Logs camera, lens, film stock, exposure settings, and notes
- Embeds metadata into scanned JPEGs
- iPhone app for field notes, Mac app for attaching metadata
- No cloud storage, all data stays local
- Free iPhone app, Mac app offers 7-day trial
- Designed for 35mm, medium format, and large format film photographers
Discussion Link, Original Link
A tool for building OCR business solutions [Developer Tools]
3 points, 0 comments
A simple OCR tool designed as a framework for developers to build custom OCR solutions.
- Framework for building custom OCR solutions
- Developer-friendly tool
- Simple and adaptable for various business needs
Discussion Link, Original Link
Rust-loguru – A flexible Rust logging library like Python's Loguru [Developer Tools]
5 points, 4 comments
A high-performance Rust logging library inspired by Python's Loguru, offering an intuitive API and advanced features.
- Outperforms Rust's standard log crate by 50-80% in benchmarks
- Supports multiple log levels and an extensible handler system
- Features efficient file rotation with better performance than alternatives like log4rs
- Includes error handling utilities and context helpers
Discussion Link, Original Link
Mutube – CLI tool to find out if a YouTube video is a relative outlier [Developer Tools]
6 points, 1 comments
CLI tool to identify YouTube videos that are statistical outliers.
- Detects relative outliers in YouTube videos
- Command-line interface for easy use