--- title: "Afraid of AI writing bad code? Sphinx forces a test before Git Push, plus a GPU-free tool to test LLM speed: Open Source Weekly" description: "Happily pushing AI-written code but don't actually understand it? Sphinx, an open-source tool trending on Hacker News this week, intercepts you right before your Git push, forcing a code comprehension test to make you a responsible engineer! I'm Mu Yan. In this issue of \"Open Source Weekly,\" besides trying out this foolproof tool, I'll also introduce a cool tech that \"simulates LLM speeds on various GPUs right in your browser.\" Want to know how fast your Mac runs Llama 3? I'll tell you in a moment!" canonical_url: "https://blog.markkulab.net/en/open-source-weekly/open-source-weekly-2026-10-21" author: "Mark Ku" author_url: "https://blog.markkulab.net/en/author/mark-ku" site: "Mark Ku's Tech Notes" date_published: "2026-10-21T02:00:00.000Z" category: "Open Source Weekly Finds" tags: ["open-source", "podcast", "開源工具", "開源", "Sphinx", "Llmspeed", "Esp32sim", "Git", "LLM", "ESP32", "Rust"] language: "en" license: "CC BY 4.0" license_url: "https://creativecommons.org/licenses/by/4.0/" attribution: "when reusing or quoting, credit the author and link back to the original" --- # Afraid of AI writing bad code? Sphinx forces a test before Git Push, plus a GPU-free tool to test LLM speed: Open Source Weekly **2026-10-21** ## Introduction Love using AI to write code and happily pushing it, only to realize you don't actually understand what it does? Sphinx, an open-source tool trending on Hacker News this week, intercepts you right before your Git push, forcing you to take a code comprehension quiz and making you be a responsible engineer! I'm Muyan. In this week's "Open Source Weekly," besides taking this foolproof tool for a spin, I'll also introduce a cutting-edge tool that simulates LLM speeds on various GPUs right in your browser. Want to know how fast your Mac can run Llama 3? I'll tell you in a bit! --- ## This Week's Open Source Picks ### 1. Sphinx: An AI Code Comprehension Quiz Tool Before Git Push - **What it is**: It solves a major pain point for modern engineers: over-relying on AI to write code and blindly pushing it. Once you finish writing code with AI assistance, it inserts a quiz right before your Git push to ensure you actually understand the AI-generated code, rather than blindly submitting a PR. - **Buzz this week**: It gained significant traction on Hacker News with 252 points, sparking 89 comments in a heated debate about "how to maintain code quality in the AI era." - **Key Features**: 1. **Git Hook Interception and Automated Quizzes**: It automatically intercepts your workflow during the Git push phase, reads your commit diff, and uses an LLM to generate a comprehension quiz. 2. **Support for Multiple AI Assistants**: It perfectly supports code generated by mainstream AI coding assistants like Claude Code, Cursor, and Copilot. 3. **Custom LLM Endpoints**: It supports OpenRouter or any OpenAI API-compatible service, eliminating the need for extra paid subscriptions to specific SaaS platforms. 4. **YOLO Escape Hatch**: If you are in a rush to deploy, it supports using `yolo` to quickly bypass the quiz, but every bypass is recorded in the logs for future team audits, leaving a paper trail if you try to slack off. - **Quick Start**: Install it globally and bind it to your Git hooks in your project directory: ```bash npm install -g sphinx-understand sphinx install ``` - **How it compares**: Unlike traditional static analysis tools or automated tests, Sphinx doesn't just check code syntax or logic. Instead, it directly tests the "human developer's" understanding of the code. - **Who it's for**: Perfect for engineers who want to break the habit of "blindly trusting AI," or team leads who want to ensure team members take responsibility for their own code. - **Link**: [Sphinx Official Website](https://sphinx-six-theta.vercel.app/) --- ### 2. Llmspeed: An LLM Execution Speed Simulator in the Browser - **What it is**: Designed for engineers who want to run open-source LLMs locally but struggle with hardware choices. It simulates the actual generation speed of specific models on different GPUs or Mac chips directly in the browser, solving the pain point of buying the wrong hardware and wasting money. - **Buzz this week**: It garnered 329 points on Hacker News, attracting 86 comments. - **Key Features**: 1. **Hardware Speed Simulation**: It simulates the tokens per second (tokens/sec) when running specific open-source models on various mainstream hardware, such as the NVIDIA RTX series and Apple Silicon Macs. 2. **Perceived Speed Visualization**: It simulates Time to First Token (TTFT), allowing users to experience the actual perceived speed of the "typewriter" output. 3. **Community-Backed Data**: The data is based on community-verified benchmarks, and users can submit new hardware data via Pull Requests. - **Quick Start**: You can use the web version directly by opening `llmspeed.dev`. If you want to run it locally, clone the repository and run: ```bash npm install && npm run dev ``` - **How it compares**: Unlike benchmark tables that only provide cold performance numbers (such as LLM-Perf), Llmspeed provides an intuitive simulation of perceived speed by rendering the text stream in real time right in the browser. - **Who it's for**: Ideal for engineers facing decision paralysis over which graphics card or Mac to buy for running local LLMs. - **Link**: [Llmspeed Official Website](https://llmspeed.dev/) --- ### 3. Esp32sim: A Pure Rust Browser-Based ESP32 Instruction-Level Simulator - **What it is**: It allows embedded and IoT developers to simulate ESP32 chips directly in the browser, solving the pain point of not having a physical development board on hand or wanting to quickly validate firmware logic. - **Buzz this week**: It received 206 points on Hacker News (with 46 comments) and currently has 545 stars on GitHub under the MIT license. - **Key Features**: 1. **Dual-Architecture Instruction-Level Simulation**: It supports both Xtensa (ESP32, S3) and RISC-V (C3, C6) architectures. 2. **Full ROM Booting**: It can boot the actual mask ROM, bootloader, and unmodified application images directly in the browser via WebAssembly. 3. **Peripheral and UI Simulation**: It supports simulating Touch-LCD screens, smoothly rendering LVGL UIs with mouse interaction support. - **Quick Start**: You can experience the web version directly by opening `mikroverk.github.io/esp32sim/`. For local execution, you can run it via Rust: ```bash cargo run ``` - **How it compares**: Compared to online simulators like Wokwi, Esp32sim is an open-source, instruction-level simulator written entirely in Rust. It simulates the actual ROM boot process at a lower level and operates completely independent of cloud servers. - **Who it's for**: Perfect for IoT engineers who want to avoid constantly plugging and unplugging USB cables and want to quickly debug ESP32 firmware and UIs in the browser. - **Link**: [Esp32sim GitHub](https://github.com/mikroverk/esp32sim) --- ## Closing Thoughts From foolproof Git quizzes and LLM speed simulations to in-browser chip simulators, this week's tools significantly reduce our development and decision-making costs. I highly recommend everyone give Sphinx a try. After all, forcing yourself to understand AI-written code is the ultimate way to secure your job. See you in next week's "Open Source Weekly"! --- ## About this article and its author Originally published on [Mark Ku's Tech Notes](https://blog.markkulab.net/en/open-source-weekly/open-source-weekly-2026-10-21) License: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) — when reusing or quoting, credit the author and link back to the original ### About the author **[Mark Ku](https://blog.markkulab.net/en/author/mark-ku)** — Software engineer - 10+ years as a software engineer - Built North-American e-commerce and AI SaaS subscription billing ### Free tools built by the author All of these are free to use: - [Free PDF Sign Tool](https://blog.markkulab.net/en/tools/pdf-sign): Online PDF sign tool — draw, type, or upload a signature, then drag, resize, and download. Everything runs in your browser; nothing is uploaded. - [VS Code Refactory](https://blog.markkulab.net/en/tools/refactory): Refactory is a VS Code refactoring extension: 34 actions plus a 37-rule code-smell inspection layer with a Code Health dashboard, across 18 languages, backed by 534 tests. It learns your repo's conventions: where interfaces live, where DI is registered, whether 'use client' belongs. It ranks files by git churn × complexity so you know what to fix first, and hands any smell to the Claude Code already on your machine. Free to use, and your source never leaves your computer. - [DB-Kit Database Manager](https://blog.markkulab.net/en/tools/db-kit): DB-Kit is a lightweight, cross-platform database manager built with Tauri + Rust + React. Manage MySQL, MariaDB, PostgreSQL, SQL Server, Oracle, SQLite, MongoDB, Redis, Kafka, Elasticsearch and RabbitMQ from one consistent interface: passwords encrypted in the OS keychain, SSH tunnels, full CRUD, a visual query builder, stacked multi-statement result sets, cross-connection data transfer, schema & data compare with sync SQL and schema snapshots, Excel / CSV import & export, visualized execution plans, ER diagrams, scheduled backups, SQL stress testing with p50–p99 latency percentiles, a 15-rule SQL review engine, Review & Run (AI review plus per-statement backups and an auto-generated rollback script), Kafka message browsing with monitoring & alerts, an SSH terminal with SFTP / FTP, Docker / Kubernetes, remote desktop (RDP / VNC / RustDesk), file / folder compare, stored procedure integration tests, six UI languages, a built-in AI assistant (a local CLI or any Anthropic / OpenAI-compatible API; natural-language SQL, AI review and tuning advice) and the dbk CLI. Free and open source (MIT), with installers for Windows, macOS and Linux. - [VS Code Super Mermaid](https://blog.markkulab.net/en/tools/super-mermaid): Super Mermaid is a VS Code extension for beautiful Mermaid diagrams out of the box: auto-colored live preview, mouse pan & zoom, high-res PNG / SVG export, 21 templates and multiple themes. Free and open source (MIT). - [React Super Mermaid](https://blog.markkulab.net/en/tools/react-super-mermaid): react-super-mermaid is an open-source React component library: render beautiful Mermaid diagrams with a single , with built-in colorful / sketch themes, pan & zoom, in-diagram search, and high-res SVG / PNG export. Lightweight, SSR-safe, fully typed. Free and open source (MIT). - [Jira / Confluence Super Mermaid](https://blog.markkulab.net/en/tools/jira-super-mermaid): An Atlassian Forge app: write Mermaid syntax directly inside a Jira issue or a Confluence page and get flowcharts, sequence diagrams, state machines and Gantt charts. 11 diagram types, SVG / PNG export, light and dark themes, full CJK support. Runs on Atlassian: your diagrams live in your own site and the app calls no third-party service. Free, coming soon to the Atlassian Marketplace. - [Mermaid Live Preview](https://blog.markkulab.net/en/tools/mermaid-preview): Write Mermaid in your browser, see it render instantly, and share the whole diagram as a single link. No sign-up, nothing uploaded to a server, and mermaid.live share links work as-is. - [React Intl Phone Number](https://blog.markkulab.net/en/tools/react-intl-phone-number): react-intl-phone-number is an open-source React component: framework-agnostic and antd-free, with E.164 in/out, a searchable flag / country-code dropdown, configurable validation levels (strict / mobile-strict / loose), themeable CSS, and i18n — phone logic powered by google-libphonenumber. Lightweight and fully typed. Free and open source (MIT). - [Uptime Kuma Cluster](https://blog.markkulab.net/en/tools/uptime-kuma-cluster): Turn single-node Uptime Kuma into a highly available cluster: OpenResty + Lua smart load balancing, shared MariaDB state, health checks and automatic failover, plus cluster-management REST APIs. One Docker Compose command to start. Free and open source (MIT). - [AI Podcast Cut](https://blog.markkulab.net/en/tools/ai-podcast-cut): Drop in a recording and it removes fillers and stutters, levels loudness segment by segment, and sends a second agent to review every cut. Cut points snap to word boundaries and zero crossings, every splice gets a fade, and sentence-end breaths are preserved. Desktop app for Windows, macOS and Linux. MIT licensed; the Windows installer bundles ffmpeg. - [AI Video Cut](https://blog.markkulab.net/en/tools/ai-video-cut): Pick something in your video: type it (face, license plate, phone screen, logo), click points or drag a box, or let Claude Code / Codex pick it. AI Video Cut tracks it frame by frame, then mosaics or blurs it, recolors it, pins stickers and text to it, swaps a screen or poster for your own image or video, or removes it using background that other frames actually captured. Plus sequence editing, local captions and an AI assistant. Free, open-source (MIT) Windows desktop app (macOS / Linux experimental) that runs locally, nothing uploaded. - [open-pos restaurant POS](https://blog.markkulab.net/en/tools/open-pos): One computer and one receipt printer is enough to open the shop. Your data lives on your own disk, no subscription, no lock-in, MIT licensed. Money is integer New Taiwan dollars with tax split by the statutory formula, so sales + tax always equals the total. Printing goes straight over ESC/POS on TCP 9100, with no vendor driver. Tauri + Rust + SQLite desktop app, v1.0 in development. - [.NET e-commerce API template](https://blog.markkulab.net/en/tools/dotnet-ecommerce-api): An e-commerce backend API template built on .NET 10: Controller → Service → Repository layering, Autofac convention-based registration, SqlSugar for MySQL / MariaDB and SQL Server, Redis cache and message queue, Hangfire jobs, JWT auth, and an extensible payment provider module (ECPay, Newebpay). Apache 2.0. - [Open Token Monitor team AI usage](https://blog.markkulab.net/en/tools/open-token-monitor): Collect token usage and equivalent cost from every employee's AI coding tools into a hub you host yourself: PostgreSQL, org roster, dashboards compared by company and department, and a reports API. Electron and Rust/Tauri clients upload every 30 minutes. MIT licensed, one Docker command. - [ai-security-monitor defensive security](https://blog.markkulab.net/en/tools/ai-security-monitor): ai-security-monitor is a single Rust binary for your computers and servers. It finds unusual connections, rates them safe / unknown / suspicious / dangerous against 26 public threat-intel sources, and checks firewalls, open ports, vulnerabilities and 60 hardening rules. Security Hub shows the whole fleet, and Claude Code / Codex explain it in plain words. MIT, free, self-hosted. ### Daily podcasts - [Mark's Tech Insights — Daily AI News](https://blog.markkulab.net/en/category/tech-news): Daily curated AI and tech trends. Catch the latest developments via audio summaries — covering AI applications, software architecture, DevOps, and engineering practice. — RSS: https://blog.markkulab.net/feed.xml - [AI股市蝦聊](https://blog.markkulab.net/en/category/ai-stock-chat): Every trading day, an AI-analyzed take on the Taiwan stock market, delivered as a two-host conversation covering the session and the next-day outlook. — RSS: https://blog.markkulab.net/ai-stock-chat/feed.xml - [開源好物週報](https://blog.markkulab.net/en/category/open-source-weekly): A weekly two-host pick of free open-source tools surfaced from real Hacker News, GitHub, and Reddit buzz — what pain they solve and the fastest way to get started. — RSS: https://blog.markkulab.net/open-source-weekly/feed.xml - [AI 運動週報](https://blog.markkulab.net/en/category/sports-weekly): Two hosts talk NBA, MLB and world sport three times a week — scores, records and the stories behind them, from a Taiwanese fan perspective. — RSS: https://blog.markkulab.net/sports-weekly/feed.xml - [AI 國際新聞快報](https://blog.markkulab.net/en/category/world-news): A daily two-host briefing that makes sense of the past 24 hours in world news — geopolitics, the global economy, conflict and security, disasters and climate — from a Taiwanese perspective, neutral and fully sourced. — RSS: https://blog.markkulab.net/world-news/feed.xml - [地端 AI 實驗室](https://blog.markkulab.net/en/category/local-ai-lab): Twice a week, a two-host look at open-weight models and LoRAs you can actually run on your own machine: what they are for, whether your GPU can handle them, and how they compare — sourced from official model cards. — RSS: https://blog.markkulab.net/local-ai-lab/feed.xml - [AI 行銷週報](https://blog.markkulab.net/en/category/ai-marketing): Every Tuesday, two hosts break down the week in AI for marketing, advertising, SEO/GEO and content marketing: practical, never sponsored, every story sourced. — RSS: https://blog.markkulab.net/ai-marketing/feed.xml - [AI 資安週報](https://blog.markkulab.net/en/category/ai-security): Every Thursday, two hosts cover the week where AI meets cybersecurity: LLM and AI agent vulnerabilities, prompt injection, model supply-chain risks and AI-powered attacks, from a defense-first angle with every story sourced. — RSS: https://blog.markkulab.net/ai-security/feed.xml ### Newsletter [Subscribe to the newsletter](https://blog.markkulab.net/en/subscribe) — Be the first to know about new posts. 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