Show HN Daily Selection (2025-09-24)

• Kekkai – a simple, fast file integrity monitoring tool in Go
• FlyCode – Recover Stripe payments by automatically using backup cards
• Open-source AI data generator (now hosted)
• SSH-hypervisor – like SSH, but each user gets their own microVM
• Devbox – Containers for clean dev environments
• WindowSill
• Mirrow – TypeScript DSL for animated SVGs with compile-time checks
• Snapdeck – Build slides with open-source LLMs and agent routing
• I build free anonymous chat app
• Handcrafted Kitchen SVG Icons
• Cparse is an LR(1) and LALR(1) parser generator in C

Kekkai – a simple, fast file integrity monitoring tool in Go [Developer Tools]

46 points, 12 comments

Kekkai is a lightweight file integrity monitoring tool in Go that detects unauthorized file changes by comparing content hashes.

• Content-only hashing (ignores timestamps/metadata)
• Symlink protection (detects swaps/changes)
• Secure S3 storage (deploy servers write-only, app servers read-only)
• Single Go binary with minimal dependencies

Discussion Link, Original Link

FlyCode – Recover Stripe payments by automatically using backup cards [Finance]

14 points, 31 comments

FlyCode automatically recovers failed Stripe payments by retrying backup cards, reducing subscription churn.

• Identifies and retries valid backup cards when primary payments fail
• Configurable retry timing and validity rules (e.g., recent card usage)
• No-code Stripe integration, requiring no manual workflows
• Increases recovery rates by 18–30% without raising refunds/chargebacks
• Monitors failed invoices and leverages Stripe’s PaymentMethod API
• Designed for SaaS teams, inspired by enterprise solutions like Microsoft/Amazon

Discussion Link

Open-source AI data generator (now hosted) [Developer Tools]

33 points, 0 comments

An open-source AI dataset generator now available as a hosted service or self-hosted solution.

• Offers both hosted and open-source versions for flexibility
• Supports multi-provider LLM integration via LiteLLM
• Fully open-source code for customization and contributions
• Designed for easy AI dataset generation and experimentation

Discussion Link, Original Link

SSH-hypervisor – like SSH, but each user gets their own microVM [Developer Tools]

6 points, 1 comments

SSH-hypervisor provisions a dedicated microVM for each user upon SSH login, bundled as a single static binary.

• Each SSH login creates an isolated microVM for the user
• Includes kernel, firecracker, SSH server, and networking tools in one binary
• Supports x86_64 and aarch64 architectures
• Features custom progress bars and color animations
• Debugged VM setup, boot, and networking challenges

Discussion Link, Original Link

Devbox – Containers for clean dev environments [Developer Tools]

4 points, 0 comments

Devbox is a lightweight, open-source CLI tool for creating isolated development environments using Docker, keeping code on the host machine while running projects in disposable containers.

• Instant setup with devbox init and devbox shell
• Configurable via JSON (devbox.json) for reproducible setups
• Docker-in-Docker support by default
• Host-friendly editing with containers handling runtime
• Templates for Python, Node.js, Go, and web dev
• Advanced options like port mapping, env vars, and resource limits
• MIT-licensed, Linux-focused (Debian/Ubuntu, WSL2 on Windows)
• Easy installation via curl script

Discussion Link, Original Link

WindowSill [Productivity]

4 points, 0 comments

A universal command bar for Windows 10/11 with AI-powered text assistance and productivity tools.

• AI text assistant for summarizing, rewriting, translating, or fixing grammar without app switching
• Short-term reminders with full-screen notifications
• Clipboard history for quick access to recent copies
• URL & text utilities (shortening, QR code generation)
• Media & meeting controls (playback, Teams mute/unmute)
• Customizable placement and size
• Extensible via SDK for app integrations

Discussion Link, Original Link

Mirrow – TypeScript DSL for animated SVGs with compile-time checks [Developer Tools]

3 points, 2 comments

Mirrow is a TypeScript DSL for creating animated SVGs with compile-time checks and simplified syntax.

• Compile-time checks and attribute validation
• Inline event handling (e.g., on:click, @hover)
• CLI tool for converting .mirrow files to static SVGs or components
• Playground available for quick experimentation
• No JSX or manual CSS required

Discussion Link, Original Link

Snapdeck – Build slides with open-source LLMs and agent routing [Productivity]

7 points, 5 comments

Snapdeck is an AI-powered slide creation tool that uses open-source LLMs and agent routing to generate fully editable slides and charts.

• Routes tasks across multiple open-source and commercial AI models for structured slide generation
• Produces fully editable slides, layouts, visuals, and content via drag-and-drop or natural-language commands
• Supports PDF output with PPTX export coming soon
• Achieved #2 on Product Hunt with ~30% retention among target users
• Considering open-sourcing parts of the orchestration layer

Discussion Link, Original Link

I build free anonymous chat app [ChatBots]

5 points, 4 comments

Anonymous chat app with no registration required.

• Free to use
• No registration required
• Anonymous chatting

Discussion Link, Original Link

Handcrafted Kitchen SVG Icons [Design]

9 points, 4 comments

Handcrafted SVG icons for kitchen-related designs.

• High-quality SVG format
• Kitchen-themed icon set
• Handcrafted design

Discussion Link, Original Link

Cparse is an LR(1) and LALR(1) parser generator in C [Developer Tools]

3 points, 2 comments

Cparse is an LR(1) and LALR(1) parser generator written in C.

• Generates LR(1) and LALR(1) parsers
• Written in C for performance and portability
• Suitable for compiler and interpreter development

Discussion Link, Original Link