Show HN Daily Selection (2025-08-07)

• Kitten TTS – 25MB CPU-Only, Open-Source TTS Model
• Sinkzone DNS – Forwarder that blocks everything except your allowlist
• An open-source e-book reader for conversational reading with an LLM
• CSV Mail Sender – Send personalized email campaigns from a CSV
• When is the next Caltrain? (minimal webapp)
• Chilli – A lightweight microframework for CLIs in Zig
• Tool that helps you launch your startup 10x cheaper and 1,000x faster
• Indicatix – Crypto Market Analysis and Trading Signals
• I open-sourced my framework for debugging sourdough
• TypeScript YAML Plugin – Typed .yaml imports with autocomplete
• Principles of Building AI Agents book [pdf]
• PyJig – an open-source digital jigsaw puzzle factory
• HMPL – Small Template Language for Rendering UI from Server to Client
• Text Symbols
• I built a simple, free sit/stand timer to fix my bad desk habits
• Open-source DIY NAS with GUI and aluminum enclosure
• YouTube to NotebookLM – Send YouTube channels to chat with content
• Twitter Viewer – View & Download Tweets and Media Without an Account

Kitten TTS – 25MB CPU-Only, Open-Source TTS Model [Audio]

751 points, 316 comments

Kitten TTS is a lightweight, open-source text-to-speech model under 25MB designed for on-device use without requiring a GPU.

• Only 25MB in size with 15M parameters
• Supports English TTS with 8 voices (4 male, 4 female)
• Runs on low-power devices like Raspberry Pi, smartphones, and browsers
• Uses int8 + fp16 quantization and ONNX for efficient runtime
• Early preview with future updates planned
• Designed for edge devices to avoid cloud costs and GPU dependency

Discussion Link, Original Link

Sinkzone DNS – Forwarder that blocks everything except your allowlist [Developer Tools]

67 points, 37 comments

DNS forwarder that blocks all internet traffic except explicitly allowlisted domains.

• Blocks everything by default (NXDOMAIN) unless explicitly allowed
• Two modes: Monitor (logs domains) and Focus (blocks non-allowlisted)
• Open-source, written in Go, runs on macOS, Linux, and Windows
• Similar to Pi-hole but focused on allowlist-only browsing

Discussion Link, Original Link

An open-source e-book reader for conversational reading with an LLM [Education]

69 points, 57 comments

An open-source e-book reader with AI integration for interactive and contextual reading.

• Context-aware AI chat for instant answers about the current page/chapter
• AI podcast generation using Google Cloud TTS
• Multi-layer memory system (short-term, mid-term, long-term) for continuity
• Smart annotations with a 5-color highlighting system
• Supports multiple LLMs and languages (EN/JA/ZH)
• Built as a fork of Flow epub reader with added LLM and vector database integration

Discussion Link, Original Link

CSV Mail Sender – Send personalized email campaigns from a CSV [Marketing]

3 points, 0 comments

Send personalized email campaigns from a CSV file.

• Uses CSV files for email campaigns
• Personalizes emails based on CSV data
• Simple and efficient email sending tool

Discussion Link, Original Link

When is the next Caltrain? (minimal webapp) [Travel]

32 points, 25 comments

A minimalist webapp that quickly shows the time until the next Caltrain departure based on the user's location.

• Displays time until next train for simplicity
• Automatically detects direction (southbound from SF, otherwise northbound)
• Designed to be faster and more straightforward than existing options

Discussion Link, Original Link

Chilli – A lightweight microframework for CLIs in Zig [Developer Tools]

5 points, 0 comments

Chilli is a lightweight microframework for building CLI applications in Zig.

• Declarative API for nested commands, flags, and positional arguments
• Type-safe parsing from command line and environment variables
• Auto-generated --help and --version output
• Supports command aliases and persistent flags

Discussion Link

Tool that helps you launch your startup 10x cheaper and 1,000x faster [Business]

3 points, 1 comments

Launch your startup 10x cheaper and 1,000x faster with this tool.

• Cost-effective solution for startups
• Accelerates launch process significantly

Discussion Link, Original Link

Indicatix – Crypto Market Analysis and Trading Signals [Finance]

3 points, 0 comments

Indicatix provides crypto market analysis and trading signals.

• Crypto market analysis
• Trading signals

Discussion Link, Original Link

I open-sourced my framework for debugging sourdough [Life Assistant]

4 points, 0 comments

Open-sourced framework for debugging sourdough.

• Helps troubleshoot sourdough baking issues
• Provides tools for analyzing fermentation and dough behavior
• Open-source and customizable for different baking setups

Discussion Link, Original Link

TypeScript YAML Plugin – Typed .yaml imports with autocomplete [Developer Tools]

3 points, 0 comments

TypeScript YAML Plugin enables typed imports and autocomplete for YAML files in TypeScript 5.

• Adds native support for importing .yaml and .yml files
• Provides full type inference and autocomplete
• Improves readability by avoiding JSON's escaping requirements
• Open source (MIT) and open to contributions

Discussion Link, Original Link

Principles of Building AI Agents book [pdf] [Education]

4 points, 0 comments

A comprehensive guide on building AI agents, covering LLMs, prompting, workflows, RAG, and more, based on real-world experience and community feedback.

• Covers 34 chapters and 148 pages on AI engineering topics like LLMs, agents, RAG, and deployment
• Includes practical insights from leaked production-grade prompts
• Updated editions reflect rapid advancements (e.g., MCP, image generation)
• Written in Notion, formatted with Vellum, and published via Amazon KDP
• Popular among AI meetups, conferences, and LinkedIn
• Free to download and regularly updated based on community feedback

Discussion Link, Original Link

PyJig – an open-source digital jigsaw puzzle factory [Image]

3 points, 0 comments

Open-source tool PyJig generates digital jigsaw puzzle cuts and full sets from any input image.

• Creates jigsaw puzzle pieces from user-provided images
• Originally part of a shelved puzzle app project
• Recently fixed broken dependencies
• Niche but functional for digital puzzle creation

Discussion Link, Original Link

HMPL – Small Template Language for Rendering UI from Server to Client [Developer Tools]

5 points, 4 comments

HMPL is a lightweight template language designed to replace HTMX and Alpine.js by enabling server-side UI rendering with minimal client-side bundle size.

• Combines EJS and Handlebars syntax for server requests directly in HTML markup
• Uses fetch for requests with JavaScript-based configuration
• Reduces client-side bundle size by moving components to the server
• Mature iteration of an earlier concept, now more refined

Discussion Link, Original Link

Text Symbols [Text]

3 points, 0 comments

A collection of text symbols for easy copying and use.

• Provides a variety of text symbols
• Allows easy copying for quick use

Discussion Link, Original Link

I built a simple, free sit/stand timer to fix my bad desk habits [Health]

5 points, 3 comments

Simple, free sit/stand timer to improve desk habits.

• Helps track sitting and standing intervals
• Designed to fix bad desk habits
• Free to use

Discussion Link, Original Link

Open-source DIY NAS with GUI and aluminum enclosure [Consumer Tech]

3 points, 0 comments

An open-source DIY NAS with a GUI and aluminum enclosure, featuring enhanced storage management and hardware durability.

• GUI for monitoring storage, file navigation, image viewing, and file operations
• Aluminum enclosure with USB-PD power and internal UPS
• 3D-printed internal structure for drive and battery protection
• Open-source design files available on GitHub
• Compatible with Radxa Penta SATA HAT and Raspberry Pi 5
• Sideboard connector board for Raspberry Pi 4/5 (open-source)

Discussion Link, Original Link

YouTube to NotebookLM – Send YouTube channels to chat with content [Productivity]

4 points, 0 comments

A Chrome extension that sends YouTube video notes to NotebookLM in one click.

• Allows sending multiple videos from channels, playlists, or search results at once
• Integrates with NotebookLM for creating or updating notebooks
• Free to use and available for Chrome
• Simplifies the process of transferring YouTube content to NotebookLM

Discussion Link, Original Link

Twitter Viewer – View & Download Tweets and Media Without an Account [Consumer Tech]

5 points, 0 comments

View and download tweets and media without needing a Twitter account.

• No account required
• Download tweets and media
• Simple and accessible interface

Discussion Link, Original Link