Show HN Daily Selection (2025-07-19)

• Molab, a cloud-hosted Marimo notebook workspace
• I built library management app for those who outgrew spreadsheets
• AI File Sorter: Organize Files and Folders with AI (Local LLMs)
• Benchstreet – the stock prediction AI benchmark
• RateMyPrompt – share and rate prompts with auto AI evals
• Mock FedCM Integrations
• Brainfork – Create a personal RAG MCP server in seconds
• Tips for getting great Text2Cypher outputs from LLMs for Graph RAG
• Mark 1.0, a notation that unifies JSON, HTML, JSX, XML, YAML, and more
• Child Affordability Index
• Fluent-state: a new fresh take on local React state
• Self-made web media player without <video> or <audio>
• UML is dead – so I'm building the tool to revive it
• Take – process file lines with a logic-like language

Molab, a cloud-hosted Marimo notebook workspace [Developer Tools]

61 points, 8 comments

Molab is a cloud-hosted workspace for Marimo, an open-source reactive Python notebook, offering modern features for collaborative data workflows.

• Persistent storage powered by Cloudflare R2
• Link sharing for public but undiscoverable notebooks
• Download notebooks as Python scripts or apps
• CLI for uploading local notebooks to the cloud (coming soon)
• Real-time collaboration (coming soon)
• Configurable CPU/GPU resources (coming soon)
• Fast package installation using uv
• Modern tech stack (Pydantic Logfire, Modal for compute)
• Free for reasonable usage, focused on community adoption

Discussion Link, Original Link

I built library management app for those who outgrew spreadsheets [Productivity]

41 points, 27 comments

A personal library management app designed for book enthusiasts who need more than spreadsheets but less complexity than institutional systems.

• Multiple libraries for different locations
• Location tracking for precise shelf placement
• Loan management to track borrowed books
• Custom fields and tags for personalized organization
• Reading progress tracking with dates and ratings
• Modern, clean UI/UX for ease of use
• Beta version available with ongoing improvements

Discussion Link, Original Link

AI File Sorter: Organize Files and Folders with AI (Local LLMs) [Productivity]

3 points, 0 comments

AI-powered tool for organizing files and folders locally using local LLMs.

• Supports local LLMs
• Works across Windows, macOS, and Linux
• Automates file and folder organization

Discussion Link, Original Link

Benchstreet – the stock prediction AI benchmark [Finance]

4 points, 0 comments

AI benchmark for stock predictions.

• Evaluates stock prediction AI models
• Provides comparative performance metrics
• Helps identify top-performing algorithms

Discussion Link, Original Link

RateMyPrompt – share and rate prompts with auto AI evals [Developer Tools]

8 points, 4 comments

A platform for sharing and rating AI prompts with automated evaluations and human feedback.

• Offers 500+ AI-generated prompts using latest model guidelines
• Supports 5 prompt types: full, enhancement, template, system, and chain
• Covers 20+ categories like coding, writing, marketing, and business
• Automatically evaluates prompts using multiple AI models (Claude 3, GPT-4 Mini)
• Combines AI and human ratings for an overall score
• Provides transparency with an open AI evaluation prompt

Discussion Link, Original Link

Mock FedCM Integrations [Developer Tools]

11 points, 0 comments

MockFedCM is a free tool for testing FedCM integrations by simulating authentication flows.

• Simulates real-world FedCM authentication flows
• Enables debugging and validation without a production IdP or RP
• Free to use for testing purposes

Discussion Link, Original Link

Brainfork – Create a personal RAG MCP server in seconds [Developer Tools]

11 points, 0 comments

Create a personal RAG MPC server quickly.

• Instant setup
• Personal RAG MCP server
• Fast deployment

Discussion Link, Original Link

Tips for getting great Text2Cypher outputs from LLMs for Graph RAG [Developer Tools]

4 points, 0 comments

Tips for optimizing Text2Cypher outputs from LLMs for Graph RAG, including schema format comparisons and context engineering.

• Compares JSON, XML, and YAML graph schema formats for LLM interpretation (format impact is minimal)
• Emphasizes context engineering and retaining relevant schema parts in prompts
• Provides graph schema design tips for both LLMs and humans
• Includes experimental results on the LDBC dataset with latest LLMs
• Code and detailed blog post available for reference

Discussion Link, Original Link

Mark 1.0, a notation that unifies JSON, HTML, JSX, XML, YAML, and more [Developer Tools]

7 points, 10 comments

Mark 1.0 is a unified notation combining JSON, HTML, XML, and more into a clean syntax for data and markup.

• Unifies object and markup data formats
• Clean, succinct syntax
• Aims to improve web data storage and exchange
• Version 1.0 released with future improvements planned

Discussion Link, Original Link

Child Affordability Index [Finance]

4 points, 3 comments

Child Affordability Index is a tool to measure the financial feasibility of raising children.

• Measures cost of raising children
• Provides financial feasibility insights
• Helps in family planning decisions

Discussion Link, Original Link

Fluent-state: a new fresh take on local React state [Developer Tools]

5 points, 1 comments

A lightweight React hook that replaces useState, useReducer, useMemo, and useEffect with a fluent API.

• Fluent, proxy-based API for easy state updates
• Immutable updates without spread logic
• Automatic dependency tracking
• Built-in compute for reactive, memoized derived state
• Built-in effect for reactive side-effects
• Zero boilerplate, designed for local state and nested structures

Discussion Link, Original Link

Self-made web media player without <video> or <audio> [Video]

8 points, 6 comments

A web media player built without using HTML5 video or audio tags, powered by Mediabunny and WebCodecs.

• Uses Mediabunny for media handling
• Leverages WebCodecs for decoding
• No reliance on traditional HTML5 video/audio elements
• Custom implementation for media playback

Discussion Link, Original Link

UML is dead – so I'm building the tool to revive it [Developer Tools]

5 points, 3 comments

RapidChart is a modern, developer-first tool designed to revive UML diagramming with speed and flexibility.

• Cursor-style interface for rapid diagram creation
• Fully customizable and exportable
• AI-assisted, compatible with GPT-4 and Claude
• 100% free to use

Discussion Link, Original Link

Take – process file lines with a logic-like language [Developer Tools]

3 points, 0 comments

Process file lines using a logic-like language.

• Processes file lines efficiently
• Uses a logic-like language for operations

Discussion Link, Original Link