DEV Community: Mahima

SOWCAST — Know what to sow, right when to sow it

Mahima — Sun, 11 Oct 2026 13:57:09 +0000

This is a submission for the Hacktoberfest Open-Source AI Challenge Week 1: Touch Grass

What I Built

Most gardening guides give you advice like "direct sow 2 weeks after the last spring frost" or "start seeds indoors 6 weeks before final thaw". But for everyday people, beginners, and urban balcony growers, this immediately brings friction: When actually IS the last frost in my neighborhood?

That confusion keeps people glued to screens reading conflicting blog posts and confusing agricultural charts instead of stepping outside into the dirt.

I built SOWCAST to bridge that gap and get people off their screens and into the real world with soil on their hands.

SOWCAST is an offline-first, botanical smart garden planner that tells you exactly what to plant THIS WEEK, based on real 20-year historical climate normals for your exact coordinates.

Key Capabilities:

What SOWCAST Can Do:
"This Week" Dashboard: Tells you exactly what to sow right now, what to start indoors, and what to wait on — with clear reasons based on your local soil temperatures.
Frost Countdown & Alerts: Shows a live countdown to your last frost, plus a 48-hour warning before sudden cold snaps so you can protect your young plants.
Works Anywhere on Earth: Automatically adjusts for cold climates with frost dates, or warm/tropical areas with monsoon and dry seasons.
Interactive Garden Bed Planner: Drag and drop plants into a square-foot grid. It warns you about bad plant neighbors and highlights friendly plants that help each other grow.
64+ Curated Plant Guides: Step-by-step instructions for popular vegetables, herbs, and flowers — including spacing, sunlight, watering, and harvest times.
100% Offline & Private: Saves everything directly on your device. Works without internet, needs no login or backend, and installs right onto your phone like a native app.

Demo

Live Deployed App:

sowcast.vercel.app

Try Demo Garden: You can launch the app and click "Try Demo Garden" on the landing page or dashboard to test it with pre-populated beds and local weather intelligence instantly!
Code

Code

The complete source code is open-source on GitHub:

👉 https://github.com/lohanmahima/SOW_CAST

How I Built It

SOWCAST was crafted with a modern, zero-cost, open-source stack designed for 60fps responsiveness and zero maintenance overhead:

Framework & Language: Next.js 14 (App Router) with strict TypeScript, delivering statically optimized pages and seamless client-side hydration.
Design & Micro-interactions: Tailwind CSS with custom editorial botanical typography (Playfair Display + Plus Jakarta Sans), warm cream paper palettes (#F6F1E7), deep moss greens (#2F4A3A), and Framer Motion spring physics for sprout animations, confetti celebrations, and bed drag-and-drop interactions.
The Frost Engine: Connects to the free, keyless Open-Meteo APIs (Geocoding API, 7-Day Weather Forecast, and the 20-Year Historical Weather Archive). It analyzes decades of daily minimum temperatures to calculate the exact 50% probability freeze-thaw boundary.
Client-Side Storage Engine: Powered by Dexie.js (IndexedDB) with relational reactive live queries (useLiveQuery). All user beds, custom plantings, journal photos, growth milestones, and care checklists persist locally on device.
_Autonomous AI Agent Harness: _Built in deep collaboration with an autonomous agentic pair programming harness (Google Antigravity). The agent assisted with mathematical frost curve modeling, synthesizing the companion planting conflict matrix for 64 botanical species, and architecting the square-foot grid coordinate system.

Why Does Open Innovation Matter?

Food growing and climate resilience shouldn't be locked behind proprietary paywalls, opaque subscriptions, or corporate garden apps that sell your data.

_Open innovation made SOWCAST possible in two fundamental ways:
_
Open Meteorological Science: The Open-Meteo project provides open-access historical weather data and global forecasts without API keys or rate-limit paywalls. Closed APIs typically charge thousands of dollars for decades of archived minimum temperature readings, pricing out independent developers and hobbyist gardeners.
Browser-Native Standards: Using open web standards—IndexedDB for zero-cloud client storage, Web Push / Notification APIs, Service Workers for PWA offline capabilities, and SVG vector graphics—SOWCAST runs entirely on the user's hardware with zero operational infrastructure costs.

Open innovation proves that individual developers can build production-quality tools that empower people to grow their own organic food and reconnect with nature.

My Agent Session

This project was built from conception to production using the Antigravity agentic coding environment. The agent executed end-to-end full-stack workflows:

Initialized the Next.js 14 App Router architecture and Dexie database schema.
Researched companion planting matrices and built the spatial conflict engine.
Wrote the Open-Meteo statistical freeze calculation algorithms.
Iteratively tested production builds (npm run build), eliminated all TypeScript errors, and packaged PWA service worker manifests.

Prize Categories

Best Overall Project
Getting People Out into the Real World (Bridging technology to dirt, soil, and organic food cultivation)
Best Use of Open-Source AI / Open Innovation Tools

I built a strict local AI for my friend so he could actually learn to code

Mahima — Mon, 05 Oct 2026 07:53:46 +0000

This is a submission for the Hacktoberfest Weekend Challenge: Build for a Friend

What I Built

I built RootCause for my friend, Ojju. Ojju is learning how to code and kept getting stuck on logic problems. Every time he asked AI tools for help, they would just hand him the entire correct code. It solved the problem, but it ruined his learning process because it didn't teach him how to think.

RootCause is an AI learning companion that strictly refuses to give you the answer. Instead, you paste your broken code and explain your thought process. It diagnoses exactly why you are stuck (e.g., a logic flaw, a missing concept, or a missed edge case) and guides you back to the right path with progressive Socratic hints. It also tracks your weak spots and generates micro-exercises in a "Logic Gym" so you can practice your mistakes.

Code

lohanmahima / RootCause

AI learning companion that diagnoses WHY you're stuck on coding problems instead of handing you answers. Socratic hints, targeted micro-exercises, and learning memory. Runs locally with Ollama + Gemma.

RootCause

RootCause is a coding companion that diagnoses why you are stuck instead of giving you the answer.

I built this for a friend, Ojju, who was learning to code but kept getting stuck on logic errors. When he used standard tools, they handed him the corrected code immediately, which solved the problem but didn't help him learn how to fix it himself next time. RootCause forces you to explain your approach first, reads your broken code, and points out the specific conceptual or logic gap you are missing.

[TODO: one real thing Ojju said after trying it]

Live Demo

You can access the live version of this application here ?? Live Demo (Note: Initial startup may show a security warning. Click "Continue" to proceed. This URL requires the host laptop to be online).

Screenshots

What it does

Solve flow: You explain your approach, paste your broken code, and provide…

View on GitHub

How I Built It

RootCause is built entirely around local inference using open-weight models.

Frontend & App Logic: Python with Streamlit. I built a custom sandboxed Python environment to safely evaluate the user's Logic Gym code using subprocess and ast.
AI Engine: Google's Gemma 3 (4B) model, running locally via Ollama.
Data Persistence: SQLite for tracking topics, XP, and daily streaks locally.

The app uses Gemma 3 through Ollama's Python client to act as a strict tutor. I designed specific system prompts to force the model to output JSON judgments ({"met": false, "feedback": "...", "thinking_trick": "..."}) instead of free text. If the local Ollama instance crashes or runs out of memory, I built a silent fallback mechanism that automatically switches the Logic Gym to a verified offline bank of hand-written exercises so the user's workflow is never interrupted.

Why Does Open Innovation Matter?

Open innovation made RootCause possible because a learning tool for students needs to be free and private. If I built this on a closed API, Ojju would eventually have to pay per prompt, or I would have to pay a server bill to keep it running for him. By using an open model like Gemma 3 running locally via Ollama, it costs absolutely nothing. Ojju can use it offline on an airplane, and his messy, broken code never leaves his laptop.

Prize Categories
Open Innovation

From AI/ML Student to AI Agent Builder

Mahima — Sun, 23 Aug 2026 15:02:45 +0000

I’m a B.Tech CSE (AI & ML) student focused on building practical software and AI-driven applications. Interested in Artificial Intelligence, cloud computing, and emerging technologies, with a strong focus on continuous learning and hands-on development. Currently exploring different technologies and development approaches to strengthen my technical skills and build scalable, real-world solutions.

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