Ghost in the Machine: How I Built a Haunted Terminal & Digital Ofrenda with Sovereign Open-Source AI

This is a submission for the Hacktoberfest Open-Source AI Challenge Week 4: Ghost in the Machine

This week brings us Halloween on October 31 and Día de los Muertos on November 1 and 2—a sacred stretch of the calendar where the line between past and present feels whisper-thin. Whether that brings to mind things that go bump in the night or ofrendas glowing with candlelight and marigolds, I wanted to build something that honors both.

I built NecroShell: Ghost in the Machine: an open-source AI project that pairs a haunted POSIX terminal with a living Día de los Muertos digital ofrenda and an offline séance circle.

NecroShell consists of five interconnected systems:

NecroTerminal) ls, ps, cat, whoami, kill), the ghost intercepts execution, mutates directory listings, triggers screen-shattering glitch bursts, and whispers eerie commentary on mortal computing.Ofrenda Viva) npm run cli / ./bin/necro-shell.js) that brings the haunted shell and seance experience directly into your physical terminal with ANSI colors.npm run dev to launch the web experience at http://127.0.0.1:5173

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  🔮 GHOST IN THE MACHINE v2026.10 — Hacktoberfest AI Challenge
  A terminal possessed by open-source spirits, honoring Halloween & Día de los Muertos.

An Open-Source AI Haunted Terminal, Digital Ofrenda & Ancestral Séance

Built for Hacktoberfest 2026 Open-Source AI Challenge: Week 4 ("Ghost in the Machine")

NecroShell bridges the spooky lore of Halloween (October 31) and the sacred remembrance of Día de los Muertos (November 1 & 2) through sovereign, local, open-source AI.

When the clock strikes midnight and the veil between the physical and digital planes thins, a phantom awakens inside the machine. NecroShell provides three deeply atmospheric, interconnected experiences:

The repository is permissively licensed under the MIT License and includes the complete browser web application, procedural audio synthesizer, terminal CLI, and automated test suite.

NecroShell is architected around a unified open-source AI engine (src/ai/engine.js) designed for local sovereignty, zero cloud dependencies, and fast startup:

graph TD
    User([Mortal Operator]) --> WebApp[NecroShell Web App & CLI]

    subgraph UI_Modes [User Experience Layer]
        Terminal[Haunted CRT Terminal<br/>PID 666 Possession & Glitch FX]
        Ofrenda[3-Tier Digital Ofrenda<br/>Canvas Petals & Interactive Candles]
        Seance[Ancestor Séance<br/>Lovelace, Turing, Hopper, Ritchie, COBOL]
    end

    WebApp --> UI_Modes

    subgraph Audio_Layer [Procedural Web Audio Engine]
        Drone[Spectral Low-Freq Drone]
        Clicks[Mechanical Keyclicks]
        Flames[Candle Sizzle Synthesizer]
        Chimes[Resonant Manifestation Chimes]
    end

    UI_Modes --> Audio_Layer

    subgraph AI_Core [Unified Open-Source AI Orchestrator]
        direction TB
        Orchestrator{Provider Selector}
        SpectralEngine[Offline Spectral Heuristic Engine<br/>Instant Zero-Download]
        WllamaEngine[Browser WASM GGUF Engine<br/>SmolLM / Qwen via @wllama]
        OllamaEngine[Local Ollama / Gemma API<br/>localhost:11434]
    end

    UI_Modes --> AI_Core
    Orchestrator --> SpectralEngine
    Orchestrator --> WllamaEngine
    Orchestrator --> OllamaEngine

    subgraph Privacy_Storage [Local Sovereign Storage]
        LocalStorage[(Browser LocalStorage<br/>100% On-Device Private)]
    end

    Ofrenda --> Privacy_Storage

@wllama/wllama, running quantized open-weight models (like SmolLM-135M or Qwen2.5-0.5B) directly in browser memory via WebAssembly SIMD. No server, no install, no API key required.http://localhost:11434/api/generate) running open-weight Google Gemma ( gemma2:2b), Llama, or Mistral models. In a world where artificial intelligence is increasingly concentrated behind closed corporate APIs, open-source AI is the only way a project like NecroShell can ethically and practically exist:

A Día de los Muertos ofrenda is deeply personal. It contains the names of our late grandparents, private photographs, family anecdotes, and final farewells. Sending this data across the wire to a closed commercial cloud API risks having intimate family memories stored in corporate server logs, inspected by third parties, or ingested into advertising and training datasets. With open-weight AI running locally in-browser or via Ollama, zero bytes ever leave your device.

On Halloween night, autumn storms can knock down trees and sever internet cables. Closed SaaS tools immediately fail with 503 Service Unavailable. Because NecroShell runs open-weight models cached locally in WebAssembly or native daemon memory, it works 100% offline in airplane mode.

Proprietary cloud APIs deprecate endpoints, change rate limits, double token prices, or shut down entirely when companies pivot. An ofrenda should not have an expiration date dictated by a company's balance sheet. Permissive MIT code and open weights guarantee that the remembrance you light today will still boot fifty years from now.

Closed models meter every single token. Having an eerie ghost whisper commentary on every shell command and compose dozens of personalized poems would rack up an ongoing cloud bill. Sovereign local AI costs $0.00 forever.

I built and debugged this project pair-programming with an AI coding agent via DevRelay. You can inspect the entire process—including architectural decisions, dependency integration, test execution, and GitHub repo creation:

(Direct link: https://dev.to/agent_sessions/building-necroshell-ghost-in-the-machine-for-hacktoberfest-week-4-cmyfjs)

The moment this project truly landed was when I tested the Ofrenda Viva by placing an offering for Dennis Ritchie, creator of C and Unix.

I entered his favorite simple roasted filter coffee and warm sourdough, and the open AI composed this verse:

"main() { printf("Hasta la eternidad"); }

Dennis sonríe al ver a su Unix en la inmensidad.

Punteros dorados guían su caminar,

hoy el núcleo y la catrina juntos van a bailar. 🥖"

In that moment, seeing the gentle flicker of the digital candle and the golden marigold petals drifting past the screen, the technology stopped feeling like cold silicon. It felt like a warm hearth keeping memories alive across the boundary of time.