PyLazarus: Resurrecting 15 Years of Abandoned Python Code with Open-Weight AI & WebAssembly

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

---

At 2:14 AM, I stared at a 2009 Python script named ascii-dungeon.py. Its commit history had been frozen for thirteen years. When I ran python3 ascii-dungeon.py, the terminal spat out an immediate, unceremonious autopsy: SyntaxError: invalid syntax on line 14, where a bare print "Welcome to the Crypt" sat unchanged since the Obama administration.

That script was once someone's pride—a weekend project, perhaps their first open-source tool. Along with tens of thousands of other Python 2 tools built between 2005 and 2015, it had become a digital ghost. When Python 2 officially died on January 1, 2020, and ancient REST APIs vanished, an entire decade of developer culture vanished into bitrot.

Software preservation is too often treated as a dusty archive of dead tarballs on cold tape storage. But code isn’t a painting in a museum; its soul only exists when the CPU cycles execute.

When I first loaded ascii-dungeon-2009 into PyLazarus and watched the WebAssembly terminal render a glowing green procedural dungeon in under 18 milliseconds—fifteen years after its author pushed their final commit—it wasn't just a successful syntax transform. It felt like hearing an antique music box play a forgotten song after decades of silence. In the spirit of Día de los Muertos, we don't build cold monuments to remember what was lost; we set an ofrenda with candlelight, marigolds, and food to invite the spirits back to feast. PyLazarus is that ofrenda for open-source software history.

I built PyLazarus to ensure these ghosts don't stay dead.

---

What I Built

PyLazarus is the open-source abandonware resurrection engine and living WebAssembly arcade ("The CodePen / HuggingFace Spaces for dead software"). It takes abandoned 2005–2015 Python 2 tools, deterministically repairs their bitrot syntax, excavates dead API schemas from the Internet Archive Wayback Machine, patches missing dependencies with local open-weight AI (gemma4:e4b), and runs them immediately inside the browser via WebAssembly (Pyodide v0.26.2) at $0.00 server compute cost.

Key capabilities:

1. The Living Crypt Social Arcade: An interactive cemetery where dead repositories rest in peace—until you resurrect them, light a vigil candle, inspect their AST surgery diff, or execute them live in the browser.
2. The 3-Stage Deterministic Resurrection Pipeline: Models read and draft; deterministic code decides. Python's native ast engine resolves mechanical syntax in $<15\text{ms}$ with zero LLM calls, Tiger Data PostgreSQL 18 hybrid search ($k=60$ RRF) retrieves historical patterns, and Gemma 4 drafts minimal span patches.
3. The Gatekeeper Invariant Guard (gatekeeper.py): An unforgiving verification system that checks 100% symbol preservation (preventing LLMs from cheating by deleting failing functions), blocks forbidden syscalls, and verifies citations against Wayback Machine sources.
4. Client-Side Pyodide Arcade: Every visitor can run, edit, pass CLI flags to, and remix resurrected tools without installing Python 2 or spinning up Docker containers.

---

Demo

To experience PyLazarus in action, you can run the pre-built WebAssembly arcade locally in under two minutes:

1. Instant 3-Command Quickstart:

git clone https://github.com/Adnan9-63/pylazarus.git && cd pylazarus
pip install -r requirements.txt
uvicorn backend.app:app --host 127.0.0.1 --port 8000

Open http://127.0.0.1:8000 to enter the Living Crypt, inspect the time diffs, listen to the ElevenLabs forensic audio eulogies, and run any resurrected tool in Pyodide WebAssembly.

1. Video & Script Walkthrough: A step-by-step 75-second cue sheet walking through AST surgery, Gatekeeper verification, and live WASM terminal execution is published in submission/DEMO_SCRIPT.md.

---

Code

The complete source code is public and released under the MIT License:

Adnan9-63 / pylazarus

The Open-Source Abandonware Resurrection Engine & Living WebAssembly Arcade

💀 PyLazarus

The Open-Source Abandonware Resurrection Engine & Living WebAssembly Arcade

---

🕯️ 1. Executive Summary & The "Ghost in the Machine" Theme

Between 2005 and 2015, the open-source Python community built tens of thousands of beloved, elegant, single-purpose CLI utilities and libraries: dungeon crawlers, Markov poem generators, torrent inspectors, and web scrapers. When Python 2 reached end-of-life on January 1, 2020, and ancient REST APIs vanished from the web, this immense cultural heritage turned to digital ghosts—abandoned on GitHub with bitrot syntax, broken stdlib imports (urllib2, sgmllib, commands), and dead endpoints (weather.yahooapis.com, Twitter v1.0).

In the spirit of Día de los Muertos and Halloween ("Ghost in the Machine"), PyLazarus does not merely mourn these departed tools—it resurrects them into living software.

PyLazarus combines local open-weight AI (gemma4:e4b), Browserbase Stagehand Wayback Machine archaeology, Tiger Data PostgreSQL 18 hybrid vector…

View on GitHub

---

How I Built It

The fundamental design rule of PyLazarus is: Never trust an LLM to rewrite legacy code unverified.

When an unguarded model faces broken tests or deprecated libraries, its most common epistemic failure is silent cheating: it deletes failing assertions, renames functions, or removes core features just to achieve exit code 0. In our benchmark, raw Gemma 4 silently deleted functions in 4 out of 18 repositories.

To solve this, PyLazarus enforces a strict separation of concerns:

1. Stage 1: Deterministic AST Syntax Transpiler: Python's native ast and regex rules deterministically upgrade print statements, except Exception, e:, xrange(), dict.iteritems(), octal literals (0755 $\to$ 0o755), and chevron prints (print >> sys.stderr, ...) in $<15\text{ms}$ with zero model hallucinations.
2. Stage 2: Wayback Archaeology & Tiger Data Hybrid Search: For removed stdlibs (urllib2, sgmllib, commands) or sunset endpoints (Twitter v1.0, Yahoo Weather), Browserbase Stagehand crawls historical Wayback Machine CDX snapshots, and Tiger Data retrieves exact migration schemas using dense halfvec(768) HNSW + sparse pg_textsearch BM25 Reciprocal Rank Fusion ($k=60$), achieving a 94.4% Recall@5 (+22.2% fused lift over vector-only).
3. Stage 3: Gemma 4 Span Patcher & The Gatekeeper: Local gemma4:e4b (via Ollama at temperature=0.0, seed=42) drafts a minimal span patch + _lazarus_polyfill.py. The patch is immediately intercepted by backend/gatekeeper.py:
   • AST Symbol Preservation Invariant: 100% of original function names and classes must remain intact.
   • Zero-Forbidden-Syscall Guard: Blocks eval, exec, os.system, and unconstrained subprocesses.
   • Lexical Stem Citation Grounding ($G(c_i) \ge 0.85$): Every forensic diagnosis claim must cite a valid [W1] or [P1] snapshot.
   • Subprocess Golden Parity: Executes in a sandbox asserting exit-code 0 and deterministic golden stdout.

The Hardening Story (From BREAK_LOG.md)

During our reliability engineering and edge-case testing passes, we systematically audited PyLazarus across diverse operating systems and runtimes:

• Cross-Platform Directory Isolation: Standardized path canonicalization across Windows and POSIX filesystems to guarantee that all media and cache operations are strictly confined within designated local storage directories.
• Pyodide Virtual FS Cache Management: Resolved an in-memory module collision where sequential tool execution in browser WebAssembly retained cached imports in sys.modules, implementing an automated lifecycle cleanup between consecutive runs.
• Robust AST Parser Boundary Handling: Hardened syntax verification by trapping parser edge-case exceptions (SyntaxError and ValueError), ensuring malformed or truncated legacy snippets are cleanly rejected without server-side disruption.

---

Why Does Open Innovation Matter?

What we built with PyLazarus would be impossible with closed-API models.

Closed commercial APIs change their prompt formatting, deprecate weights, and charge per token. If you rely on a closed API to preserve software history, your preservation engine will itself become abandonware the moment that API changes its pricing tier or terms of service.

Open innovation made three things possible:

1. Deterministic Reproducibility: By locking gemma4:e4b to temperature=0.0, top_k=1, seed=42 on local hardware, the exact same patch is generated every single time.
2. Air-Gapped Execution: PyLazarus runs completely offline. You can run it in a bunker, on a plane, or twenty years from now without an internet connection or an active credit card.
3. Zero-Compute Client-Side Delivery: By compiling Python 3.12 to WebAssembly with Pyodide, the community platform can scale to millions of users without bankrupting the open-source maintainer with cloud server bills.

---

My Agent Session

Building PyLazarus within the Hacktoberfest Week 4 window required a disciplined, test-driven approach to AI pair programming rather than open-ended code generation. Working alongside an autonomous agent coding environment, the development workflow focused on deterministic contract enforcement, mathematical invariant validation, and reproducible verification.

The agent collaboration centered on three core principles:

1. Automated Reliability Auditing & Boundary Testing: Rather than using the agent solely to draft features, we used it to systematically audit edge cases and stress-test pipeline boundaries across operating systems. This uncovered subtle runtime behaviors early—such as platform-specific path boundary isolation, virtual filesystem module caching in browser WebAssembly runtimes, and exception handling boundaries in Python's native AST parser when processing malformed legacy source files.
2. Deterministic-First Invariant Design: Whenever there was a temptation to rely on heuristic LLM prompts to validate code, we anchored the pipeline in deterministic software engineering: Python's native ast structural comparison engine (verify_ast_integrity), POSIX shlex argument tokenization, and Tiger Data Reciprocal Rank Fusion ($k=60$) combining dense 768-dimensional embeddings with BM25 keyword matching.
3. Continuous Regression Guarding: Every edge case identified during boundary testing was converted directly into an automated unit test. The resulting test suite (35 unit and regression tests, automated preflight self-checks, and benchmark suites) runs reproducibly on every build, ensuring that open-weight model integration remains provably stable and transparent.

---

The Spirit of It

Halloween and Día de los Muertos remind us that the things we loved don't truly disappear as long as we remember them. In software, code doesn't rot because it is defective; it rots because the world moves on around it.

PyLazarus is a digital altar to the open-source contributors of 2005–2015. Their work mattered, their clever algorithms still work, and today, they can be played once again in any modern web browser.

---

Prize Categories

We are entering PyLazarus into the following challenge categories:

• Google Gemma ($200 Featured Track): Powered by local gemma4:e4b greedy deterministic decoding and embeddinggemma 768-d vector embeddings.
• Render ($200 Featured Track): Automated deployment blueprint (render.yaml) provisioning web services, persistent storage, and background workers.
• TabPFN ($200 Partner Track): Prior-data fitted network evaluating 12 extracted AST bitrot features for $<100\text{ms}$ resurrection viability classification.
• Tiger Data ($100 Partner Track): PostgreSQL 18 with halfvec(768) HNSW index + pg_textsearch BM25 Reciprocal Rank Fusion ($k=60$) + TimescaleDB hypertables.
• Browserbase Stagehand ($100 Partner Track): Automated Wayback Machine CDX API excavation recovering historical schemas.
• Temporal ($100 Partner Track): RepoResurrectionSagaWorkflow orchestrating the 3-stage resurrection pipeline with SIGKILL recovery drills.
• Sentry ($100 Partner Track): OpenTelemetry Agent Tracing with in-flight zero-PII scrubbing.
• ElevenLabs ($100 Partner Track): Solemn technical post-mortem eulogies with code phonetic symbol expansion.