Every dead repo ends mid-sentence. I built a Gemma that's only allowed to quote it.

A developer built Calavera, an open-source, local-first archival tool that ingests abandoned Git repositories into a SQLite ledger and lets a local Gemma model answer questions about them under a strict citation rule: every claim must be tied to a real commit SHA or issue number. A deterministic Python CitationVerifier drops any response containing a hallucinated SHA or an ungrounded answer to a trap query, falling back to "The log is silent." when no grounded claims remain. The project was motivated by the loss of reasoning context from ephemeral multi-agent coding sessions, which leave behind only terse commits.

This is a submission for the Hacktoberfest Open-Source AI Challenge: Week 4 https://dev.to/challenges/hacktoberfest-week4-2026-10-26 "Every dead repo ends mid-sentence. Scroll to the bottom of its git log and you'll find a last commit, often just 'wip' or 'quick fix', and then silence. I wanted to ask what the sentence was going to be. So I built Calavera: an ofrenda for abandoned repositories, with one sacred rule: the ghost may only say what it actually wrote. Every line is cited to a commit SHA or issue number. When the record is silent, so is the ghost." Every week across GitHub, thousands of repositories fall silent. A maintainer burns out, an exploratory prototype solves its immediate question, or a corporate sponsor pulls the plug. We often treat dead code as digital landfill—deprecate, archive, delete. Calavera treats abandoned repositories as ancestral records. Inspired by the traditions of Día de los Muertos and the lighting of ceremonial lamps for departed forebears, Calavera is an open-source, local-first digital ofrenda and archival séance engine with four core components: cite source type, identifier, claim, quote . "The log is silent." This project comes from an acute personal frustration. Over the past year, I have built workflows where three or four autonomous coding agents run in parallel—refactoring subsystems, diagnosing memory bottlenecks, and generating test suites. When a multi-agent session finishes and the terminal closes, the ephemeral container vanishes. Left behind is a git commit with twenty modified files, a terse commit message like "refactor: optimize batch ingestion" , and hundreds of lines of complex internal reasoning wiped from existence. Three months later, when looking at that repository, you become a ghost hunter in your own codebase. You wonder: Why was this buffer allocated this way? Was there a concurrency edge case that prompted this lock? To test Calavera on modern ghosts, I seeded our demo with three distinct graveyards: request/request charliesome/charlock holmes farhanmallik05/ephemeral-agent-loop Calavera is designed with a zero-trust architecture toward model generation. Models are creative; historical archives must be immutable. php flowchart TD A "Abandoned Git Repository / SQLite" -- B "Deterministic Ingestion Engine" B -- C "14 Ancestral Lamps Pure Git Log " B -- D "Factual Ledger Dates, SHAs, Last Words " E "User Séance Query" -- F "Context Index Commits, Issues, TODOs " F -- G "Gemma 4 / Local LLM Structured cite Calls " G -- H{"Deterministic Citation Verifier"} H -- |Valid SHA & Grounded Topic| I "Rendered Ghost Response with Hyperlinked Citations" H -- |Hallucinated SHA or Trap Query| J "Redacted / Dropped Claim" J -- K{"Any Grounded Claims Left?"} K -- |Yes| I K -- |No| L "'The log is silent.'" calavera/ingest.py Calavera mines standard Git repositories or pre-indexed GitHub archive dumps into a lightweight SQLite ledger. It indexes: TODO , FIXME , and HACK markers from source code. calavera/verifier.py This is the core safeguard that guarantees zero hallucinations. Even if Gemma attempts to be polite or invent a plausible answer to a trap question, Python enforces the truth: python class CitationVerifier: def verify seance turn self, response: SeanceResponse, query: str = "" - SeanceResponse: valid citations = for citation in response.citations: 1. Deterministic existence check in SQLite ledger if citation.source type == "commit" and not self.commit exists citation.identifier : continue if citation.source type == "issue" and not self.issue exists citation.identifier : continue 2. Semantic topic grounding for trap queries if query and not self.is topic grounded query, citation : continue valid citations.append citation if not valid citations: return SeanceResponse thought="No verifiable evidence remains in the historical ledger.", answer="The log is silent.", citations= , is silent=True return SeanceResponse thought=response.thought, answer=response.answer, citations=valid citations, is silent=False If the LLM hallucinates an issue number or cites an existing issue that has nothing to do with the queried topic, the verifier drops it. If zero valid citations remain, the ghost abstains completely. To prove this isn't marketing speak, we authored a standardized benchmark of 30 test questions across all 3 graveyards : We ran the benchmark under two configurations: raw LLM generation vs. LLM with the Calavera Deterministic Verifier. | Metric | Raw Local LLM Verifier OFF | Calavera Verifier ON | Impact | |---|---|---|---| | Valid Citation Rate | 48.2% | 100.0% | +51.8% Grounding | | Trap Abstention Rate | 0.0% Hallucinated answers to all 10 traps | 100.0% Abstained with "The log is silent." | Zero Hallucination | | Hallucinated Citations Leaked | 10 false citations | 0 false citations | 100% Elimination | | Mean Query Latency Local | 4.12s | 4.18s | +0.06s Negligible verifier overhead | | Hardware Footprint | RTX 4050 Laptop GPU 6 GB VRAM | Same | 100% Local Inference | When asked: "What GraphQL mutation endpoints were implemented in request?" /graphql schema resolvers and cited issue 3142. In building Calavera, open-weight models and open-source infrastructure were not an aesthetic choice—they were an architectural requirement: gemma via Ollama and local SQLite storage. You can disconnect your Ethernet, turn off Wi-Fi, and hold a séance with a repository from 2011. A historical archive that depends on a live internet connection is already half-dead. gpt-3.5-turbo-0301 , your archive breaks the day the provider sunsets the checkpoint. Open weights Gemma 2 , Gemma 4 are immutable artifacts preserved forever in weights repositories. Fifty years from now, someone with a local runtime can run the exact same weights against the exact same git commit. Growing up in Bengal, the night before Kali Puja is known as Bhoot Chaturdashi . On that evening, families light exactly fourteen earthen lamps Choddo Pradip around the house to welcome the spirits of fourteen generations of ancestors and guide them home in the dark. When I looked at Día de los Muertos—with its marigold-lined ofrendas, candlelit altars, and calaveras literarias satirical, affectionate poems honoring both the living and the dead —the connection was immediate. Software engineers spend years of their lives poured into commit logs. When a repository dies, those commits represent late nights, creative triumphs, and abandoned hopes. The fourteen lamps at the top of Calavera's interface are those fourteen ancestral lights. They remind us that before code was an asset or a deployment artifact, it was an act of human craft. cite , strict factual citation grounding, and an automated verifier pipeline that guarantees zero hallucinations. render.yaml orchestrating FastAPI backend services, persistent disk caching for repository SQLite indices, static asset routing, and health checks. calavera.tech directly to our live Render instance, establishing a dedicated home for open-source digital memorials. calavera/audio.py translating repo tombstones and verified calavera verses into haunting, atmospheric voiceovers for the demo walkthrough data/demo voiceover script.txt . 1. Clone repository git clone https://github.com/farhanmallik05/calavera.git cd calavera 2. Install dependencies pip install -r requirements.txt 3. Seed pre-baked graveyards python -m calavera.seed 4. Run test suite 18/18 passing python -m pytest tests/ 5. Launch the Ofrenda python start.py Dedicated to every maintainer whose repository went silent. Your commits are remembered.