What is Horologium?

Public Alpha. Horologium v0.0.1 is a self-hosted validation slice, not a GA product. See Public Alpha limitations before you rely on anything here for a real decision.

Horologium is a self-hosted Product Truth & Integrity platform. It maintains one canonical, reconciled truth about a software product — its shape, its cross-source integrity conflicts, its deployment reality, and its temporal history — and exposes that truth consistently to humans (a web dashboard) and to coding agents (MCP).

The problem it answers

Software claims accumulate across layers — intent, documentation, code, tests, releases, deployments — and those layers drift out of sync silently:

• A ticket says Done. The code that implements it disagrees with the docs about how it behaves.
• A feature is released in a tagged version, but production is still running an older one. "Done in Jira" is not the same fact as "live for customers."
• Nobody can say, precisely and with a citation, why they believe a given fact about the product is true today — or was true last month.

Horologium reconciles those layers into one queryable Product Truth, with full evidence provenance for every fact, instead of letting each source (a tracker, a doc, a deployment record) assert its own version of reality.

How it gets there — deterministic first, models only where necessary

Horologium does not answer "what's true?" by asking a language model. It:

1. Collects deterministic evidence from the systems that already hold the facts — a Git repository, a Jira project, a documentation site, a deployment record.
2. Reconciles that evidence with deterministic rules wherever the fact is machine-verifiable: commit ancestry, git tag containment, timestamp ordering, an explicit ticket-key reference in a commit message.
3. Uses a language model only where a human would also have to read prose and judge — "does this paragraph describe the refund window, and what does it say?" — and only to produce a proposal, which the Rust core validates against existing evidence and typed rules before it can become part of Product Truth.

Every fact Horologium reports carries its derivation (observed — read directly from structured data, or inferred — extracted from prose by a model-backed proposal that was accepted) and cites the exact evidence it rests on. See Integrity states and evidence for how that citation model works.

Where to go next

• Reality layers — the Implemented → Released → Deployed → Enabled → Observed vector, and why Horologium never collapses it into one status.
• Integrity states and the evidence model — claims, conflicts, and "why do we believe this?"
• Product Shape and temporal history — canonical references and asking what was true at a point in time.
• Self-host quickstart — run Horologium against your own stack.
• Evidence sources — connect Git, Jira, documentation and deployment evidence.
• MCP / coding-agent integration — let a coding agent query Product Truth directly.
• Hosted demo walkthrough — see it running against a synthetic fixture, no install required.
• Security, privacy and data boundaries
• Public Alpha limitations and troubleshooting

Horologium's architecture decisions live as ADRs in the repository (docs/adr/) — this site is the public-facing explanation of what those decisions add up to, not a replacement for them. Where this site and an ADR ever disagree, the ADR is normative.