Find Hidden Rules in Your Code - Before You Break Them
Legacy code has invisible rules (contracts) that keep it working. When you modernize with AI, these rules are easy to break. SpecFact automatically finds them and enforces them as runtime checks - so you can refactor safely without breaking production.
How Long Does Analysis Take?
Small codebases
< 30 seconds
< 10 files
Medium codebases
2-5 minutes
Dozens of features
Large/complex repos
10-15 minutes
Hundreds of features
SpecFact performs deep analysis to find the hidden rules in your code accurately. This thoroughness prevents false alarms and ensures the rules we find match what your code actually does.
The Real Risk of Modernization
70% of Fortune 500 software is 20+ years old. When you modernize with AI: AI generates code 10x faster, but the hidden rules that keep your code working are invisible. SpecFact finds these rules before you refactor. Runtime checks catch breaking changes before they reach production.
Learn MoreThe Problem: Why Legacy Modernization Fails
The Solution: Contract Discovery & Enforcement
From Vibe Coding to Verified Specs: How SpecFact Completes the SDD Workflow in DevSecOps
Spec-Driven Development tools like OpenSpec and Spec-Kit create great specs. SpecFact adds the missing enforcement layer that prevents drift, catches regressions, and integrates with your CI/CD pipeline. Here's how executable contracts bridge the gap between intent and implementation.
Read article →OpenSpec Journey: Change Proposals Meet Runtime Enforcement
OpenSpec anchors change proposals and specs. SpecFact adds brownfield analysis, runtime contracts, and DevOps export. This guide shows OpenSpec-first and code-first workflows with commands you can run.
Read article →Spec-Kit Journey: Interactive Specs With Deterministic Enforcement
Spec-Kit slash commands are fast for new specs. SpecFact adds brownfield analysis, runtime contracts, and drift detection for legacy code, then syncs back to Spec-Kit for living documentation.
Read article →code2spec: How SpecFact Reverse Engineers Python Legacy Code
Step-by-step guide to reverse engineering legacy Python code into executable contracts. Learn how SpecFact uses AST analysis, contract generation, and symbolic execution to document undocumented codebases in minutes, not weeks.
Read article →We Dogfooded SpecFact CLI on Itself
We ran SpecFact CLI on its own codebase. In under 10 seconds, it discovered 19 features, found 24 deviations, and blocked a merge.
Read article →Real Results: Bugs Caught & Regressions Prevented
Resources
Getting Started
Install SpecFact and run your first analysis.
Documentation
Complete guides and reference docs.
Agile Team Workflows
Persona-based collaboration for POs, devs, and architects.
Bridge Adapters
Spec-Kit (first). Azure DevOps, Jira, Linear coming.
Discussions
Ask questions, share ideas on GitHub.
Issues
Report bugs or request features.
Ready to lock down your contracts before modernizing?
Start your analysis: uvx specfact-cli@latest import from-code my-project --repo .
Analysis typically takes 2-5 minutes for large codebases, 10-15 minutes for complex repos with hundreds of features.
Or use AI IDE slash commands for LLM-enriched contract discovery: specfact init --ide cursor