Chronos — Git Time-Travel

Chronos provides deep git intelligence, enabling the LLM to understand not just what the code does, but why it was written that way.

Capabilities

• Blame intelligence — Who changed what line and when
• Commit history — Full log with filtering by file and line range
• Churn analysis — Identifies volatile files and hotspot regions
• Temporal decay — Exponential decay on hotspot scores: raw_score × e^(−λ × days) (λ default 0.01). Recent activity weighs more than ancient changes.
• Co-change detection — Finds files that always change together
• Semantic classification — Tags commits as fix, feature, refactor, revert, security
• Risk assessment — Combines churn, fix frequency, and revert history
• Convergence rate — Tracks fix-chains (consecutive fix commits within 48h). convergence_rate = 1.0 − (fix_chains / total). High convergence means the codebase is stabilizing.
• Rigidity — rigidity = fix_chains / total. High rigidity signals a file trapped in a fix-break cycle.

How It Works

Chronos uses libgit2 (via the git2 crate) for direct repository access — no subprocess calls, no git binary dependency.

Git Repository (.git/)
  → libgit2 bindings
  → Blame analysis (line-level attribution)
  → Commit walker (filtered by path/line range)
  → Semantic tagger (regex on commit messages)
  → Churn calculator (edit frequency × temporal decay)
  → Co-change detector (files in same commits)
  → Fix-chain detector (consecutive fixes within 48h)
  → Convergence & rigidity metrics

Semantic Commit Tags

Tag	Pattern	Example
FIX	fix, bug, patch, hotfix, resolve	"Fix null pointer in auth"
REVERT	revert, rollback, undo	"Revert broken migration"
REFACTOR	refactor, cleanup, rename, restructure	"Refactor handler logic"
SECURITY	security, vulnerability, CVE, XSS, injection	"Fix SQL injection in query"
FEATURE	feat, add, implement, introduce, new	"Add OAuth2 support"

MCP Integration

Tool	Description
blame	Get blame data for a file and line range
analyze	Full file analysis: churn, co-changes, risk, semantic tags, convergence rate, rigidity

Usage Example

# Blame a file region
synapseed blame src/auth.rs --start 10 --end 30

# Analyze file history with churn, co-changes, risk
synapseed analyze src/auth.rs