codehub-impact-analysis

Impact Analysis with OpenCodeHub

When to Use

• "Is it safe to change this function?"
• "What will break if I modify X?"
• "Show me the blast radius."
• "Who uses this code?"
• Before committing or merging a non-trivial change.

Decision Tree

Is the target a symbol (function, class, method, property)?
  └─ yes → mcp__codehub__impact
Is the target an HTTP route or API endpoint?
  └─ yes → mcp__codehub__api_impact + mcp__codehub__route_map
Is the change a response-shape edit on a route?
  └─ yes → mcp__codehub__shape_check (find consumer key-access mismatches)
Is the target a dependency version bump?
  └─ yes → mcp__codehub__dependencies + mcp__codehub__license_audit
Want to see what the working tree currently touches?
  └─ yes → mcp__codehub__detect_changes

Workflow

1. mcp__codehub__impact({ name, direction: "upstream", repo })  → Dependents of the target
2. Read confidenceBreakdown                                          → Trust the confirmed count
3. If HTTP-adjacent: mcp__codehub__api_impact + shape_check      → Route + shape mismatches
4. mcp__codehub__detect_changes                                  → Map the current diff to flows
5. Assess risk tier and write the summary

If the context envelope warns the index is stale, run codehub analyze first — stale impact results are worse than no impact results.

Checklist

- [ ] mcp__codehub__impact({ name, direction: "upstream", repo })
- [ ] Review byDepth.d1 first — these WILL BREAK
- [ ] Read confidenceBreakdown; demand confirmed >= heuristic for destructive calls
- [ ] Filter to confidence >= 0.9 if the target is load-bearing (auth, payments, data integrity)
- [ ] If target is a Route: mcp__codehub__api_impact + mcp__codehub__shape_check
- [ ] mcp__codehub__detect_changes to map the current diff to affected processes
- [ ] Produce a risk tier and a one-paragraph summary

Understanding impact output

Risk levels map to blast-radius tiers:

Depth	Risk Level	Meaning
d=1	WILL BREAK	Direct callers / importers / overrides
d=2	LIKELY AFFECTED	One hop through d=1
d=3	MAY NEED TESTING	Two hops — transitive effects