ix-impact

## Argument parsing Strip `--save` and any following path token from `$ARGUMENTS` before resolving the target. - If `--save <path>` is present, set `SAVE_PATH` to that path. - If `--save` is present without a path, auto-generate `ix-impact-<target-slug>.md` in cwd (target slug = the target with spaces and slashes replaced by `-`). - If `--save` is absent, `SAVE_PATH` is empty — do not write a file. ## Pro check (optional) Call `ix_briefing` with `{}`. If `ok` is `true`, Pro is available. Extract `data.plans` for use in Pro steps below. If it returns `ok: false`, skip all **[Pro]** labeled steps. ## Goal Answer: *what breaks if this changes, and is it safe to proceed?* Stop as early as the risk level allows. ## Phase 1 — Risk score (always) Call both in parallel: - `ix_impact` with `{ "target": "<target from $ARGUMENTS>" }` - `ix_explain` with `{ "symbol": "<target from $ARGUMENTS>" }` **God-module check:** If `facts.calleeCount > 20 AND facts.callerCount < 2` in the `ix_explain` result: > ⚠ This symbol has high callee count and low caller count — it reaches out to many dependents but has few callers. Standard blast-radius metrics may understate risk. Check callers of its key dependencies, not just direct dependents. This caveat applies regardless of the `ix_impact` risk classification. **Immediately classify using `risk_level` and `dependents` from the `ix_impact` result:** | Risk level | Action | |---|---| | `low` + `dependents` < 3 | **STOP** — safe to proceed. Report and suggest verification targets. | | `medium` OR `dependents` 3–10 | Go to Phase 2 | | `high` or `critical` OR `dependents` > 10 | Go to Phase 2 + 3 | ## Phase 2 — Callers and dependents (medium/high/critical) Call both in parallel: - `ix_callers` with `{ "symbol": "<target>" }` (limit 15 per token-budgets rule) - `ix_depends` with `{ "symbol": "<target>", "depth": 2 }` Extract: direct callers by name and subsystem, transitive dependent count from `traversal.nodes_visited`. **Stop here if risk is `medium`:** report callers, suggest verification, done. ## Phase 3 — Import chain and subsystem spread (high/critical only) Call `ix_imported_by` with `{ "symbol": "<target>" }`. Cross-reference callers + dependents + importers to identify: - Which subsystems are in the blast radius - Whether the change crosses an architectural boundary - Any tests that cover the affected paths ## Output ``` ## Impact: [target] **Risk level:** <critical | high | medium | low> **Verdict:** <SAFE TO PROCEED | REVIEW CALLERS FIRST | NEEDS CHANGE PLAN> **Blast radius:** - Direct dependents: N - Transitive (depth 2): M - Subsystems affected: [list — only if phase 3 ran] **Key callers:** [top 5, with subsystem label] **At-risk behaviors:** [from ix_impact at_risk_behavior field] **Recommended action:** - low: proceed, verify [specific callers] - medium: test [caller list] after change - high/critical: run `/ix-plan <target>` before editing **Known bugs in blast radius:** [Pro only — list open bugs touching callers/dependents, or omit section if none/Pro unavailable] ``` ## Phase 4 — Known bugs in blast radius **[Pro]** If Pro is available and `data.plans` from the briefing references this target area, cross-reference open plans against the direct callers and dependents identified in Phase 2. Any active plan touching the blast radius escalates the risk verdict — flag it explicitly in the output. Never read source code in this skill. Risk analysis is purely graph-based. ## Save step **Only if `SAVE_PATH` is non-empty:** - Write the full output to `SAVE_PATH`. - Confirm to the user: `Saved to <SAVE_PATH>`. - Do not write the file if `--save` was not passed.