ix-plan

name	ix-plan
description	Generate a risk-ordered implementation plan for a set of targets. Assesses blast radius per target, finds data flows between them, and produces a safe change sequence.
argument-hint	<symbol1> [symbol2...] or "description of what you want to change" [--save [path]]

ix-claude-plugin shared model

Check command -v ix first. If unavailable, use Grep + Read to manually assess blast radius per target.

Argument parsing

Strip --save and any following path token from $ARGUMENTS before resolving targets.

• If --save <path> is present, set SAVE_PATH to that path.
• If --save is present without a path, auto-generate ix-plan-<target-slug>.md in cwd (target slug = the first target or first three words of the description with spaces and slashes replaced by -).
• If --save is absent, SAVE_PATH is empty — do not write a file.

Pro check (optional)

Run once at the start:

ix briefing --format json 2>&1

If it returns JSON with a revision field, Pro is available. Extract activeGoals, activePlans, and openBugs for use in Pro steps below. If it errors, skip all [Pro] labeled steps.

Goal

Answer: in what order should these changes be made, what will break, and what needs testing?

Phase 1 — Scope (always)

If $ARGUMENTS contains symbol names, proceed. If $ARGUMENTS is a description (no identifiable symbols), first run:

ix text "$ARGUMENTS" --limit 10 --format llm
ix locate "$ARGUMENTS" --format llm

Identify the 1–4 most relevant symbols and treat those as targets.

Phase 2 — Impact per target (parallel)

For each identified target, run simultaneously:

ix impact  <target> --format llm
ix callers <target> --limit 10 --format llm

Rank targets by risk level: critical > high > medium > low.

Fast path — all low risk: If every target is low risk AND has < 3 dependents, skip Phases 3–5. Go directly to Output with verdict "SAFE — all targets low risk; no additional data-flow, shared-dependent, or project-context analysis needed."

Delegation gate — high-complexity path: If the fast path did not trigger, check for high complexity:

1. From Phase 2 results: does any target have dependents > 20?
2. If not already known, run ix subsystems --format llm (reads cached data — cheap) and check if any non-low-risk target's region has coupling > 5
3. If either condition is true:
   • Spawn ix-safe-refactor-planner with pre-filled context:
     • TARGETS: the resolved symbol list from Phase 1
     • RISK_TABLE: the ranked table from Phase 2 (agent skips its own Steps 1–3)
     • SUBSYSTEMS: subsystems output from step 2
   • Stop — the agent produces the full sequenced plan

Otherwise continue inline with Phases 3–5.

Phase 3 — Data flow (only if 2+ targets AND at least one is medium/high/critical)

Find how the targets connect:

ix trace <highest-risk-target> --to <second-target> --depth 2 --format llm

Run for the most architecturally significant pair. Skip if targets are in independent subsystems.

Phase 4 — Shared dependents (only if high/critical targets exist; skip if all low risk)

ix depends <highest-risk-target> --depth 2 --format llm

Identify if any third symbol depends on multiple targets (shared blast radius — highest testing priority).

Phase 5 — Project context and plan tracking [Pro]

If Pro is available (detected above):

Check for existing plans and goals that overlap with this change:

ix plans --format json
ix goals --format json

Cross-reference activePlans from the briefing to avoid duplicate work. If an existing plan covers these targets, reference it. If activeGoals exist, note which goal this change serves.

At the end of the output, suggest the user create a plan to track execution:

ix plan create "<change title>" --goal <goal-id>

(Only suggest if no existing plan already covers this work.)

Output

# Change Plan

## Targets & Risk

| Target | Risk | Dependents | Key Callers |
|--------|------|------------|-------------|
| <A>    | high | 12         | X, Y, Z     |
| <B>    | low  | 2          | P           |

## Change Order

Edit in this sequence to minimize breakage:
1. [target] — [reason: lowest risk / most-depended-upon first]
2. ...

## Data Flow
[A → trace path → B — or "targets are independent"]

## Shared Risk
[Symbols affected by changes to multiple targets — these need testing after every change]

## Test Checkpoints
After [target A]: verify [specific callers]
After [target B]: verify [specific callers]

## Red Flags
- [any critical/high target needing extra care]
- [any cross-subsystem boundary being crossed]

## Project context **[Pro]**
- Goal this serves: [from ix goals — omit if Pro unavailable]
- Existing plan to track against: [plan ID + title, or "none — suggest creating one"]

Do not read source code in this skill unless a target cannot be resolved by ix locate.

Save step (only if SAVE_PATH is non-empty):

• Write the full output above to SAVE_PATH using the Write tool.
• Confirm to the user: Saved to <SAVE_PATH>.
• Do not write the file if --save was not passed.