rpg-system-file-editor

name	rpg-system-file-editor
description	Edit RPG Companion App system files under systems/<system>/system (such as .rpgs and .rpg.json), including stats formulas, mechanics, views, resources wiring, and combat behavior. Use when asked to adapt rules behavior in an existing system, add/update RPG Script formulas, or troubleshoot system-file logic. Prefer MCP dev-tool validation when available, with local fallback checks.

RPG System File Editor

Overview

Edit RPG Companion App system-definition files safely and consistently. Reuse existing patterns from the target system, keep changes minimal and scoped, and verify behavior after edits.

Core knowledge to use

• Repository layout for system behavior:
  • systems/<system>/system/*.rpgs
  • systems/<system>/system/**/*.rpgs
  • systems/<system>/system/**/*.rpg.json
• RPG Script formula style already used in the codebase:
  • calc and base stats
  • when { ... } branches
  • composable operators (map, filter, add, divide, findFirst, etc.)
• Stat component and formula reference docs when needed:
  • /Users/blastervla/Repositories/RPGCompanionApp/app/docs_output/Stat

Workflow

1. Confirm scope

• Identify system id, target files/folders, and intended behavior change.
• Convert user intent into explicit formula or data-flow requirements before editing.

2. Inspect local patterns first

• Read nearby files in the same feature area before implementing.
• Match naming, branching style, and function composition used by that system.
• Prefer extending current stats/mechanics over introducing new abstractions.

3. Implement in small, composable steps

• Add intermediate stats first, then final outputs.
• Handle null/empty/unknown inputs explicitly.
• Preserve current behavior unless the request requires a behavior change.
• Avoid broad refactors unless explicitly requested.

4. Validate (MCP-first)

• For multi-file edits or renames:
  • run impact_analysis first to scope blast radius.
  • use codemod_batch for renames (dry_run=true first, then apply). Keep default all_or_nothing=true.
  • run symbol_graph and require has_cycles=false.
• Always run build_systems (prefer structured_diagnostics=true when available).
• If behavior changed, run targeted run_tests.
• If MCP is unavailable in the current session:
  • verify config with codex mcp list
  • restart session if server was recently added
  • run local lightweight checks and state limitations.

5. Report

• Summarize changed files and key formula/logic updates.
• Include validation results:
  • impact scope
  • cycle check
  • build result
  • targeted test result (if run)
• Call out assumptions and compatibility decisions.

Guardrails

• Edit only requested systems/files.
• Do not rename existing stat ids unless requested.
• Do not remove backward compatibility without explicit approval.
• Keep formulas deterministic and readable.

Typical requests

• "Update combat logic under systems/<system>/system/combat_system/."
• "Add or modify derived stats in stats.rpgs."
• "Wire a new rules condition into system mechanics/views."