WAIT — Mixed signals — read the receipts

• Last commit 1d ago
• 12 active contributors
• Other licensed
• Tests present
• ⚠ Concentrated ownership — top contributor handles 73% of recent commits
• ⚠ Non-standard license (Other) — review terms
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_{Computed from maintenance signals — commit recency, contributor breadth, bus factor, license, CI, tests}

PKHeX is a C# Windows Forms application that reads, edits, and saves Pokémon save files across all core series games (Gen I–IX). It decodes binary save formats, game-specific memory layouts, and individual Pokémon entity files (.pk*, .ck3, .xk3, .pb7, etc.), allowing users to inspect and modify Pokémon data including stats, moves, ribbons, and game-specific attributes before re-encoding to the original format. Monolithic C# solution with PKHeX.Core as the primary library containing Editing/ (applicators for moves, ribbons, gender, etc.), BattleTemplate/ (Showdown format parsing and export), and numerous game-generation-specific subdirectories. Applicators follow a single-responsibility pattern (BallApplicator.cs, RibbonApplicator.cs, etc.) for modifying Pokémon attributes; BattleTemplate handles import/export of team formats (ShowdownSet, PokepasteTeam).

Pokémon enthusiasts, competitive players, save file managers, and legality checkers who need to inspect and modify save files extracted from cartridges or emulators, verify Pokémon legality, convert between generations, and import/export teams via Pokémon Showdown format.

Production-ready and actively maintained. The codebase is large (11.7 MB C#), well-established with comprehensive format support spanning 25+ years of Pokémon games, and receives regular updates. Built on stable .NET 10 / C# 14 with professional CI/CD (evidenced by .github/ templates and code organization). Appears to be the de facto standard Pokémon save editor in the community.

Single-maintainer risk: repository is kwsch/PKHeX with likely one primary maintainer. Large surface area of game-specific binary format knowledge means format changes in new Pokémon titles require rapid updates or the tool becomes unusable for new saves. Dependency on QRCoder (external) and pokesprite assets (external) means breaking upstream changes could affect functionality. No visible test count in file listing, suggesting limited unit test coverage for complex format parsing logic.

Active development targeting latest Pokémon titles. Recent .NET 10 / C# 14 upgrade visible in Directory.Build.props. BattleTemplate subsystem shows active work on Showdown format parsing (ShowdownParsing.cs, BattleTemplateTeams.cs) and error handling (BattleTemplateParseError.cs). Applicator classes suggest ongoing feature expansion for new game mechanics (MoveShopRecordApplicator, PlusRecordApplicator suggest Pokémon Scarlet/Violet additions).

git clone https://github.com/kwsch/PKHeX.git
cd PKHeX
dotnet restore
dotnet build -c Release

Launch the executable from bin/Release/ or run dotnet run from the main project directory (requires .NET 10 SDK).

Daily commands: Build as above, then execute PKHeX.exe from bin/Release/. GUI-only application; no command-line interface visible. For development, open PKHeX.sln in Visual Studio 2022+ or use dotnet build from command line. Debug configuration available via -c Debug flag.

• PKHeX.Core/Editing/PKM/EntityTemplates.cs — Core Pokémon entity creation and template system—foundational for all save file operations
• PKHeX.Core/Editing/Bulk/Entity/EntityBatchEditor.cs — Main batch editing engine for bulk modifications—critical for the app's mass-edit feature set
• PKHeX.Core/Editing/BattleTemplate/Showdown/ShowdownParsing.cs — Parses Showdown format teams and battle templates—essential for import/export pipeline
• PKHeX.Core/Editing/Applicators/MoveApplicator.cs — Applies and validates legal moves to Pokémon—core to legality checking system
• PKHeX.Core/Editing/Database/TrainerDatabase.cs — Manages trainer and encounter data lookups—backbone of legality verification
• PKHeX.Core/Editing/IPKMView.cs — Abstract interface defining Pokémon view contract—essential abstraction between UI and core logic

Add a new Applicator (e.g., for a new attribute type)

1. Create a new class in PKHeX.Core/Editing/Applicators/ inheriting from or following the pattern of existing applicators like MoveApplicator.cs (PKHeX.Core/Editing/Applicators/YourNewApplicator.cs)
2. Implement attribute validation logic that checks legality constraints against PKM data (PKHeX.Core/Editing/Applicators/YourNewApplicator.cs)
3. Register the applicator in the batch editor or entity suggestion pipeline (PKHeX.Core/Editing/Bulk/Entity/EntityBatchEditor.cs)

Add support for a new team format (e.g., custom JSON format)

1. Create a new parser class in PKHeX.Core/Editing/BattleTemplate/Showdown/ following ShowdownParsing.cs pattern (PKHeX.Core/Editing/BattleTemplate/Showdown/YourFormatParser.cs)
2. Implement parsing logic to convert format into ShowdownSet objects (PKHeX.Core/Editing/BattleTemplate/Showdown/YourFormatParser.cs)
3. Register parser in BattleTemplateTeams.cs to wire into the import pipeline (PKHeX.Core/Editing/BattleTemplate/Showdown/BattleTemplateTeams.cs)
4. Add error handling using BattleTemplateParseError.cs for validation failures (PKHeX.Core/Editing/BattleTemplate/Errors/BattleTemplateParseError.cs)

Add a new batch edit filter or modification type

1. Create a filter class in PKHeX.Core/Editing/Bulk/Entity/ComplexSet/ inheriting from IComplexFilter (PKHeX.Core/Editing/Bulk/Entity/ComplexSet/YourFilter.cs)
2. Implement filter logic to match Pokémon based on your criteria (PKHeX.Core/Editing/Bulk/Entity/ComplexSet/YourFilter.cs)
3. Register filter in EntityBatchEditor.cs and add instruction syntax documentation (PKHeX.Core/Editing/Bulk/Entity/EntityBatchEditor.cs)
4. Add suggestions for auto-completing the filter in BatchModifications.cs (PKHeX.Core/Editing/Bulk/Entity/Suggestion/BatchModifications.cs)

Add a new data lookup table (e.g., new encounter data)

1. Extend TrainerDatabase.cs or create a parallel database service following its patterns (PKHeX.Core/Editing/Database/TrainerDatabase.cs)
2. Populate data using the same binary or structured format as existing records (PKHeX.Core/Editing/Database/TrainerDatabase.cs)
3. Update LegalMoveSource.cs to query new data during legality validation (PKHeX.Core/Editing/PKM/LegalMoveSource.cs)

• C# / .NET — Cross-platform desktop applications with native file I/O and binary manipulation; strong type safety for complex Pokémon data structures
• Showdown Format Parsing — Standard battle format for Pokémon competitive scene; enables easy team import/export and community integration
• Plugin Architecture (IPlugin) — Allows third-party extensions without modifying core; enables community contributions like custom applicators and data sources
• Batch Instruction Language (StringInstruction) — Text-based DSL for bulk edits enables power users to script complex modifications across hundreds of Pokémon efficiently

• Applicators
  • Why: undefined
  • Consequence: undefined

Binary format knowledge: Save files use undocumented binary layouts that vary by generation and Pokémon title; incorrect offset calculations corrupt saves. Generation-specific legality: Pokémon attributes valid in Gen IX may be illegal in Gen V due to format/mechanic differences; applicators must enforce per-generation rules. No enum source control visible: If format specs live in external wikis (Bulbapedia, Serebii) rather than code comments, format changes are easy to miss. QRCoder/pokesprite external dependencies: Must regenerate QR codes and sprite assets when these upstream projects update. Windows Forms only: No web/CLI interface means contributions to add headless API or command-line support would face architectural friction.

• Binary serialization / deserialization of game save formats — Core functionality: PKHeX must parse undocumented binary layouts (offsets, bit-packed fields, checksums, encryption blocks) from 25+ Pokémon save formats; understanding struct marshalling and endianness is essential
• Generation-specific game mechanics and legality constraints — A Pokémon's abilities, moves, and stats are constrained by its generation and game; applicators enforce these rules (e.g., Gen V Pokémon cannot have Megas). Requires knowledge of Pokémon game design across 9 generations
• Applicator pattern for modular attribute editing — PKHeX uses applicators (BallApplicator, RibbonApplicator) as a composition-over-inheritance strategy; each applicator validates and modifies a single attribute atomically, reducing bugs and enabling independent testing
• Pokémon Showdown format parsing and team representation — Showdown format is the human-readable standard for sharing Pokémon teams; ShowdownSet.cs and ShowdownParsing.cs must parse species names, stats, moves, items, and natures from plain text, then validate against game rules
• Interface abstraction for heterogeneous file formats (IBattleTemplate) — PKHeX must support multiple team formats (Showdown, Pokepaste, Battle Videos); IBattleTemplate interface allows pluggable parsers without modifying core logic, enabling extensibility for new formats
• Localization via resource files (.resx) for UI text — PKHeX README lists 8 language translations; .resx files enable compile-time localization without hardcoding strings, crucial for maintaining multiple languages as the codebase evolves
• Checksum validation and corruption detection in binary formats — Save files contain checksums to detect corruption; PKHeX must validate these before parsing and recalculate after modifications, else the edited save becomes unreadable on console

• PokemonROMHacks/pkhex — Mirror/fork of the core PKHeX project; used by ROM hack community for save editing in custom games
• FlagBrew/Checkpoint — Companion tool explicitly mentioned in PKHeX README for extracting unencrypted save files from 3DS/Switch cartridges for PKHeX to read
• j-d-k/JKSM — Alternative save manager for 3DS/Switch; another tool users employ alongside PKHeX to export savedata
• msikma/pokesprite — Upstream sprite asset library that PKHeX uses; contributes shiny sprite collection and UI assets
• codebude/QRCoder — Upstream dependency for QR code generation; used by PKHeX to export Showdown sets as QR codes for mobile import

To work on one of these in Claude Code or Cursor, paste: Implement the "<title>" PR idea from CLAUDE.md, working through the checklist as the task list.

Add comprehensive unit tests for BattleTemplate parsing (Showdown format)

The PKHeX.Core/Editing/BattleTemplate/Showdown directory contains critical parsing logic (ShowdownParsing.cs, ShowdownSet.cs, PokepasteTeam.cs) for importing competitive team formats, but there's no visible test project in the file structure. Given the complexity of parsing multiple Pokémon formats and the BattleTemplateParseError system, comprehensive unit tests would prevent regressions and improve reliability for users importing teams.

• [ ] Create PKHeX.Tests project (if not already present) or identify existing test directory
• [ ] Add unit tests in PKHeX.Tests/Editing/BattleTemplate/Showdown/ for ShowdownParsing.cs covering edge cases (invalid moves, illegal abilities, malformed input)
• [ ] Add tests for ShowdownSet.cs covering serialization/deserialization round-trips
• [ ] Add tests for PokepasteTeam.cs covering multi-Pokémon team parsing
• [ ] Add tests for BattleTemplateParseError error reporting to ensure all error types are caught and reported correctly

Add unit tests for Applicators (Ball, Gender, Move, Ribbon, etc.)

The PKHeX.Core/Editing/Applicators directory contains 13+ critical applicator classes that modify Pokémon data (BallApplicator.cs, GenderApplicator.cs, MoveApplicator.cs, RibbonApplicator.cs, etc.). These are core to the editing functionality but appear to have no dedicated test coverage visible in the repo structure. Applicators are high-risk areas where bugs cause save corruption or illegal Pokémon.

• [ ] Create PKHeX.Tests/Editing/Applicators/ test directory
• [ ] Add unit tests for BallApplicator.cs covering legal ball/species combinations and rejection of illegal combinations
• [ ] Add unit tests for GenderApplicator.cs covering gender ratio calculations and forced-gender species
• [ ] Add unit tests for MoveApplicator.cs and MoveSetApplicator.cs covering move legality, egg moves, and tutor moves per generation
• [ ] Add unit tests for RibbonApplicator.cs covering ribbon availability per generation and game
• [ ] Test HiddenPowerApplicator.cs, MarkingApplicator.cs, and MemoryApplicator.cs for their respective data transformations

Expand batch editing instruction documentation and add parser tests

The PKHeX.Core/Editing/Bulk directory contains a sophisticated batch editing system (StringInstruction.cs, BatchEditingBase.cs, BatchPropertyProvider.cs) that appears powerful but lacks visible documentation on the instruction syntax and available properties. Combined with missing parser tests, this creates a barrier for users and contributors. Adding comprehensive documentation and parser unit tests would improve usability and maintainability.

• [ ] Create PKHeX.Tests/Editing/Bulk/ test directory for batch editing logic
• [ ] Add unit tests for StringInstruction.cs covering instruction parsing, tokenization, and edge cases (invalid syntax, empty instructions)
• [ ] Add tests for BatchEditingBase.cs covering instruction execution, modification results, and error handling
• [ ] Add tests for BatchPropertyProvider.cs covering property name resolution and type conversions for all supported Pokémon properties
• [ ] Document the batch instruction syntax in a new file (e.g., docs/BATCH_EDITING_GUIDE.md) with examples of common operations (IV modification, move changes, stat changes) by game generation

• Add unit tests for ShowdownParsing.cs: The parser handles user input and malformed Showdown format; systematic test coverage for edge cases (invalid species names, out-of-range stats, illegal move combinations) is likely missing.
• Document binary save file format offsets in PKHeX.Core/Gen*/: Create inline code comments or a docs/ folder mapping byte offsets to Pokémon attributes for each generation (e.g., 'Gen V save offset 0x1234 = Pokémon IVs'). Reduces onboarding time for format contributors.
• Implement missing legality checks in applicators: Inspect BattleTemplateParseError.cs for unimplemented error types, then add validation to e.g., GenderApplicator.cs or CatchRateApplicator.cs to catch edge cases (e.g., invalid gender ratios for gender-unknown species in Scarlet/Violet).

PKHeX is a desktop application with moderate security posture. The main concerns are around safe file deserialization, potential expression injection in the batch editing system, and path traversal risks. The codebase lacks visible malicious patterns, but without access to dependency files and full implementation details, comprehensive security assessment is limited. The application should focus on: (1) implementing strict input validation for all file formats, (2) using safe instruction parsing without reflection/dynamic evaluation, (3) preventing path traversal attacks, and (4) maintaining up-to-date dependencies. As a file editor handling user-provided files, secure parsing is critical.

• Medium · Potential Unsafe File Deserialization — PKHeX.Core - Save file parsing modules (not fully visible in provided structure). PKHeX handles multiple file formats for Pokémon save files (.sav, .dsv, .dat, .gci, .bin, .pk*, etc.). Without visible input validation in the provided file structure, there's a risk of arbitrary code execution through malicious save files if deserialization is performed without proper validation. Fix: Implement strict input validation and sanitization for all file format parsers. Use safe deserialization practices with type allowlists. Consider using code signing/verification for loaded files.
• Medium · Expression Injection Risk in Batch Editing — PKHeX.Core/Editing/Bulk/Base/StringInstruction.cs, PKHeX.Core/Editing/Bulk/Entity/ComplexSet/ComplexFilter.cs. The batch editing system (PKHeX.Core/Editing/Bulk) processes user-defined instructions and filters through StringInstruction and ComplexFilter classes. If these instructions are evaluated as expressions without proper sanitization, it could lead to code injection or arbitrary command execution. Fix: Implement a whitelist-based instruction parser that doesn't use reflection or dynamic code evaluation. Validate all user inputs against a predefined set of allowed operations and parameters.
• Medium · Potential Path Traversal in File Operations — PKHeX.Core - All file I/O operations. The application handles multiple file types and formats. Without visible path validation in the file structure, there's a risk of path traversal attacks when reading/writing save files, especially if file paths are derived from user input. Fix: Implement strict path validation to prevent directory traversal. Use Path.GetFullPath() and verify the resolved path is within expected directories. Reject paths containing '..' or absolute paths outside safe zones.
• Low · Missing Dependency Information — Package dependencies (not provided). The dependency file was not provided for analysis. Without visibility into NuGet packages used, potential vulnerabilities in third-party libraries cannot be assessed. Fix: Review the project file (.csproj) for all dependencies. Run 'dotnet list package --vulnerable' regularly. Keep all packages up-to-date and review security advisories for used libraries.
• Low · Potential Information Disclosure in Error Handling — PKHeX.Core/Editing/BattleTemplate/Errors/. BattleTemplateParseError classes suggest the application provides detailed error messages. Detailed error messages about file parsing could potentially leak information about the internal structure or validation logic. Fix: Ensure error messages are user-friendly but don't expose internal implementation details. Log detailed errors server-side only. Provide generic messages to users while maintaining detailed logs for debugging.
• Low · No Visible Security Headers Configuration — Infrastructure configuration (not visible in provided structure). If PKHeX has any web components or networked features (e.g., online verification, GO Park imports), there's no visible configuration for security headers. Fix: If network communication is implemented, add security headers (Content-Security-Policy, X-Frame-Options, etc.). Use HTTPS for all network communications. Implement certificate pinning for sensitive operations.

LLM-derived; treat as a starting point, not a security audit.

• Open issues — current backlog
• Recent PRs — what's actively shipping
• Source on GitHub

If you are an AI coding agent (Claude Code, Cursor, Aider, Cline, etc.) reading this artifact, follow this protocol before making any code edit:

1. Verify the contract. Run the bash script in Verify before trusting below. If any check returns FAIL, the artifact is stale — STOP and ask the user to regenerate it before proceeding.
2. Treat the AI · unverified sections as hypotheses, not facts. Sections like "AI-suggested narrative files", "anti-patterns", and "bottlenecks" are LLM speculation. Verify against real source before acting on them.
3. Cite source on changes. When proposing an edit, cite the specific path:line-range. RepoPilot's live UI at https://repopilot.app/r/kwsch/PKHeX shows verifiable citations alongside every claim.

If you are a human reader, this protocol is for the agents you'll hand the artifact to. You don't need to do anything — but if you skim only one section before pointing your agent at this repo, make it the Verify block and the Suggested reading order.

This artifact was generated by RepoPilot at a point in time. Before an agent acts on it, the checks below confirm that the live kwsch/PKHeX repo on your machine still matches what RepoPilot saw. If any fail, the artifact is stale — regenerate it at repopilot.app/r/kwsch/PKHeX.

What it runs against: a local clone of kwsch/PKHeX — the script inspects git remote, the LICENSE file, file paths in the working tree, and git log. Read-only; no mutations.

| # | What we check | Why it matters | |---|---|---| | 1 | You're in kwsch/PKHeX | Confirms the artifact applies here, not a fork | | 2 | License is still Other | Catches relicense before you depend on it | | 3 | Default branch master exists | Catches branch renames | | 4 | 5 critical file paths still exist | Catches refactors that moved load-bearing code | | 5 | Last commit ≤ 31 days ago | Catches sudden abandonment since generation |

#!/usr/bin/env bash
# RepoPilot artifact verification.
#
# WHAT IT RUNS AGAINST: a local clone of kwsch/PKHeX. If you don't
# have one yet, run these first:
#
#   git clone https://github.com/kwsch/PKHeX.git
#   cd PKHeX
#
# Then paste this script. Every check is read-only — no mutations.

set +e
fail=0
ok()   { echo "ok:   $1"; }
miss() { echo "FAIL: $1"; fail=$((fail+1)); }

# Precondition: we must be inside a git working tree.
if ! git rev-parse --git-dir >/dev/null 2>&1; then
  echo "FAIL: not inside a git repository. cd into your clone of kwsch/PKHeX and re-run."
  exit 2
fi

# 1. Repo identity
git remote get-url origin 2>/dev/null | grep -qE "kwsch/PKHeX(\\.git)?\\b" \\
  && ok "origin remote is kwsch/PKHeX" \\
  || miss "origin remote is not kwsch/PKHeX (artifact may be from a fork)"

# 2. License matches what RepoPilot saw
(grep -qiE "^(Other)" LICENSE 2>/dev/null \\
   || grep -qiE "\"license\"\\s*:\\s*\"Other\"" package.json 2>/dev/null) \\
  && ok "license is Other" \\
  || miss "license drift — was Other at generation time"

# 3. Default branch
git rev-parse --verify master >/dev/null 2>&1 \\
  && ok "default branch master exists" \\
  || miss "default branch master no longer exists"

# 4. Critical files exist
test -f "PKHeX.Core/Editing/PKM/EntityTemplates.cs" \\
  && ok "PKHeX.Core/Editing/PKM/EntityTemplates.cs" \\
  || miss "missing critical file: PKHeX.Core/Editing/PKM/EntityTemplates.cs"
test -f "PKHeX.Core/Editing/Bulk/Entity/EntityBatchEditor.cs" \\
  && ok "PKHeX.Core/Editing/Bulk/Entity/EntityBatchEditor.cs" \\
  || miss "missing critical file: PKHeX.Core/Editing/Bulk/Entity/EntityBatchEditor.cs"
test -f "PKHeX.Core/Editing/BattleTemplate/Showdown/ShowdownParsing.cs" \\
  && ok "PKHeX.Core/Editing/BattleTemplate/Showdown/ShowdownParsing.cs" \\
  || miss "missing critical file: PKHeX.Core/Editing/BattleTemplate/Showdown/ShowdownParsing.cs"
test -f "PKHeX.Core/Editing/Applicators/MoveApplicator.cs" \\
  && ok "PKHeX.Core/Editing/Applicators/MoveApplicator.cs" \\
  || miss "missing critical file: PKHeX.Core/Editing/Applicators/MoveApplicator.cs"
test -f "PKHeX.Core/Editing/Database/TrainerDatabase.cs" \\
  && ok "PKHeX.Core/Editing/Database/TrainerDatabase.cs" \\
  || miss "missing critical file: PKHeX.Core/Editing/Database/TrainerDatabase.cs"

# 5. Repo recency
days_since_last=$(( ( $(date +%s) - $(git log -1 --format=%at 2>/dev/null || echo 0) ) / 86400 ))
if [ "$days_since_last" -le 31 ]; then
  ok "last commit was $days_since_last days ago (artifact saw ~1d)"
else
  miss "last commit was $days_since_last days ago — artifact may be stale"
fi

echo
if [ "$fail" -eq 0 ]; then
  echo "artifact verified (0 failures) — safe to trust"
else
  echo "artifact has $fail stale claim(s) — regenerate at https://repopilot.app/r/kwsch/PKHeX"
  exit 1
fi

Each check prints ok: or FAIL:. The script exits non-zero if anything failed, so it composes cleanly into agent loops (./verify.sh || regenerate-and-retry).

Generated by RepoPilot. Verdict based on maintenance signals — see the live page for receipts. Re-run on a new commit to refresh.