Balatro Mod Development

Create and debug Balatro mods with Steamodded, Lovely, and SMODS.

Quick Agent Selection

When researching or writing code, spawn the right sub-agent via the Task tool:

<!-- Agent table: also in references/sub-agents.md and commands/help.md -->

| Need to find... | Use agent | Model | Search boundary | |-----------------|-----------|-------|----------------| | Game function implementation | game-source-researcher | sonnet | Balatro_src/ only | | SMODS API usage/hooks | smods-api-researcher | sonnet | smods/ only | | How other mods do X | mod-pattern-researcher | sonnet | Mods/ folder only | | Lovely patch syntax | lovely-patch-researcher | sonnet | lovely files only | | Project architecture/exploration | project-explorer | sonnet | Current project only | | Write code per plan | code-writer | sonnet | Current project only | | Run temp script for data | script-runner | haiku | N/A (execution) | | Review code for correctness | code-reviewer | opus | Current project only | | Synthesize multi-source research | research-analyst | opus | Current project only | | Plan complex implementation | strategic-planner | opus | Current project only | | Inspect runtime logs, dumps, compat | debug-inspector | sonnet | Lovely logs/dumps only |

The main agent handles directly: User interaction, small edits (<20 lines), presenting results.

Parallel: When researching DIFFERENT sources — spawn multiple Task calls in one message Sequential: When second query depends on first result

See references/sub-agents.md for the 5-phase workflow, iterative retrieval protocol, and delegation rules.

Repo Type Awareness

Auto-detection: Compare mod manifest author with git remote username.

# Get git remote username
git_user=$(git remote get-url origin 2>/dev/null | sed -E 's|.*[:/]([^/]+)/[^/]+\.git$|\1|' | tr '[:upper:]' '[:lower:]')

# Get mod author from manifest (first author, lowercase)
mod_author=$(jq -r '.author[0] // .author // ""' *.json 2>/dev/null | head -1 | tr '[:upper:]' '[:lower:]')

# Compare: match = own, no match = fork
[[ "$git_user" == "$mod_author" ]] && echo "own" || echo "fork"

| Type | Detection | Implications | |------|-----------|--------------| | new | Empty repo (no files) | Full docs, Logger.lua, localization | | own | Author matches git user | Full docs, standardize structure | | fork | Author differs from git user | Minimal changes, temp logs only |

File Convention

| File | Purpose | Git | |------|---------|-----| | AGENTS.md | Mod structure, functions, dependencies, constraints, Quick Reference (for AI agents) | ignored | | mod.config.json | File lists for sync/release scripts | ignored | | docs/knowledge-base.md | Issues & lessons learned | ignored |

AGENTS.md Purpose: Enable seamless handover between agents. Another agent should quickly understand mod structure, functions, dependencies, constraints, and repo type from a single file.

File Placement Rules

Only these .md files belong in root:

• README.md, README_zh.md
• CHANGELOG.md, CHANGELOG_zh.md
• AGENTS.md
• LICENSE.md

ALL other .md files MUST go in docs/

External References (No Symlinks Needed)

Access reference code directly via absolute paths. No setup required.

Source Locations (macOS)

| Resource | Path | |----------|------| | Game Source (desktop) | ~/Development/GitWorkspace/Balatro_src/desktop/ | | Game Source (mobile) | ~/Development/GitWorkspace/Balatro_src/ios_plus/ | | Steamodded Source | ~/Development/GitWorkspace/smods/src/ | | Steamodded Lovely | ~/Development/GitWorkspace/smods/lovely/ | | Lovely Docs | ~/Development/GitWorkspace/lovely-injector/ | | Installed Mods | ~/Library/Application Support/Balatro/Mods/ | | Lovely Logs | ~/Library/Application Support/Balatro/Mods/lovely/log/ |

Source Locations (Windows)

| Resource | Path | |----------|------| | Game Source | Varies by setup | | Installed Mods | %APPDATA%/Balatro/Mods/ | | Lovely Logs | %APPDATA%/Balatro/Mods/lovely/log/ |

Pattern References

Read these files for specific topics:

| Topic | Reference File | |-------|---------------| | Lovely.toml syntax | patterns/lovely-patches.md | | SMODS hooks, config, localization | patterns/smods-api.md | | Desktop vs mobile differences | patterns/mobile-compat.md | | UIBox, CardArea, draw order | patterns/ui-system.md | | Game source file map + search tips | references/game-files.md | | G.GAME, G.STATES, G.P_* globals | references/globals.md | | Lua/LuaJIT pitfalls, common mod bugs | references/lua-gotchas.md |

New Mod Setup (type: new)

Templates in ${CLAUDE_PLUGIN_ROOT}/templates/ folder:

| File | Purpose | |------|---------| | agents-md-template.md | AGENTS.md template for standard mods | | agents-texture-pack-template.md | AGENTS.md for Malverk texture packs | | mod-config-template.json | Script configuration | | gitignore-template | Standard .gitignore | | logger-template.lua | Centralized logging utility |

Meta Files:

| File | Purpose | |------|---------| | mod-json-template.json | SMODS mod manifest ({ModName}.json) | | manifest-json-template.json | Thunderstore manifest |

User Docs in templates/docs/:

| File | Purpose | |------|---------| | description-template.md | Concise README for docs/ | | NEXUSMODS_DESCRIPTION-template.txt | BBCode for NexusMods | | knowledge-base-template.md | Issues & lessons learned |

Basic Mod Structure (new repos):

{ModName}/
├── main.lua                 # Entry point, mod registration
├── config.lua               # Config defaults (optional)
├── lovely.toml              # Lovely patches (if needed)
├── {ModName}.json           # SMODS mod manifest
├── manifest.json            # Thunderstore manifest
├── mod.config.json          # Script configuration
├── Utils/
│   └── Logger.lua           # Centralized logging
├── localization/
│   ├── en-us.lua            # English (required)
│   └── zh_CN.lua            # Chinese
├── assets/                  # Sprites, shaders
├── scripts/                 # Utility scripts
└── docs/                    # Documentation

Available Commands (16 total — plugin-bundled, auto-loaded)

• /balatro-mod-dev:familiar - Get familiar with this mod (reads AGENTS.md, maps architecture)
• /balatro-mod-dev:init - Initialize new mod
• /balatro-mod-dev:sync-mod - Start sync with watch mode (run once at start)
• /balatro-mod-dev:bump-version [patch|minor|major] - Increment version, update changelogs
• /balatro-mod-dev:release - Create release packages (auto-detects version from manifests)
• /balatro-mod-dev:fix-sprites <directory> [--preview] - Fix grey borders on sprites
• /balatro-mod-dev:refactor [focus-area] - Review code for redundancy, outdated fallbacks, modularization
• /balatro-mod-dev:debug - Verify fix by checking Lovely logs (auto-detects mod key from repo)
• /balatro-mod-dev:test [scenario] - Run test scenarios and verify mod behavior via Lovely logs
• /balatro-mod-dev:draft-pr - Draft PR message (for forks)
• /balatro-mod-dev:check - Audits project health, scaffolds missing rules
• /balatro-mod-dev:update-docs - Review all docs for accuracy, staleness, duplication, verbosity
• /balatro-mod-dev:update-plugin - Update plugin based on new knowledge
• /balatro-mod-dev:knowledge - Review session work, capture discoveries
• /balatro-mod-dev:compact - Evaluate whether to compact context now
• /balatro-mod-dev:help - List all available commands and agents

Sub-agents (11 total — plugin-bundled)

• game-source-researcher - Find game functions and injection points (sonnet)
• smods-api-researcher - Find SMODS API patterns and usage (sonnet)
• mod-pattern-researcher - Find how other mods implement features (sonnet)
• lovely-patch-researcher - Find Lovely patch syntax and examples (sonnet)
• project-explorer - Extensive codebase exploration (sonnet)
• code-writer - Execute implementation plans, write code (sonnet)
• script-runner - Run temp scripts and return results (haiku)
• code-reviewer - Review code for correctness and edge cases (opus)
• research-analyst - Synthesize findings from multiple researchers (opus)
• strategic-planner - Plan implementation strategy for complex features (opus)
• debug-inspector - Inspect runtime logs, dumps, mod compatibility (sonnet)

Logging

For new/my repos:

Use Utils/Logger.lua (from ${CLAUDE_PLUGIN_ROOT}/templates/logger-template.lua):

local Logger = require("Utils.Logger")
local log = Logger.create("ModuleName")
log("info", "Initialized")
log("error", "Failed: " .. err)

For forks/others' repos:

Use temp logs only (remove before PR):

pcall(print, "[Debug] checkpoint: " .. tostring(var))

Utility Scripts

| Script | Purpose | |--------|---------| | ${CLAUDE_PLUGIN_ROOT}/scripts/sync_to_mods.template.sh | Sync mod files to game's Mods folder | | ${CLAUDE_PLUGIN_ROOT}/scripts/create_release.template.sh | Create release packages | | ${CLAUDE_PLUGIN_ROOT}/scripts/fix_transparent_pixels.py | Fix grey borders on sprites |

Workflow: Debugging

1. Check references/lua-gotchas.md for known pitfalls (FFI cdata, nil scoping, boolean normalization)
2. Check platform (desktop vs mobile)
3. Search game source for function
4. Check other mods for implementations
5. Add logs (Logger.lua for own, temp for fork)
6. Check Lovely logs
7. If fix fails 3+ times: Invoke research-analyst (opus) to synthesize all debugging context

Workflow: Update User Docs

When user says "update all user docs":

1. Review ALL files: README(_zh).md, CHANGELOG(_zh).md
2. Review docs/: description.md, NEXUSMODS_DESCRIPTION.txt
3. Update version in {ModName}.json, manifest.json
4. Ensure EN/ZH consistency