Skills

What Are Skills?

Skills are best-practice guides that make AI agents better at game development. Each skill is a folder with a SKILL.md that teaches the agent one discipline: composing a scene, building an FPS controller, generating a character model, setting up multiplayer, debugging a crash. The agent sees each skill’s name and one-line description, and loads the full body only when the situation matches. Skills follow the Agent Skills open standard (<folder>/<skill>/SKILL.md), so the same files work in every agent listed on Every Supported Agent. The library ships inside the summer-engine npm package and is developed in the open at github.com/SummerEngine/summer; the browsable index there is library/skills/README.md.

Quick Start

summer setup installs the whole library for the agent you name, in the same scope as the MCP config:

npx -y summer-engine@latest setup claude-code --yes

Manage skills directly:

summer skills list                         # every skill, one line each
summer skills list --by-domain             # grouped like this page
summer skills info debug                   # one skill's description and body
summer skills install --all --agent cursor # every skill for an agent
summer skills install --recommended --agent codex
summer skills install fps-controller --agent claude-code
summer skills install --all --agent cursor --force   # refresh after an upgrade

--all installs every skill (default for summer setup). --recommended installs the smaller starter subset marked ★ below.
--stable-only skips skills marked preview. Preview means the Summer team has not yet exercised the skill in-engine; the skill’s own text says so.
--force rewrites every installed skill and removes the copies older Summer versions wrote elsewhere (Cursor .mdc rules, OpenCode agents/summer, per-agent folders from 3.1.0).
--scope project installs into the project folder so the skills travel with the game.

Where Skills Live

Most agents read the agentskills.io folder, so one install serves them all:

Agent	Skills folder (user)	Skills folder (project)
Codex, Cursor, Devin Desktop (formerly Windsurf), GitHub Copilot in VS Code, OpenCode, Zed, Kimi Code CLI, Crush, Amp, Factory Droid, Warp, Rovo Dev CLI, Grok Build	`~/.agents/skills` (shared)	`.agents/skills`
Claude Code	`~/.claude/skills`	`.claude/skills`
Antigravity	`~/.gemini/config/skills`	`.agents/skills`
Cline (VS Code)	`~/.cline/skills`	`.cline/skills`
Cline CLI	`~/.cline/skills`	`.cline/skills`
Kilo Code	`~/.kilo/skills`	`.kilo/skills`
GitHub Copilot CLI	`~/.copilot/skills`	`.github/skills`
Kiro	`~/.kiro/skills`	`.kiro/skills`
Goose	`~/.config/agents/skills`	`.agents/skills`
Hermes Agent	`~/.hermes/skills`	`.agents/skills`
Qwen Code	`~/.qwen/skills`	`.qwen/skills`
Qoder CLI	`~/.qoder/skills`	`.qoder/skills`
Mistral Vibe	`~/.vibe/skills`	`.agents/skills`

Claude Desktop, GitHub Copilot in Visual Studio, GitHub Copilot in JetBrains IDEs, Trae, Junie, LM Studio have no skills folder. They get the MCP server only; the model can pull the same guidance in-chat through the summer_get_agent_playbook tool. summer doctor reports when installed skills are older than the CLI. Refresh with summer setup <agent> --yes --force.

Catalog

94 skills grouped by primary domain. ★ = in the recommended set. A skill can belong to several domains; it is listed once, under its first.

2D art

Skill	Use when
character-portrait ★	Generate a single polished character bust for dialogue UI, character select, lore cards, or codex entries. One character, locked composition, VN-style.
concept-art ★	Explore art direction with 3-4 rough concept variants of a character, environment, or prop to pick a vibe before committing to a final asset.
create-asset-sheet	Generate a pack of 2D game assets from one prompt — tile sheet, UI kit, character pack, or biome set — sliced, classified, and saved as one pack ArtAsset.
instantiate-asset-pack	Import a whole create-asset-sheet pack into the scene: groups composites, sorts paint order, emits Sprite2D/Node2D/NinePatchRect ops to lay it out.
pixel-art ★	Generate pixel-art assets — sprites, items, tiles, portraits — at a specific resolution with pixel-perfect grid, limited palette, retro feel.
skybox-panorama	Generate a 360-degree equirectangular sky panorama and wire it as a PanoramaSkyMaterial Sky resource on WorldEnvironment in a 3D scene.
sprite-sheet	Generate animated 2D character sprites laid out as a sprite sheet — walk cycle, attack, idle, death — wired into AnimatedSprite2D / SpriteFrames.
tileable-texture	Generate a seamless tileable texture for walls, floors, or terrain — repeats cleanly on all four edges, wired as a StandardMaterial3D albedo.
ui-graphics	Generate game-UI elements — icons, buttons, panels, frames, HUD widgets, badges — flat design, transparent background, wired via TextureRect/NinePatchRect.
use-widget-asset	Wire a widget slice from a create-asset-sheet pack (panel, button, slider, bar, toggle) into NinePatchRect, TextureProgressBar, or TextureRect via sliceMeta.

3D models

Skill	Use when
character-model ★	Generate a rigged humanoid — player, NPC, enemy, boss — via T-pose reference, user-gated preview, and Meshy auto-rig, wired as CharacterBody3D or Node3D.
environment-kit	Generate a modular environment kit — wall pieces, floor tiles, pillars, doors, arches, corners — snap-together meshes sharing one visual style.
fabricating-assets (preview)	Fabricate meshes with a bpy script in the user’s own Blender (summer_fabricate_3d) — kits with exact dimensions, VFX meshes, post-processing generated models.
organic-model	Generate organic 3D shapes — trees, rocks, mushrooms, coral, plants, vines, crystals — where AI artifacts read as natural irregularity.
prop-model ★	Generate a single static 3D prop — sword, barrel, chest, lantern, throne, statue — one isolated object, no rigging, wired as a MeshInstance3D.
vehicle-model	Generate a hard-surface vehicle — car, spaceship, mech, boat, tank — static mesh with optional detail-texture pass, wired as Vehicle3D or MeshInstance3D.

Agent workflow

Skill	Use when
brainstorming ★	Explore user intent, requirements, and design before implementation — must run before any creative work: features, components, mechanics, behavior.
debugging-game-feel	Debug features that work but feel wrong — floaty jumps, mushy combat, sluggish camera — subjective bugs living in tuning, timing, and feedback layers.
diagnosing-perf-regressions	Find why frame rate, frame time, or load time got worse since a known-good state — regression hunting, not general performance tuning.
dispatching-parallel-agents	Work 2+ independent tasks in parallel when they share no state and have no sequential dependencies.
gameskill	Capture what a game-dev session just learned as a reusable skill (project, user or Summer library) so the next session starts smarter.
godogen-visual-proof-game-generation (preview)	Godogen-style game generation with a visual QC loop — capture frames from the running game, self-verify against the brief, bounded fix rounds, proof clip.
headless-scripting ★	Run a GDScript file against Summer Engine from the shell for operations no MCP tool exposes — navmesh baking, collision shapes, TileSets, re-imports.
investigating-bugs ★	Systematic investigation of any bug, test failure, or unexpected behavior before proposing fixes.
playtesting-a-feature ★	Before claiming a gameplay feature done: actually run the game and walk through the feature. Static diagnostics and type checks do not count.
running-in-the-cloud	Run Summer Engine on a Linux box with no display — install it, launch headless, know when xvfb + software GL are needed, authenticate without a browser.
skill-create	Bootstrap a new Summer library skill (`library/skills/<slug>/` with resource.yaml and SKILL.md), frontmatter, and stub sections.
skill-improve	Upgrade an underperforming Summer skill — run it against a behavioral spec with and without changes via a parallel-eval harness; ship the winner.
skill-test	Lint a Summer skill before commit, audit the whole library, or check a behavioral spec assertion — static structural rules plus behavioral specs.
using-summer	Session bootstrap for Summer projects — establishes how to find and use Summer skills and the summer-engine MCP before any response.
verification-before-completion ★	Run verification commands and confirm output before claiming work complete, fixed, or passing — evidence before assertions, always.
writing-plans	Turn a spec or requirements for a multi-step task into a written implementation plan before touching code.
writing-skills	Create, edit, and verify agent skills — format, structure, testing with subagents, and best practices.

AI and NPCs

Skill	Use when
design-npc ★	Design enemy/NPC/boss/companion behavior — perception, personality, intent, action state machine, telegraphs — outputs a GDScript stub plus node tree.

Animation

Skill	Use when
animation-tree	Design and wire AnimationTree state machines and blend trees so clips respond to gameplay — locomotion blends, attack interrupts, hit reactions.
character-animation-wiring	Wire a rigged, animated character end to end — inspect real clips and bones, locomotion state machine, method-track events, poses, blend shapes, root motion.
facial-and-lipsync	Make a character’s mouth move with a voice-over — phoneme extraction from audio, viseme blendshape mapping, and emotional facial expressions.
generate-motion ★	Attach an animation clip to a rigged character from the curated Meshy motion library — idle, walk, run, attack — wired via AnimationPlayer.
procedural-animation	Runtime bone modification on top of clips — head look-at, foot IK, hand-grabs-prop, additive lean, recoil. Code-and-modifier patterns, not generation.
retarget	Apply existing animation clips from one rigged character to a different rigged character — same library, multiple models, no regeneration.

Asset pipeline

Skill	Use when
asset-strategy ★	Route any ‘I need a [thing]’ asset request to the right specialist skill — disambiguates 2D / 3D / audio / video / VFX / animation pipelines.
lumera-single-image-scene-reconstruction (preview)	Lumera-style single image to editable 3D scene — VLM-parsed object boxes and parametric lights, per-object meshes, HDR probe, .tscn assembly, refinement loop.
skintokens-auto-rigging (preview)	Offline auto-rigging with skin-tokens.cpp (GGML SkinTokens/TokenRig port) — skeleton and skin weights from a static GLB mesh on CPU/Vulkan, into Godot 4.

Audio

Skill	Use when
adaptive-music	Wire music stems to game state — combat/explore/boss/tension crossfades on a shared bus, paired with a state machine and AudioBus structure.
ambient-bed	Generate a long looping location ambience — forest, dungeon, city, spaceship, cave — a looping AudioStreamPlayer on the Ambient bus with a seamless loop.
audio-direction ★	Define the game’s sonic identity — music style, instruments, SFX vocabulary, dynamic music plan — output as an audio bible at .summer/audio-bible.md.
music-track ★	Generate a looped or cinematic music track — loops authored at >=30s with a marked loop point, cinematic tracks at >=60s linear.
sound-effect ★	Generate short SFX one-shots — footsteps, weapon swings, UI clicks, hit impacts — wired as AudioStreamPlayer/2D/3D that auto-frees on finished.
voice-line ★	Generate TTS voice lines — NPC barks, narrator, dialogue — with voice-id sourcing, a character-to-voice decision tree, and multi-line dialogue support.

Character controllers

Skill	Use when
fps-controller ★	Production-quality first-person controller — WASD, mouse look, jump, coyote time, jump buffering, air control, and external-velocity handling.

Debugging

Skill	Use when
debug ★	Disciplined bug/crash/error loop for Summer projects — script errors, console, debugger, hypothesis, fix, verify — before making code or scene changes.

Deployment

Skill	Use when
export-and-ship ★	Assess and prepare a game export: inventory installed templates and targets, validate release assets and config, produce supported builds after approval.
remote-deploy ★	Run or test the game on a real device — phone, tablet, another computer — via the Remote Deploy button, runnable export presets, and on-device debugging.

Editor

Skill	Use when
driving-the-editor-ui (preview)	Drive the editor UI by name: invoke actions, clear blocking dialogs, switch the main screen, read a dock — and route scene work to the scene tools instead.

Gameplay

Skill	Use when
auto-fire-targeting	Design or fix auto-fire weapon targeting (survivors, top-down ARPG, tower defense) — the pending-damage pattern that prevents over-commit and overkill.
celeste-momentum-platforming (preview)	Celeste-style 2D precision platformer movement — momentum running, coyote time, variable jumps, dash, wall jump/slide, climb stamina, pixel corner correction.
design-mechanic ★	Design one game mechanic in detail — input, response, feedback, failure modes, depth, tunables — outputs a design doc, node-graph sketch, GDScript stub.

Level design

Skill	Use when
design-level ★	Design a single level — layout, pacing, encounters, secrets, reward gating — outputs a level design doc and a node-tree skeleton for summer_create_scene.
scene-to-level	Go from a scene reference image or concept art to a playable scene — orchestrates concept, asset pack, terrain, composition, and scene assembly.

Multiplayer

Skill	Use when
host-authoritative-state ★	Design the state layer of a multiplayer game — what the host owns, how clients request changes, and how the host validates and broadcasts.
peer-to-peer-multiplayer ★	Start a multiplayer game from scratch with peer-to-peer host authority — network architecture built top-down, before writing game logic.
setup-multiplayer ★	Add multiplayer to an existing game — LAN/online co-op, PvP, lobbies — via MultiplayerAPI, MultiplayerSpawner, and MultiplayerSynchronizer.

Skill	Use when
navigate-summer ★	When to open a Summer web page or editor surface FOR the user (billing, their games, the scene just built) versus acting through the API, using summer_open.

Performance

Skill	Use when
tune-performance ★	Profile a slow game via summer_get_diagnostics, identify rendering/physics/scripting hotspots, propose fixes with before/after metric expectations.

Rendering and lighting

Skill	Use when
3d-lighting ★	Set up 3D scene lighting — DirectionalLight3D vs Omni vs Spot, WorldEnvironment, sky, shadow tuning, ambient — per current Summer conventions.
art-direction ★	Define the game’s visual style — references, palette, mood, lighting plan, post-processing, do/don’t list — output as an art bible at .summer/art-bible.md.
psx-retro-rendering (preview)	Hardware-informed PlayStation 1 rendering in Godot 4 — low-res output, RGB5 and exact dither, affine textures, vertex snapping, blend modes, fog; limits named.
realtime-wet-surfaces (preview)	Real-time wetness on existing Godot 4 materials without losing their values — value-copying wet shader, geometry-driven wet mask, instance-uniform wet amount.

Runtime

Skill	Use when
agent-playtesting ★ (preview)	Playtest by driving the LIVE game — deterministic launch, frame-stamped probes before/after each action, exact frame steps, scripted or recorded input.

Scenes and project

Skill	Use when
brainstorm-game ★	Turn a vague idea into a buildable plan — genre, scope, core loop, mechanics, art direction — written as a 1-page brief to .summer/GameSoul.md.
browse-templates ★	List available Summer Engine project templates, present the choices, and create a project from the chosen one via summer create.
make-game ★	Orchestration spine for ‘make me a game’: brainstorm, plan, scaffold, mechanics, art, audio, polish, verify, ship — delegates to specialist skills.
new-project ★	Create a fresh blank Summer Engine project — asks one question (project name) and runs summer create empty.
play ★	Run the project in Summer Engine, wait briefly, then report what’s happening — clean run, errors, or warnings.
scene-composition ★	Scene structure conventions — node hierarchy, when to extract sub-scenes, reusable prefab patterns, and instance-versus-add-node decisions.
scene-hierarchy-design (preview)	Structure Summer Engine scenes by access pattern — asset vs live hierarchies, wrapper nodes per operation, sub-scenes for reuse, path-agnostic logic.
scene-scripting ★ (preview)	One GDScript in the live editor (summer_run_script) builds scenes, 2D levels, HUDs and gameplay wiring instead of CRUD chains; verify with diff + screenshot.
spatial-placement ★ (preview)	Place and verify 3D objects with Starcast evidence — inspect, place, starcast, correct, verify; floor, shelf, wall, alcove recipes and overlap repair.
verifying-scenes ★ (preview)	Prove scene work landed — snapshot before, diff + screenshot after (bookmarked viewpoint, labels), live runtime reads during playtests — then claim.
world-building-3d ★ (preview)	Compose, ground, space, and validate 3D scenes with Summer’s four bounded spatial tools — exact paths, one geometric decision at a time, verified.

Scripting

Skill	Use when
gdscript-patterns ★	GDScript conventions — type hints, signals, exports, onready, lifecycle methods, get_node vs $NodePath, naming.

UI

Skill	Use when
ui-basics ★	Build Summer Engine UI — HUDs, menus, health bars, dialogue boxes, Control trees — anchors, containers, responsive layout, theme vs inline styling.

Visual effects

Skill	Use when
game-feel ★	Add juice: hit-flash, trauma-based camera shake, and audio ducking wired so one hit fires all three — for games that feel flat or lack impact.
vfx-dissolve	Dissolve effect — a mesh disintegrating with a glowing burning edge, driven by a noise-threshold ShaderMaterial overriding the target’s material.
vfx-fire ★	Fire effect — animated flames built with a particle shader, GPUParticles3D, and a noise-based color ramp — torches, campfires, candles.
vfx-hit-spark	Hit-spark effect — a one-shot burst of additive billboard particles oriented to a surface normal, fired on impact.
vfx-lightning	Lightning bolt effect — procedural jagged path drawn via ImmediateMesh, glow shader, sparks at endpoints, screen shake.
vfx-magic-glow	Magic-glow effect — a pulsing OmniLight3D plus drifting additive motes plus optional emission shader on the source mesh.
vfx-muzzle-flash ★	Muzzle-flash effect — a one-shot ~80 ms burst at a gun barrel built with a particle one-shot or a flashing quad with a star-burst shader.
vfx-smoke	Smoke effect — a slow-rising column or puff of soft particles built with a noise + density falloff shader on a quad mesh, GPUParticles3D.
vfx-water-ripple	Water-ripple effect — animated normal-distortion ripples on a water plane (or as a Decal) triggered by impacts.

Video

Skill	Use when
animated-loop	Generate a short seamlessly-looping video clip — splash background, animated logo backdrop, idle title-screen footage — wired as a looping VideoStreamPlayer.
cinematic-cutscene ★	Generate a non-interactive cutscene — reference-locked look, a 5-10s image-to-video shot, optional TTS dialogue — wired as a fading VideoStreamPlayer.
trailer-shot	Generate marketing or trailer footage — slow-mo combat, establishing shots, hero beats, splash screens, pitch-deck B-roll — max punch in 5-10 seconds.

For AI Agents

Once installed, the agent discovers skills on its own. Start a session by reading using-summer (the bootstrap skill): it explains how to find the right skill and the right summer_* MCP tool before answering a game-development request. Skills reference the MCP tools and engine value formats (Vector3(0, 10, 0), Color(1, 0.5, 0, 1)).

Contributing a Skill

A skill is one folder in library/skills/<slug>/ with a resource.yaml (id, summary, use_when, facets.domains) and a SKILL.md. Run npm run generate:registry and the tests; the index, the agent manifests and this catalog’s source regenerate from it. The writing-skills skill in the library walks an agent through it.

Next Steps

Every Supported Agent

Config file and skills folder for each agent

CLI Reference

All CLI commands including skills

Need help or have questions? Reach out to our founders at founders@summerengine.com or join our community on Discord for fast responses.

Overview

Summer Games MCP

Setup

CLI

Reference

What Are Skills?

Quick Start

Where Skills Live

Catalog

2D art

3D models

Agent workflow

AI and NPCs

Animation

Asset pipeline

Audio

Character controllers

Debugging

Deployment

Editor

Gameplay

Level design

Multiplayer

Navigation

Performance

Rendering and lighting

Runtime

Scenes and project

Scripting

UI

Visual effects

Video

For AI Agents

Contributing a Skill

Next Steps

Every Supported Agent

CLI Reference

​What Are Skills?

​Quick Start

​Where Skills Live

​Catalog

​2D art

​3D models

​Agent workflow

​AI and NPCs

​Animation

​Asset pipeline

​Audio

​Character controllers

​Debugging

​Deployment

​Editor

​Gameplay

​Level design

​Multiplayer

​Navigation

​Performance

​Rendering and lighting

​Runtime

​Scenes and project

​Scripting

​UI

​Visual effects

​Video

​For AI Agents

​Contributing a Skill

​Next Steps

Every Supported Agent

CLI Reference

What Are Skills?

Quick Start

Where Skills Live

Catalog

2D art

3D models

Agent workflow

AI and NPCs

Animation

Asset pipeline

Audio

Character controllers

Debugging

Deployment

Editor

Gameplay

Level design

Multiplayer

Navigation

Performance

Rendering and lighting

Runtime

Scenes and project

Scripting

UI

Visual effects

Video

For AI Agents

Contributing a Skill

Next Steps