Spritecook Generate Sprites

SpriteCook Generate Sprites

Use this skill for still-image generation. Pair it with spritecook-workflow-essentials for credits, manifests, safe downloads, and shared defaults.

Requires: SpriteCook MCP server connected to your editor. Set up with npx spritecook-mcp setup or see spritecook.ai.

For a complete UI screen or cohesive UI system, stop and use spritecook-build-ui-kits instead. The UI-kit workflow creates one coherent concept before extracting reusable controls and states. Keep generate_game_art(mode="ui") for one isolated icon, badge, button, control, divider, frame, or decoration.

Pixel-Art Model Default

• For new pixel-art sprites, use generate_game_art with model="gemini-nano-banana-2.1", pixel=true, and resolution="1K" unless the user requests different settings. For a new base character, use generate_character(model="gemini-nano-banana-2.1", ...).
• Keep explicit user choices and saved preset models. For edits, preserve the source model inherited by the tool unless the user requests a model change.
• Check list_generation_models for current availability and prices. Nano Banana 2.1 retains NB2's base 12 / 18 / 30 credits at 1K / 2K / 4K at release. Source resolution is separate from the requested pixel-art dimensions and does not guarantee an exact final canvas size.
• For transparent sprites, continue using background="transparent"; SpriteCook removes the background after generation. NB2.1 does not produce native alpha transparency.
• Keep the MCP tool's reference limits: style_asset_ids accepts at most 10 IDs, plus the supported reference or edit asset. The provider's 14-image total limit does not increase this tool's argument limit.
• Complete UI kits follow spritecook-build-ui-kits and its own model default.

Tool

generate_game_art

Generate game art assets from a text prompt. Supports both pixel art and detailed/HD styles. Returns a job immediately by default; follow the returned poll.tool and poll.arguments until the assets are ready. Pass wait_seconds only when an explicit bounded wait is useful.

Referenced assets must belong to the user's account. style_asset_ids can be combined with either reference_asset_id or edit_asset_id. Do not combine reference_asset_id and edit_asset_id.

If the user provides local image file paths for these references, use spritecook-upload-assets first and pass the returned asset IDs into the appropriate reference field.

Reference Roles

• Use style_asset_ids for style guide images: ambient style, palette, proportions, rendering, and art-direction context. This is the normal choice when generating a new related asset that should match an existing collection, such as giving three existing buildings as style guides before asking for a new building type. SpriteCook already treats these images as style references; mention them in the prompt only when the user wants a specific trait called out.
• Use reference_asset_id when one specific asset is the source or context for the prompt, such as make a building in a similar style to this one, give me just the door sprite, or use this character as the visual reference.
• Use edit_asset_id when the user wants a direct modification of one existing asset, such as make this roof red, remove the sign, or change the helmet color.

list_generation_models

List available still-image generation models, pixel-art support, reference-image limits, supported quality options, and SpriteCook credit costs per image. Call this when choosing a model or when the user asks what models/costs are currently available.

list_character_workflows

List guided pixel-art character perspectives, default animation ids, source-view/prep requirements, frame counts, and credit estimates.

Perspectives and preset animations:

generate_character

Generate a base pixel-art character with SpriteCook's recommended character settings: 64x64, transparent background, 1K square, tight smart crop, and the perspective-specific character prompt rewrite. Returns a job immediately by default; when complete, the first generated asset is the character_id.

generate_character_animations

Generate preset and/or custom animations for a base character asset. Returns a character-animation run immediately by default; follow the returned polling contract until canonical assets entries are ready.

Custom animations use the custom prompt as the final animation prompt and skip preset prompt enhancement. source_view defaults to front_idle; if another source view needs prep, SpriteCook uses the matching workflow prep dependency for that perspective.

Example custom animation:

{  "label": "Spin Attack",  "prompt": "Spin in place with a quick sword slash, looping cleanly.",  "source_view": "right_walk",  "output_frames": 8}

check_character_animation_run

Check a guided character animation run by id. Returns run status, item statuses, canonical generated assets, prep state, failures, and credits.

Async Result Contract

• Follow the returned poll.tool with its exact poll.arguments; use check_job_status for jobs and check_character_animation_run for character-animation runs.
• Treat operation_id as the generic operation identifier while retaining job_id or run_id for the matching poll tool.
• On success, use each asset's asset_id and sprite_url. Use spritesheet_url only when an animation also provides a spritesheet.
• If a successful response contains warning.code="asset_output_unavailable", execute the supplied warning.recovery tool call instead of searching arbitrary nested URL fields.

Working Style

• Be specific about subject, pose, camera/view angle, and key materials.
• Call list_generation_models when current model names, pixel-art support, quality options, or credit costs matter.
• When the user asks to use a saved preset, use list_presets and get_preset_settings first, then map the returned prompt, style, model, size, color, and reference guidance into generate_game_art.
• Use list_character_workflows, generate_character, and generate_character_animations when the user wants a directly usable animated character set.
• Route menus, HUDs, inventories, dialogs, settings screens, overlays, and other complete UI compositions to spritecook-build-ui-kits.
• Default to pixel art unless the user asks for HD, detailed, smooth, realistic, or high-res output.
• When the user wants the same character or item in multiple outputs, generate one canonical still asset first and reuse that asset ID.
• Use style_asset_ids for follow-up generations that should keep the same visual style, especially when a preset returns settings.reference.styleAssetIds.
• Use reference_asset_id when the prompt depends on one specific visual/context reference asset.
• Use edit_asset_id when directly modifying one existing SpriteCook asset.
• Do not generate multiple independent still variations when the real goal is one consistent character plus later animations.
• Prefer smart_crop_mode="tightest" unless the user explicitly asks for "power_of_2".

Consistency Rules

• For a motion set like idle, walk, attack, or hurt: generate the base character once, then animate that exact asset_id separately for each motion.
• For asset variations that should stay recognizably the same design, prefer edit_asset_id for direct modification or style_asset_ids for style guidance over a brand-new unreferenced generation.
• Only skip a reference when the user explicitly wants different designs to explore.

Pixel Art vs Detailed Art

Pixel art (pixel: true, default):

• Crisp hard edges, no anti-aliasing, visible pixel grid
• Automatic pixel-perfect post-processing for clean grid alignment
• Best for retro games, indie games, and 8-bit/16-bit projects

Detailed/HD art (pixel: false):

• Smooth gradients, fine detail, anti-aliased edges
• Higher fidelity output without pixel grid constraints
• Best for HD 2D games, concept art, and marketing assets

Choose based on the game's art direction. When the user does not specify, default to pixel art.