Spritecook Upload Assets

SpriteCook Upload Assets

Use this skill when a local image file should become a reusable SpriteCook asset_id.

Pair it with spritecook-workflow-essentials for credential safety, manifests, and downstream asset reuse.

Preferred Flow

1. Inspect the local file path without printing file bytes.
2. Determine file_name, MIME content_type, optional size_bytes, and whether pixel should be true.
3. Call create_asset_upload(file_name=..., content_type=..., pixel=..., size_bytes=...).
4. Upload the file bytes to the returned upload_url with HTTP PUT and the returned headers.
5. Call finalize_asset_upload(upload_token=...).
6. Use the returned asset_id in the next SpriteCook tool.

The upload URL and token are short-lived secrets. Do not print them in user-facing prose, save them to project files, or include them in manifests.

PowerShell Pattern

On Windows, upload without printing bytes:

Invoke-WebRequest -Method Put -Uri $uploadUrl -InFile $path -ContentType $contentType | Out-Null

Use variables for $uploadUrl, $path, and $contentType; do not echo them if they include the upload token.

When To Use Inline Import

Use import_asset(image=...) only when the image is already a small data URL or base64 value that can be passed directly without logging it.

Do not use shell commands that print base64 to the terminal. If encoding is necessary, store the value in memory or a private variable and pass it directly to the MCP tool.

Reusing Uploaded Assets

• Use reference_asset_id when the uploaded asset is one specific source or context image.
• Use edit_asset_id only when the uploaded asset is the one image being directly modified.
• Use style_asset_ids on generate_game_art when uploaded assets are ambient style guides; pass up to 10 IDs.
• Use style_asset_id on generate_tileset for one tileset style guide image.
• Use asset_id on animate_game_art when the uploaded asset is the source to animate.

Save the returned asset_id and a local file hash in the project manifest when the workspace is writable.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: SpriteCook
• Source: SpriteCook/skills
• License: MIT

Install and usage instructions live in the source repository linked above.