farworld-labs/remix-add-image

Add Image to Game Workflow

Overview

This skill guides you through generating an AI image and integrating its hosted URL into your game HTML. Prefer MCP generateImage, which now generates and uploads in one step.

Prerequisites

• The game HTML file must already exist (follow the game-creation workflow first if starting from scratch).
• A game must be created on the Remix platform (you need a game ID).
• MCP auth or CLI auth must already be available.

Steps

1. Check for Existing Game ID

IMPORTANT: Do NOT create a new game without checking first.

Use gameId from task context or prior tool results when available.

Otherwise, read the nearest .remix-cli.json. Older projects may still use .remix-mcp.json. If either contains a gameId, reuse it.

Only if none of those sources contain a gameId should you follow the upload-game workflow to create one.

2. Generate the Image

Preferred MCP flow:

generateImage({
  gameId: "<your-game-id>",
  prompt: "a pixel-art treasure chest on a grassy hill",
  fileName: "treasure-chest"
})

The tool returns a hosted asset URL directly. No base64 payload and no separate asset-upload step.

If you are writing direct REST calls instead of using MCP, fetch the exact path and response shape from https://api.remix.gg/docs/json first.

3. Upload as Game Asset

Skip this step when using MCP generateImage; the tool already uploads the generated image and returns the hosted URL.

For uploading non-image assets (audio, 3D models), see the remix-upload-asset skill.

4. Integrate the URL into the Game

Add the asset URL to the game HTML. Size the image to match the game entity it represents -- do not render it at its native resolution. For example, if a treasure chest is a 32x32 tile in your game, draw or display the image at 32x32 regardless of the source image dimensions.

The integration method depends on how the image is used:

As an HTML image element:

<img src="https://returned-asset-url.png" alt="Treasure chest" width="32" height="32" />

As a CSS background:

.game-bg {
  background-image: url("https://returned-asset-url.png");
}

As a JavaScript-loaded image (for canvas games):

const img = new Image();
img.src = "https://returned-asset-url.png";
img.onload = () => {
  // draw at the entity's size, not the image's native size
  ctx.drawImage(img, x, y, entityWidth, entityHeight);
};

Examples

Adding a Background to a Canvas Game

const bg = new Image();
bg.src = "https://uploaded-asset-url/background.png";
bg.onload = () => {
  function draw() {
    ctx.drawImage(bg, 0, 0, canvas.width, canvas.height);
    // draw game objects on top...
    requestAnimationFrame(draw);
  }
  draw();
};

Adding a Sprite Sheet

const spriteSheet = new Image();
spriteSheet.src = "https://uploaded-asset-url/player-sprites.png";
spriteSheet.onload = () => {
  // draw a 32x32 frame from the sprite sheet
  ctx.drawImage(spriteSheet, frameX, frameY, 32, 32, player.x, player.y, 32, 32);
};

Tips

• Be specific in prompts. Include art style, color palette, and context (e.g. "pixel-art 16-bit style red dragon"). No need to specify transparency or background handling -- the server takes care of that.
• Preload images before gameplay. Wait for onload before starting the game loop to avoid flickering or missing assets.
• Repeat for multiple images. Run through steps 2-4 for each image the game needs.