Face Swap — Swap faces between photos or onto scenes

Tools / Face Swap

Swap Face

Swap a face onto a target image or generate a new scene with the given face. Provide a face source and a target image or prompt.

Returns: Result image URL, downloadable asset, face source, target source, model used, seed, and request metadata

Parameters

face_image *stringURL of the photo containing the face to use as the source.

target_imagestringURL of the image to swap the face onto. The body, pose, and background are preserved.

promptstringScene to generate with the face (e.g. "astronaut on the moon"). Used alone or as guidance with target_image.

modelstringModel to use. Defaults to Nano Banana 2 Edit. Pass a model key or fal.ai endpoint ID to override.

aspect_ratiostringAspect ratio for the output. Only used when generating from prompt (no target_image).

output_formatstringOutput image format. Defaults to jpeg.

seednumberRandom seed for reproducible results.

extra_paramsobjectAdditional model-specific parameters passed directly to the inference API.

Example

Swap face onto another photo

curl -H "Authorization: Bearer $TOOLROUTER_API_KEY" \
  -d '{
  "tool": "face-swap",
  "skill": "swap_face",
  "input": {
    "face_image": "https://example.com/my-face.jpg",
    "target_image": "https://example.com/target-body.jpg"
  }
}' \
  https://api.toolrouter.com/v1/tools/call

Quick Start

MCP (Claude Code)

claude mcp add --transport stdio \
  --env TOOLROUTER_API_KEY=YOUR_API_KEY \
  toolrouter -- npx -y toolrouter-mcp

REST API

curl -H "Authorization: Bearer $TOOLROUTER_API_KEY" \
  -d '{"tool":"face-swap","skill":"swap_face","input":{}}' \
  https://api.toolrouter.com/v1/tools/call

Frequently Asked Questions

What do I need to swap a face?

`swap_face` needs a `face_image` plus either a `target_image` or a text `prompt`.

Can I swap onto a new scene instead of a photo I already have?

Yes. If you only provide a prompt, the tool can generate a scene and place the face into it.

What happens if I provide both a target image and a prompt?

The target image is still used, and the prompt guides how the swap should look in context.

Can I override the default model?

Yes. It defaults to Nano Banana 2 Edit, but you can pass a different `model` if needed.