Connect an agent

1. Open Settings → Developer → Edit Config.
2. Add the sfx entry below. Use full paths: ~ doesn't work in this file, so write out /Users/you/….
3. Quit and reopen Claude Desktop.

{
  "mcpServers": {
    "sfx": {
      "command": "node",
      "args": ["/Users/you/sfxforge/src/server.js"],
      "env": { "SFX_DIR": "/Users/you/galacticsmashbros/assets/sfx" }
    }
  }
}

If the file already has other servers, add "sfx": {…} inside the existing mcpServers block rather than pasting a second one.

The Claude API's built-in MCP connection only reaches servers on a public https:// address, so it can't reach this local server. The repo includes a small bridge instead. It starts the server from Python, offers its tools to Claude, and passes results back, including the preview images.

pip install anthropic mcp
export ANTHROPIC_API_KEY=…
SFX_DIR=~/galacticsmashbros/assets/sfx \
  python ~/sfxforge/examples/agents/claude_api_bridge.py \
  "Make a light and heavy punch and a 40 second boss track, then export a pack"

To use it inside an orchestrator, import it and give your sound-design agent a task:

# a "sound designer" child agent
import asyncio, os, sys
sys.path.insert(0, os.path.expanduser("~/sfxforge/examples/agents"))
os.environ["SFX_DIR"] = os.path.expanduser("~/galacticsmashbros/assets/sfx")
os.environ["SFX_TOOLS"] = "generate_sound,variations,generate_music,remix_music,render_sound,export_pack"
import claude_api_bridge as sfx

asyncio.run(sfx.run("Give the dash move a whooshier sound and export the pack"))

SFX_TOOLS is an allowlist. Leave out delete_sound or play_sound for agents that shouldn't use them. Other models that support tool calling (MiniMax, DeepSeek and so on) work the same way: only the model call changes. Models that can't read images still get the numbers but won't see the waveform previews.

WebMCP is a new browser standard: a web page registers tools that agents in the browser can call directly, instead of clicking around the screen. When the editor is open in a browser that supports it, it registers 12 tools and shows a green WEBMCP · 12 TOOLS badge in its top bar. The agent drives the live editor, so you watch every change happen and each step lands in the history strip.

1. Use Chrome 149 to 162. This site is registered for Chrome's WebMCP origin trial (until 30 March 2027), so it works with no setup. On other origins, such as a local copy, turn it on at chrome://flags/#enable-webmcp-testing.
2. Open the editor and check for the badge in the top bar.
3. Use an agent that speaks WebMCP. Today that mostly means extensions, such as Chrome's Model Context Tool Inspector, which lists the tools and can run them by hand or with Gemini.
4. Click the page once before asking for sound. Browsers keep audio off until you interact with the page.

Agents that run scripts on the page, such as browser-automation agents, can call the same tools without WebMCP through window.sfxForge:

window.sfxForge.tools                       // names, descriptions, input schemas
await window.sfxForge.call('sfx_compose_music', { style: 'boss', seconds: 40 })
await window.sfxForge.call('sfx_remix_music', { parts: ['drums'] })

Building your own WebMCP client? In Chrome 154 and earlier, executeTool() takes the tool object from getTools() and the arguments as a JSON string, for example executeTool(tool, JSON.stringify(args)). Plain objects are accepted from Chrome 155.

WebMCP is in an early Chrome origin trial and the API is still changing, so treat this route as a preview. The browser tools work on the sound in front of you and return numbers rather than audio or images. For building a whole pack into your game folder, routes A–C are the dependable choice. Inside a Claude artifact the page runs in a sandboxed frame, so WebMCP is only available on this site.