How to Edit Screen Demos with Muse Code and ScreenKite

The short version

Muse Code is Meta's terminal and CI coding agent, built on Muse Spark (default model muse-spark-1.2 in the docs). It is not the consumer Muse personal agent at muse.ai, and it is not a ScreenKite in-app catalog agent.

For screen demos, the useful path is bring-your-own Muse Code pointed at ScreenKite's local MCP + CLI. You get 83 purpose-built editing tools, shaped by tens of thousands of hours of video-editing practice, on a real multi-clip timeline: not computer-use on a finishing NLE, and not Muse AI consumer chores.

One product demo took me an afternoon. Screen Studio was slow and thin on editing, so the clip went to Final Cut, the cuts were fixed, the animations broke, and the clip was exported again. Two tools, two payments, one afternoon gone. Muse Code on ScreenKite's local tools is built to keep that work on one Mac timeline.

What you need

• A Mac running macOS 15 or later (Apple Silicon or Intel)
• ScreenKite installed (account required)
• Muse Code on macOS or Linux per Meta's install docs
• Eligibility for Muse Code / Muse Spark through your Meta / dev.meta.ai account. Meta describes expanded global access; there is no country-by-country list on the pages we checked. Verify during auth. See also authentication and billing. For Muse Code / Model API dollars, check Meta's live pricing and auth pages.

ScreenKite's featured coding agents in product copy stay: Claude Code, ChatGPT Codex, Antigravity, Grok Build, Kimi. Muse Code is an additional BYO path over local MCP/CLI. It does not expand that featured catalog list.

Step 1: Install Muse Code

Per Meta's Muse Code overview (macOS and Linux native binary):

curl -fsSL https://dev.meta.ai/install.sh | sh
muse --version

Meta's AI Developers blog shows the same installer with | bash instead of | sh. Use the command on the live docs page you follow; both invoke the published installer script.

Step 2: Authenticate

From a project directory:

cd /path/to/your/demo-work
muse

On first run, Muse Code asks you to trust the workspace and to authenticate with a browser sign-in or an API key. Reopen sign-in any time with /login. For non-interactive runs, set META_API_KEY (auth docs).

If auth fails for your region or account, stop guessing. Verify eligibility on your Meta / dev.meta.ai account. You can still cut demos in ScreenKite with Claude Code, ChatGPT Codex, Antigravity, Grok Build, or Kimi on the featured path, then add Muse Code as BYO when auth succeeds.

Step 3: Open a ScreenKite demo project

1. Record or open a .skbundle in ScreenKite.
2. Keep the editor window open. ScreenKite exposes 83 MCP tools per open editor window over local HTTP and SSE on loopback (one server per window).
3. Optional: use the toolbar AI Agent control to wire an external agent to that window's MCP server.
4. Or drive the same surface from the CLI: screenkite tool list, screenkite tool describe, screenkite tool call.

Step 4: Connect Muse Code via MCP

Muse Code connects external tools through MCP. Declare servers in the mcp_servers block of your Muse settings (extending docs). Each server uses a transport: stdio (command / args / env) or streamable_http (url / headers).

Point that block at ScreenKite's local MCP endpoint for the open editor window (loopback HTTP/SSE). Copy the connection details from ScreenKite's AI Agent / MCP UI for the window you are editing. Use the live port from that UI, not a guessed number.

Step 5: Ask for confirm:false plans, then commit

On named meaning-changing actions, call with confirm:false first. The tool returns a plan and mutates nothing. A separate call with confirm:true applies it.

Confirm-capable examples that matter for demos:

• edit-timeline → cut
• edit-words → cutSilences, removeWords, removeDeadAir
• markers → generateChapters
• fx → captions/import, captions/patch, voiceover/replace, camera/replace

rm-track, rm-asset, edit-timeline delete, and fx broll_slot/accept take no confirm field. Name the action when you talk about propose-then-commit.

The Core Agent chat panel gates on each tool's riskTier. The agent CLI and third-party MCP clients (including Muse Code) are not gated. Muse Code can send both the propose call and the commit call itself. Ask it to show you the confirm:false plan before you let it send confirm:true if you want a human review step in your workflow.

Example prompt shape:

Open this ScreenKite project. For filler and dead air, run edit-words with confirm:false and show the plan. Do not send confirm:true until I say so. Then export a local MP4 when I approve.

Step 6: Export

Export a local MP4 from ScreenKite. Free tier: unlimited recording, every editing feature; export carries a brand watermark and an animated brand outro. Pro removes the watermark and the outro, adds S3 compatible upload and priority support. One payment. No subscription. AI fee $0.

For Final Cut handoff when you need it, FCPXML is the agent tool export type=fcpxml (FCPXML 1.11 with absolute media paths), the same family of disk-capable export used across the RockieStar editor surface.

How it is built

ScreenKite was AI-native from day one. The UI, the CLI, and MCP clients drive the same 83 tools through the same mutation coordinator. Undo registers like a click. That is the point of BYO Muse Code: a coding agent with MCP editing demos on a purpose-built timeline, not a consumer chat agent and not screenshot computer-use on a finishing suite.

The fastest editor for AI: 83 purpose-built tools, shaped by tens of thousands of hours of video-editing practice, so your agent and you waste less time and money.

Facts (checked 2026-09-15)

Also read

• Muse AI vs Muse Code vs Muse Spark for creators
• Muse Code availability: US, Canada, China, Hong Kong
• Resolve Studio 21.1 MCP is the wrong stack for screen demos
• GPT-6 Astra is not a native editor for screen demos
• How to make a product demo video

Bottom line

Install Muse Code from Meta's docs, authenticate, point mcp_servers at ScreenKite's local MCP, and cut demos with confirm:false plans first. Muse Code stays BYO. Featured ScreenKite agents stay Claude Code, ChatGPT Codex, Antigravity, Grok Build, and Kimi.

Download ScreenKite. Free to start. Pay once to own.