ScreenSlick MCP Server

Local MCP server for controlling the ScreenSlick browser editor from Codex, Claude Code, Claude Desktop, Cursor, and other MCP clients.

The server runs locally over stdio and opens a localhost bridge at:

ws://127.0.0.1:32117/screenslick-agent

Open ScreenSlick, enter the editor, click Agent, then ask your MCP client to call screenslick_bridge_status.

Motion Studio (npx -y screenslick-mcp studio)

The same package ships the local half of Motion Studio (ScreenSlick → Motion Studio, /studio): a coding agent (Claude Code or Codex) builds Remotion videos on your computer while you watch the live preview and edit every layer on the timeline in the browser.

npx -y screenslick-mcp studio              # workspace in ~/ScreenSlick Studio
npx -y screenslick-mcp studio --dir D:\videos --no-bash
npx -y screenslick-mcp studio --add-dir path/to/your-app   # let the agent read your app's code (remembered)
npx -y screenslick-mcp studio --agent codex   # start the chat with Codex (switch any time in the chat)

It needs Claude Code (claude) or Codex (codex) installed and logged in. With both, the first one found is the default and the chat header switches between them. The command:

• creates or refreshes the workspace: projects/<slug>/ (project.json, layers.json, scenes/*.tsx, assets/, renders/), the screenslick-video-studio skill (in .claude/skills/ and .agents/skills/), CLAUDE.md and AGENTS.md, and the shared runtime in .screenslick/ (managed files are rewritten on every start; projects are never touched);

• owns the bridge on 127.0.0.1:32117. If a ScreenSlick MCP server (the editor tools in a Claude session) already holds the port, the helper asks it to hand the port over (POST /handoff); that server then forwards its calls to the helper, and the editor page reconnects by itself. Servers older than 0.16 can't hand over: restart that Claude session once;

• bundles each open project with esbuild and hot-reloads the page when files change;

• serves project files to the page (range requests) and saves uploads and exports into the project;

• runs the agent headless for the chat panel (claude -p stream-json or codex exec --json, resumed per project; switching agents passes a recap of the chat to the new one), with the screenslick_studio_* MCP tools: status, create/open project, capture frames, contact sheet, media info, transcribe, analyze audio, listen (measure, rank, tags, realness, critique), voice-overs, music (Lyria and the ScreenSlick library), export, focus. Folders added with --add-dir are readable; Claude's edit tools are blocked there (--disallowedTools Edit(...)) and Codex's sandbox only writes inside the workspace;

• keeps voice/music provider keys in ~/.screenslick/studio-keys.json (mode 600, outside the workspace) and strips them from the agent's environment;

• renders locally with Remotion as a fallback (npm install in the workspace on first use).

Only these web origins can use it: https://screenslick.com, https://www.screenslick.com and http://localhost:3005 (add more with --origin <url> or SCREENSLICK_STUDIO_ORIGINS). Requests from any other website are refused. The agent may run shell commands in the workspace unless you pass --no-bash (Codex always has a sandboxed shell; --no-bash turns off its network access instead).

Each agent is one adapter in src/studio/agents/ (how to start the CLI for a turn, how to read its output). To add one, write an adapter next to claude.ts / codex.ts and list it in agents/index.ts.

Update the bundled skill from the ScreenSlick repo with npm run sync:skill.

The current browser app connects on port 32117. Keep that default for the Studio page. A custom --port is passed to the workspace MCP configuration, but does not change the browser's connection address.

Before release, run npm run build, npm run verify:media, npm run verify:bridge-tools, and npm run verify:studio-release. The Studio checks use a temporary workspace and a separate port.

Related MCP server: @uicheck/mcp

Install

No ScreenSlick source checkout is required. Use the npm package from your MCP client:

{
  "mcpServers": {
    "screenslick": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "screenslick-mcp"]
    }
  }
}

If your client uses form fields:

Claude Code

Project-scoped .mcp.json:

{
  "mcpServers": {
    "screenslick": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "screenslick-mcp"]
    }
  }
}

Restart Claude Code, approve the MCP server, then run /mcp to confirm the screenslick server is connected.

Codex CLI

Add a stdio server entry to your Codex config:

[mcp_servers.screenslick]
command = "npx"
args = ["-y", "screenslick-mcp"]
startup_timeout_sec = 10
tool_timeout_sec = 120

Cursor

Create .cursor/mcp.json in a project, or ~/.cursor/mcp.json globally:

{
  "mcpServers": {
    "screenslick": {
      "command": "npx",
      "args": ["-y", "screenslick-mcp"]
    }
  }
}

Available tools

• screenslick_bridge_status

• screenslick_health_check

• screenslick_get_project

• screenslick_analyze_timeline

• screenslick_validate_voiceover_timing

• screenslick_analyze_video_segments

• screenslick_find_clip_candidates

• screenslick_create_clip_collection

• screenslick_get_capabilities

• screenslick_list_voices

• screenslick_list_music

• screenslick_list_sound_effects

• screenslick_list_effects

• screenslick_remove_silences

• screenslick_generate_transcript

• screenslick_generate_script

• screenslick_director_plan

• screenslick_create_demo_video

• screenslick_review_director_draft

• screenslick_generate_voiceover

• screenslick_add_transcript_voiceover_to_timeline

• screenslick_clear_voiceover

• screenslick_replace_voiceover_clips

• screenslick_update_voiceover_clip

• screenslick_move_voiceover_clip

• screenslick_delete_voiceover_clip

• screenslick_regenerate_voiceover_clip

• screenslick_extract_on_screen_captions

• screenslick_merge_on_screen_caption_ocr

• screenslick_create_voiceover_from_on_screen_captions

• screenslick_preview_voiceover

• screenslick_toggle_voiceover

• screenslick_cleanup_timeline

• screenslick_apply_commands

• screenslick_capture_frame

• screenslick_capture_frames

• screenslick_get_source_file

• screenslick_import_voiceover_audio

• screenslick_export_video

Voiceover tools are intentionally editable-first. Agent-created narration should use timeline voiceover clips so the user can see the clips in the sidebar, edit text, move them, delete them, and regenerate audio. screenslick_generate_voiceover defaults to that editable workflow; only pass mode: "full-track" or editable: false when the user explicitly wants one flattened generated track.

Agents that make narration with their own TTS can keep it editable: screenslick_import_voiceover_audio takes one audio file per line (absolute path, startMs, and the spoken text) and adds them as timeline voiceover clips with captions. They move, delete, and export like other clips; to change a line, import a new take.

screenslick_capture_frames samples up to 60 frames per call (explicit times, or a range with fps) and saves each one to a file. screenslick_get_source_file saves the loaded source video to a local file for ffmpeg or other analysis. These three tools need an editor build that supports them; an older editor tab gets a clear "reload the editor" error.

For intro/outro/intermission cards, keep card layers inset instead of flush with the hold edges. Text should usually start a few tenths of a second after the card begins and end before the card ends. Card voiceover should start after the text entrance and leave at least 500ms before a terminal card or final timeline end, especially with premium voices where generated audio can run longer than the requested target.

Environment variables

The bridge is intentionally localhost-only. Remote hosts are rejected.

Verify

1. Start ScreenSlick and open the editor.

2. Click Agent in the editor.

3. Ask the MCP client to call:

   screenslick_bridge_status

Healthy response:

{
  "ok": true,
  "connected": true,
  "port": 32117,
  "path": "/screenslick-agent",
  "session": {
    "hasVideo": true,
    "timelineDuration": 62.63
  }
}

Development

npm install
npm run build
npm run dev

Checks (no ScreenSlick session needed; they use their own port and temp folders):

npm run verify:media
npm run verify:bridge-tools

See ROADMAP.md for the Director Mode plan: reliability, timeline intelligence, voiceover clip control, on-screen caption extraction, and high-level demo-video creation tools.

Use development mode from this repo:

For live source changes:

{
  "mcpServers": {
    "screenslick": {
      "type": "stdio",
      "command": "npx",
      "args": ["tsx", "src/index.ts"],
      "cwd": "/path/to/screenslick-mcp"
    }
  }
}

For testing the built package:

{
  "mcpServers": {
    "screenslick": {
      "type": "stdio",
      "command": "node",
      "args": ["dist/index.js"],
      "cwd": "/path/to/screenslick-mcp"
    }
  }
}

Best-practice notes

• Uses the official MCP TypeScript SDK over stdio.

• Keeps editor bridge traffic on 127.0.0.1.

• Does not require the ScreenSlick source repo on the user's machine.

• Uses structured input schemas for every tool.

• Routes editor actions through ScreenSlick's native editor APIs instead of processing video files directly.

• Health checks include editor bridge compatibility information so stale editor sessions can be diagnosed with a refresh/reconnect instead of mysterious tool failures.

• Provides cleanup tools so agents can clear generated layers before rebuilding a pass while preserving the source video clips.

• Orchestrates editor-native silence removal, local caption generation, and local or confirmed-premium voiceover as part of high-level demo drafts while preserving dry-run safety.

• Applies camera layout polish when the current project has a camera layer, using side-by-side or portrait-overlay layouts based on the target format.

• Runs Director Mode reviews around high-level demo drafts so agents can catch structure, narration, caption, music, SFX, and visual-polish issues before calling an edit done.

• Guides agents to inset intro/outro card text and voiceover inside the card duration so terminal CTA audio does not clip on the final frame.

• Treats premium voice generation as a consent boundary: agents should ask before using premium/Gemini voices because they can consume credits.