Screenslick

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.

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:

Field	Value
Name	screenslick
Transport	stdio
Command	npx
Arguments	-y, screenslick-mcp

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_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.

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

Variable	Default	Purpose
SCREEN_SLICK_AGENT_PORT	32117	Local bridge port
SCREEN_SLICK_AGENT_HOST	127.0.0.1	Must remain localhost
SCREEN_SLICK_AGENT_LOG	package .tmp/screenslick-agent-mcp.log	Debug log path

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

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.