Rast Creator Tools

Rast Creator Tools — remote MCP server

Free, no-auth remote MCP server with deterministic tools for short-form video creators: Reels / TikTok / Shorts safe zones, caption placement checks, video bitrate & file-size math, SRT subtitle validation and platform export settings. It exposes the free creator tools of rastcreative.com/en/tools/ to AI assistants (Claude, ChatGPT, Gemini, Cursor, VS Code, …).

Endpoint (Streamable HTTP):

https://rast-creator-tools-mcp.studio-c25.workers.dev/v1/mcp

Health: https://rast-creator-tools-mcp.studio-c25.workers.dev/health · Privacy: https://rastcreative.com/en/tools/creator-tools-mcp-privacy/ · Terms: https://rastcreative.com/en/tools/creator-tools-mcp-terms/

• No API key, no sign-up, no user data stored, no logging, no outbound requests.
• Stateless and deterministic; all tools are read-only (readOnlyHint: true, idempotentHint: true, openWorldHint: false).
• Every result includes a source link to the matching rastcreative.com tool page.

Tools

Tool	What it does
get_safe_zone	Unsafe margins (px + %), safe rectangle and right-side button column for reels, tiktok, shorts, story or all, scaled to any frame size
check_text_position	Is a text box inside the safe zone? Which UI element covers it (top bar, caption area, buttons, edges, Reels comment sticker)? Nearest safe position
calculate_bitrate	File size from duration + bitrate, or the max bitrate that fits a size limit; reference bitrates per platform/resolution/fps; 2-pass ffmpeg command
validate_srt	SRT/WebVTT check: overlaps, gaps, ordering, reading speed (CPS), line length/count, durations, mojibake — optionally returns a fixed SRT
export_settings	Codec, container, resolution, fps, bitrate, colour and audio settings with official spec links for YouTube (SDR/HDR), Vimeo, Instagram Reels, TikTok and a ProRes master

Connect

Claude (claude.ai / Desktop) → Settings → Connectors → Add custom connector → paste the endpoint URL.

ChatGPT (developer mode) → Settings → Connectors → Create → endpoint URL, authentication None.

Gemini Apps Developer Mode → https://gemini.google.com/devmode → Create new → endpoint URL, authentication none.

Cursor / VS Code / any client with remote MCP support:

{
  "mcpServers": {
    "rast-creator-tools": { "url": "https://rast-creator-tools-mcp.studio-c25.workers.dev/v1/mcp" }
  }
}

stdio-only clients (via mcp-remote):

{
  "mcpServers": {
    "rast-creator-tools": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://rast-creator-tools-mcp.studio-c25.workers.dev/v1/mcp"]
    }
  }
}

Run locally over stdio (no network needed):

npm install && npm run build:stdio
node dist/stdio.mjs        # or: docker build -t rast-creator-tools . && docker run -i --rm rast-creator-tools

Example prompts

• What is the safe zone for a 1080x1920 TikTok video?
• Is a caption box at y = 1550 px on a 1080x1920 frame covered by the Reels interface?
• How big will a 3-minute 4K 30 fps YouTube export at 45 Mbps be?
• What bitrate do I need to keep a 90-second 1080p video under 100 MB?
• Check this SRT for overlaps, reading speed and broken characters: (paste subtitles)
• What export settings should I use for an HDR YouTube upload?

Raw request

curl -s -X POST https://rast-creator-tools-mcp.studio-c25.workers.dev/v1/mcp \
  -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"get_safe_zone","arguments":{"platform":"reels"}}}'

Endpoints

Path	Purpose
POST /v1/mcp (alias /mcp)	MCP JSON-RPC over Streamable HTTP, stateless (no Mcp-Session-Id), JSON responses. GET → 405
GET /health	{"status":"ok",...}
GET /	Short landing JSON (endpoint, tools, data policy)
GET /.well-known/google-connected-apps	Domain-verification JSON for Google Connected Apps (404 until configured)

Develop & self-host

TypeScript, MCP TypeScript SDK, Cloudflare Workers (free plan is enough).

npm install
npm test              # vitest (tools + HTTP/MCP round trips)
npm run typecheck
npm run dev           # wrangler dev → http://127.0.0.1:8787
npm run smoke         # health + initialize + tools/list + tools/call over real HTTP
npx wrangler deploy   # → https://rast-creator-tools-mcp.<your-subdomain>.workers.dev

src/index.ts      Worker router (/v1/mcp, /health, /, /.well-known)
src/server.ts     McpServer, instructions, tool schemas + annotations
src/tools/*.ts    pure, deterministic tool logic
src/data/         safe-zone and export-spec data (from rastcreative.com)
test/             vitest
docs/             Google Connected Apps registration notes

More free tools

Browser versions of these tools and more: rastcreative.com/en/tools/ — by Rast Creative Studio.

License

MIT © Rast Creative Studio