Justcaptions MCP server

Just Captions for agents

Caption videos from Codex, Claude Code, any MCP client, or your terminal. This skill transcribes the speech, makes SRT/VTT/JSON files, and burns TikTok/Reels-style captions into the video. It does one video or a whole folder at a time.

15 animated portable presets follow the Just Captions app style families. Typography and sampled animations can differ from native iOS. Rendering runs on your machine with Pillow and ffmpeg.

Choose a style and copy a task · API docs · OpenAPI · Style catalog

MCP quickstart

Python 3.10+, uv and ffmpeg are required for the packaged MCP/CLI. The plain skill still works with Python 3.9+ and Pillow.

Codex — add to ~/.codex/config.toml:

[mcp_servers.justcaptions]
command = "uvx"
args = ["--from", "https://github.com/SpaceSheepBoy/justcaptions-skill/releases/download/v1.3.1/justcaptions_agent-1.3.1-py3-none-any.whl", "justcaptions-mcp"]
startup_timeout_sec = 120

[mcp_servers.justcaptions_cloud]
url = "https://api.justcaptions.com/mcp"
bearer_token_env_var = "JUSTCAPTIONS_API_KEY"

Claude Code — merge into your project's .mcp.json:

{
  "mcpServers": {
    "justcaptions": {
      "type": "stdio",
      "command": "uvx",
      "args": ["--from", "https://github.com/SpaceSheepBoy/justcaptions-skill/releases/download/v1.3.1/justcaptions_agent-1.3.1-py3-none-any.whl", "justcaptions-mcp"]
    },
    "justcaptions_cloud": {
      "type": "http",
      "url": "https://api.justcaptions.com/mcp",
      "headers": {"Authorization": "Bearer ${JUSTCAPTIONS_API_KEY}"}
    }
  }
}

Set JUSTCAPTIONSAPIKEY, or save a key with the CLI's --signup YOUREMAIL. The local MCP also reads ~/.config/justcaptions/apikey. Never put keys in prompts or commits. For recognition without a key, add "--with", "faster-whisper" before "--from" in the uvx arguments. The offline model downloads on first use.

Ask: “Caption ~/Movies/intro.mp4 with Word Highlight for TikTok. Save MP4, SRT, VTT and JSON in ./captioned/, and preserve the original.”

Shortened. The full README is on GitHub.