io.github.leogaudin/opencaptions

OpenCaptions

Is the OpenCaptions MCP server down? No. It answered initialize and tools/list in the probe of 2026-11-14.

Animated word-by-word captions for your videos, on your computer or your own OpenCaptions server

alive probed 2026-11-14

9tools

8.8ktokens in Claude Opus 5.5

4.4 %of Claude's 200k window

3.5×the median server

295 msto initialize

7 msto list tools

Run it: npx -y opencaptions@1.3.2 (stdio, probed in a container with the network off)
Host: npmjs.com
Reports itself as: opencaptions 1.3.2
Capabilities: tools
Instructions: 188 characters
Of a 1M window: 0.9 % of a 1M context window
Count: 8.8k tokens in Claude Opus 5.5, exact, measured 2026-11-11. With the Claude Code prefix mcp__…__ on each tool name: 8.9k. The o200k_base estimate is 5.2k. Counted again when the tool definitions change. Method.
Repository: https://github.com/leogaudin/opencaptions
Website: https://docs.opencaptions.app/guides/agents/
Registry: active, updated 2026-11-13 · registry entry

Most expensive tools

The Claude column scales the o200k estimate of each tool by this server's ratio of exact to estimate, 1.68×.

Tool	≈ Claude tokens	o200k estimate	Share of this server
caption_video	4 046	2 409	46 %
set_style	3 515	2 093	40 %
save_video	417	248	5 %
fix_words	291	173	3 %
export_subtitles	186	111	2 %

Other registry entries on npmjs.com, the ones next to this name; all of them.

Servers that mention animated or captions.

The result of the latest probe, the tool count and the token cost. The feed has an entry for every probe that changed them.

Stops answering, comes back, tool set or cost changes. One confirmation mail first, a stop link in every mail.