io.github.mrfentmen/yaml-mcp

yaml-mcp

Is the io.github.mrfentmen/yaml-mcp MCP server down? No. It answered initialize and tools/list in the probe of 2026-10-31.

Parse, stringify, and validate YAML locally. No network and no key.

alive probed 2026-11-14 · unchanged since 2026-10-31

2tools

246tokens in Claude Opus 5.5

0.1 %of Claude's 200k window

0.1×the median server

156 msto initialize

30 msto list tools

Run it: npx -y yaml-mcp@1.0.0 (stdio, probed in a container with the network off)
Host: npmjs.com
Reports itself as: yaml-mcp 1.0.0
Capabilities: tools
Instructions: none
Of a 1M window: <0.1 % of a 1M context window
Count: 246 tokens in Claude Opus 5.5, exact, measured 2026-10-17. With the Claude Code prefix mcp__…__ on each tool name: 270. The o200k_base estimate is 125. Counted again when the tool definitions change. Method.
Repository: https://github.com/mrfentmen/yaml-mcp
Registry: active, updated 2026-09-21 · registry entry

Most expensive tools

The Claude column scales the o200k estimate of each tool by this server's ratio of exact to estimate, 1.97×.

Tool	≈ Claude tokens	o200k estimate	Share of this server
parse_yaml	124	63	50 %
to_json	122	62	50 %

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

Servers that mention yaml.

com.ainetcafe/netcafe-devkit · alive
Payload Validator com.gumballtools/payload-validator · alive
io.github.DunkelCloud/toolmesh · needs your URL
Helm MCP io.github.Kubedoll-Heavy-Industries/helm-mcp · not MCP
Penniless Data Utilities io.github.danielarif26/penniless-data-utilities · alive
io.github.haserisa0810-gif/nanami-products · not found
MCP Data Converter io.github.igormilovanovic/data-converter · needs auth
Casper Tools io.github.magiautonomous/casper-tools · no DNS

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.