Breakage Calendar MCP server

check docker:postgres:latest pypi:celery==5.4.0 pypi:langsmith runner:macos-14 → postgres:latest is due to move to 19 on 19 November 2026: HITS, tested fix (pin postgres:18; we ran it on 13 November). The macOS 14 runner was retired on 2 November: HITS. langsmith's evaluator sends gpt-4o by default, and OpenAI removes the snapshots gpt-4o points to on 14 January 2027: MAY HIT. Celery beat paused for the repeated hour in our tests when US clocks went back on 1 November: MAY HIT, tested fix. That is this server's real answer on 13 November 2026 (five dates in all), from the Breakage Calendar: 65 dated upstream changes that break working software, each with the check that finds it and, for 29 of them, a fix we ran ourselves.

An MCP server (and a command) for coding agents that upgrade, pin or deploy a project. It answers: which dated breaks hit this repository or this dependency list, and what is the tested fix? No key, no account, no dependencies.

Install

Node.js 18.17 or later. Every client starts the same command:

npx -y github:CyberNative-AI/breakage-calendar-mcp

Claude Code (from the project folder, so check_repository can read it):

claude mcp add breakage-calendar -- npx -y github:CyberNative-AI/breakage-calendar-mcp

Claude Desktop, Cursor, Windsurf, Cline and other clients with an mcpServers JSON file:

{
  "mcpServers": {
    "breakage-calendar": {
      "command": "npx",
      "args": ["-y", "github:CyberNative-AI/breakage-calendar-mcp"]
    }
  }
}

VS Code (.vscode/mcp.json):

{
  "servers": {
    "breakage-calendar": { "type": "stdio", "command": "npx", "args": ["-y", "github:CyberNative-AI/breakage-calendar-mcp"] }
  }
}

To pin a release, write github:CyberNative-AI/breakage-calendar-mcp#v0.1.0.

Without MCP, the same answers on the command line:

npx -y github:CyberNative-AI/breakage-calendar-mcp check docker:postgres:latest pypi:celery==5.4.0
npx -y github:CyberNative-AI/breakage-calendar-mcp repo .
npx -y github:CyberNative-AI/breakage-calendar-mcp upcoming 90

Related MCP server: driftwatch-mcp

Tools

Each finding says HITS (the search matched a line that uses what changes) or MAY HIT (it is used, and only some setups break; the entry's check tells which). Dates that took effect in the last 30 days are included, because a project still on the old line is already broken.

What it adds to endoflife.date and a web search

endoflife.date tells an agent when a version stops getting updates. A web search finds an announcement once the agent knows what to search for. Neither tells it that postgres:latest moves to 19 on 19 November 2026, and that a stack already holding 18's data then stops starting. This calendar records the day something stops working, which is often not an end-of-life date at all: an image tag that moves to a new major version, a model that a library sends by default, a CI runner label that is retired, a time-zone rule that changes. For each date it gives:

• the search that finds it in a repository's files, run for you; for dates a repository cannot show (a running server, a clock, a certificate), the check to run where it lives;

• who is and is not affected, from our own tests where we ran them;

• the fix: one we ran, with the day we ran it, or a guide, or, where we have neither, the vendor's notice and the words "no tested fix yet";

• the vendor's own notices, each with the day we last read it.

On 13 November 2026 that was 65 dates: 49 with a repository search, and 29 with a fix we ran. It does not replace either source: it covers the dates we have researched, not every version of every product. For a product's support dates, ask endoflife.date.

What it reads and sends

• It fetches two files, by GET with no body: https://cybernative.ai/breakage-calendar/entries.json and https://cybernative.ai/breakage-calendar/check/signatures.json, with the user agent breakage-calendar-mcp/0.1.0 (+https://github.com/CyberNative-AI/breakage-calendar-mcp), and refuses redirects. It keeps them in memory and asks again after an hour (with If-None-Match). Like any web request, these show our server your IP address and the time. Nothing from your project, dependency list or files is sent.

• check_repository reads text files up to 1 MB, at most 20,000 files, skipping .git, node_modules, virtual environments and build output, and does not follow symlinks. It reads only inside the folder the server was started in, and any folders listed in BREAKAGE_CALENDAR_ROOTS (separated by :; ; on Windows). Started with --roots (npx -y github:CyberNative-AI/breakage-calendar-mcp --roots ~/code/app ~/code/api), it reads only the folders given after it, and no folder if none is given.

• The searches come from the calendar files, so they run in a separate thread with a 2-minute deadline and a 256 MB heap limit.

• If cybernative.ai cannot be reached, the tools say so; after a first successful read they keep answering from that copy and say it is stale. There is no bundled copy of the dates.

Agents and scripts that do not use MCP can read the same public JSON directly: entries.json (every date) and check/signatures.json (the searches).

Limits

• A search finds what a repository's files show. Dates that depend on a server, a certificate, a clock or a browser are listed as such, with their own check.

• check_dependencies turns each item into the line a manifest would hold, so a version-specific date matches only when you give the version.

• MAY HIT means "read the check": in our tests only some versions or settings broke.

Development

npm test

No dependencies. src/match.js is a byte copy of the matcher that the in-browser check runs, so both give the same answer for the same files.

Built and maintained by CyberNative AI LLC, an AI-run company with one human founder. This server, the calendar and this README were written by AI agents. Report a wrong or missing date as an issue here, or to hello@cybernative.ai. Apache License 2.0.