Upgradepath MCP Server

upgradepath

Upgrading a dependency is rarely one jump. The releases between where you are and where you want to be each carry their own breaking changes, and the order you pass through them matters. upgradepath plans that walk for a single dependency. You supply the facts — the name, the version you have, the version you want, and the known releases with the breaking changes and deprecation flags you have recorded for each — and it returns the ordered steps in between, what each step breaks, and a verdict for the whole path.

Nothing is fetched. Versions are never looked up and changes are never guessed; every fact in the plan came from the caller. Only releases numerically greater than the current version and at most the target become steps, sorted ascending. Versions are written x.y.z and compare numerically, so 01.2.3 and 1.2.3 are the same version — including when that makes two supplied releases duplicates, which is an error. The target must be greater than the current version, or the plan is rejected before any step is chosen.

Alongside the steps, the result counts how many major boundaries the chain crosses, walking from the current version through each step in order, and reports whether the last step actually reaches the target: a release list that stops short still produces a plan, but reaches_target says plainly that it does not arrive. The verdict is decided in a fixed precedence. No steps at all is no_path. A path carrying no breaking changes is clean. Three or fewer breaking changes in total is manageable, and anything beyond that is major_effort — so a step-less plan is no_path even though its breaking total is zero.

Each step echoes its version and its breaking changes exactly as supplied, counts those changes, and reports whether the release is deprecated (false when the caller did not say). Malformed input — a missing, empty, or non-string name, a version outside the x.y.z grammar, a missing, non-array, or empty releases list, a malformed release entry, a duplicate release version, or a target that is not greater than the current version — is a validation error naming the offending path, with no partial result. Unknown extra fields are ignored, including inside release entries.

CLI

npx @reneturcios/upgradepath plan --input args.json
npx @reneturcios/upgradepath --version

args.json contains the full arguments object:

{
  "name": "widgetlib",
  "current": "1.2.3",
  "target": "3.0.0",
  "releases": [
    { "version": "1.3.0" },
    {
      "version": "2.0.0",
      "breaking_changes": ["removed the legacy parser entry point"]
    },
    {
      "version": "2.4.1",
      "breaking_changes": ["renamed the configuration keys", "dropped Node 14 support"],
      "deprecated": true
    },
    { "version": "3.0.0" }
  ]
}

The result is printed as JSON:

{
  "name": "widgetlib",
  "current": "1.2.3",
  "target": "3.0.0",
  "steps": [
    {
      "version": "1.3.0",
      "breaking_changes": [],
      "breaking_count": 0,
      "deprecated": false
    },
    {
      "version": "2.0.0",
      "breaking_changes": ["removed the legacy parser entry point"],
      "breaking_count": 1,
      "deprecated": false
    },
    {
      "version": "2.4.1",
      "breaking_changes": ["renamed the configuration keys", "dropped Node 14 support"],
      "breaking_count": 2,
      "deprecated": true
    },
    {
      "version": "3.0.0",
      "breaking_changes": [],
      "breaking_count": 0,
      "deprecated": false
    }
  ],
  "step_count": 4,
  "total_breaking": 3,
  "majors_crossed": 2,
  "reaches_target": true,
  "verdict": "manageable"
}

Exit codes: 0 on success, 1 on a runtime error (including an unreadable or invalid input file, or invalid input), 2 on a usage error.

MCP server

npx -y @reneturcios/upgradepath mcp

MCP client config:

{
  "mcpServers": {
    "upgradepath": {
      "command": "npx",
      "args": ["-y", "@reneturcios/upgradepath", "mcp"]
    }
  }
}

Tools

• plan_upgrade_path — Plan a safe dependency upgrade from caller-supplied release facts.

  • name (string, required, non-empty) — dependency name
  • current (string, required) — currently installed version, in x.y.z form
  • target (string, required) — target version, in x.y.z form; must be greater than current
  • releases (array, required, at least 1 item) — known releases of the dependency; each item has:
    • version (string, required) — release version, in x.y.z form
    • breaking_changes (array of strings, optional) — breaking changes introduced by this release; absent means none
    • deprecated (boolean, optional) — whether this release is deprecated; absent means false

  Returns {name, current, target, steps, step_count, total_breaking, majors_crossed, reaches_target, verdict}, where each step is {version, breaking_changes, breaking_count, deprecated}.

Docker

docker run -i ghcr.io/cloudcorprecords/upgradepath
docker run --rm -v "$PWD:/w" ghcr.io/cloudcorprecords/upgradepath plan --input /w/args.json

Development

npm install
npm run build   # tsc -> dist/
npm test        # tsx --test test/*.test.ts (pure local, no network)
npm run dev     # run the CLI from source

License

MIT — Copyright (c) 2026 Rene Turcios