rebar-semver
MCP server: semantic-version math, compare, satisfies, parse, sort, increment, diff, range-match, validate. Pure compute, deterministic where LLMs guess.
semver
semantic-versioning
version-compare
+7
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rebar-semver
LLMs guess version math from memory and get it wrong in predictable ways:
- Numeric precedence read as string order — 1.0.10 looks "less than" 1.0.9 character-by-character. It isn't.
- Prerelease ordering — 1.0.0-beta.2 vs 1.0.0-beta.10, and the rule that any prerelease is lower than its release (1.0.0-rc.1 < 1.0.0).
- Range semantics — what ^1.2.0 actually admits, and that prereleases are excluded from ranges unless explicitly opted in.
It crashes on bad input
The underlying library throws a TypeError on a malformed version — the exact failure behind anthropics/claude-code#16708, where an LLM-supplied "2.1.0 (2026-01-07)" crashed a version sort. Every tool here catches that and returns an actionable error instead of a 500. Graceful, deterministic handling is the whole point.