Claustodian

Ship features that match the user's Claude Code version. Pick a version, search the surface.

Three ways version drift bites — click to see the answer

Use it from your own code — curl, Python, TypeScript

Static JSON at stable URLs — no API, no key, no install. A version snapshot lists only the symbols available at that version, so presence is the answer. 

# Does --safe-mode exist in 2.1.169?  (exit 0 = yes)
curl -fsSL https://claustodian.dev/data/versions/2.1.169.json \
  | jq -e '.symbols[] | select(.symbol == "--safe-mode")' >/dev/null \
  && echo available || echo "not available"
# stdlib only
import json, urllib.request

url = "https://claustodian.dev/data/versions/2.1.169.json"
with urllib.request.urlopen(url) as r:
    snap = json.load(r)

print(any(s["symbol"] == "--safe-mode" for s in snap["symbols"]))
// zero dependencies, Node 18+
const url = 'https://claustodian.dev/data/versions/2.1.169.json';
const snap = await fetch(url).then((r) => r.json());

console.log(snap.symbols.some((s) => s.symbol === '--safe-mode'));

Fuller clients, all runnable and dependency-light: quickstart.sh, claustodian.py, claustodian.ts. Building on top of this with an agent? Point it at llms.txt.

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