Server Doctor

Server Doctor (day-2 operations)

Keep a running server healthy. Three jobs, all local and read-only — paste a log or point at a server folder; never run live commands or write to a panel (that is a future operator mode). Never invent config keys or plugin behaviour; confirm specifics with learn-plugin-docs.

1. Diagnose a crash or error (/mcwrench:diagnose)

The headline. Read a crash-reports/crash-*.txt, logs/latest.log, or pasted text and return a ranked root cause.

node "${CLAUDE_PLUGIN_ROOT}/skills/server-doctor/scripts/parse-log.mjs" 
#   or pipe:  cat latest.log | node .../parse-log.mjs
#   add --json for machine output

It names the likely culprit namespace (the first non-engine stack frame), and matches signatures in references/log-signatures.md: UnsupportedClassVersionError (Java too old — class file version 69 = Java 25), OutOfMemoryError, Watchdog / single-tick overload, ticking entity/world crashes, port already in use, EULA not accepted, plugin load failures (Unsupported API version / missing dependency), NoClassDefFoundError/NoSuchMethodError. Each finding has a fix recipe; route a named plugin to learn-plugin-docs and lag findings to performance-tuning. Cross-reference the server-profile (Java/software/plugins) to disambiguate (e.g. UnsupportedClassVersionError on a 26.1 jar = Java # software, version, plugins, footguns node "${CLAUDEPLUGINROOT}/skills/audit-config/scripts/check-conflicts.mjs" # plugin conflicts + missing deps node "${CLAUDEPLUGINROOT}/skills/server-doctor/scripts/check-plugin-versions.mjs" # outdated / no-build-for-this-MC node "${CLAUDEPLUGINROOT}/skills/server-doctor/scripts/parse-log.mjs" # today's crash/log, if any

Grade four areas — **security, performance, durability, currency** — list the top fixes prioritised
critical to low, and hand deep tuning to `performance-tuning` and config lint to `audit-config`. Use
the server-profile so you do not re-ask known facts.

## 3. Upgrade / migration planner  (`/mcwrench:upgrade`)
Given the server-profile and a target version, produce a go/no-go runbook. Use
`references/upgrade-checklist.md`. The big 2026 facts:
- **Paper 26.1+ requires Java 25** — flag `UnsupportedClassVersionError` risk if Java is older.
- **26.1 dropped the obfuscated jar**: Spigot-mapped plugins must be re-released for 26.1, so many
  silently break. For each installed plugin, label **has a 26.1 build / none / unknown** using
  `check-plugin-versions.mjs` + `learn-plugin-docs`.
- Do **not** combine a version bump with a software/server-type switch in one step.
- World-upgrade caveats: back up and trim first; test on a copy before upgrading the live world.
Emit an ordered runbook: **back up → bump Java → update plugins (verify builds) → test on a copy →
upgrade the world**. Read-only: it never downloads or writes.

## Guardrails
- Local + read-only. No RCON, no panel writes, no console commands (that is v2).
- Never invent config keys or claim a plugin behaviour you have not read; fetch with `learn-plugin-docs`.
- Always confirm a destructive step (world upgrade, deleting regions) and tell the user to back up first.

## References + scripts
- `references/log-signatures.md` — the crash/log signature catalogue + fix recipes.
- `references/upgrade-checklist.md` — the 26.1 / Java 25 / cross-version migration runbook.
- `scripts/parse-log.mjs` — crash/log analyzer (read-only, no deps).
- `scripts/check-plugin-versions.mjs` — staleness + MC/loader-compat report (Modrinth; `--offline` ok).

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Teddy563](https://github.com/Teddy563)
- **Source:** [Teddy563/mcwrench](https://github.com/Teddy563/mcwrench)
- **License:** MIT
- **Homepage:** https://mcwrench.teddy.bar

Install and usage instructions live in the source repository linked above.