MCP Server Fails

[egelja]

What happen
MCP server is failing

Expected
MCP server should work

Before/after example

Platform

• Claude Code
• Codex
• Other: ___

Version / install method

Version ef6050c5e184, installed through default bash installer

[dgokcin]

+1

[luysfernnando]

+1

[rntjr]

+1 mine failed in wsl

➜  midwest git:(main) ✗ curl -fsSL https://raw.githubusercontent.com/JuliusBrussee/caveman/main/install.sh | zsh
🪨 caveman installer
  JuliusBrussee/caveman

→ Claude Code detected
  $ claude plugin marketplace add JuliusBrussee/caveman
✔ Marketplace 'caveman' already on disk — declared in user settings
  $ claude plugin install caveman@caveman
Installing plugin "caveman@caveman"...
✘ Failed to install plugin "caveman@caveman": Source path does not exist: /home/rntjr/midwest/C:\Users\rntjr\.claude\plugins\marketplaces\caveman
  → installing hooks (--with-hooks)
  installed: /home/rntjr/.claude/hooks/package.json
  installed: /home/rntjr/.claude/hooks/caveman-config.js
  installed: /home/rntjr/.claude/hooks/caveman-activate.js
  installed: /home/rntjr/.claude/hooks/caveman-mode-tracker.js
  installed: /home/rntjr/.claude/hooks/caveman-stats.js
  installed: /home/rntjr/.claude/hooks/caveman-statusline.sh
  installed: /home/rntjr/.claude/hooks/caveman-statusline.ps1
  statusline badge configured.
  hooks wired in /home/rntjr/.claude/settings.json
  → wiring caveman-shrink MCP proxy (--with-mcp-shrink)
  $ claude mcp add caveman-shrink -- npx -y caveman-shrink
Added stdio MCP server caveman-shrink with command: npx -y caveman-shrink to local config
File modified: /home/rntjr/.claude.json [project: /home/rntjr/midwest]
    registered. Wrap an upstream by editing the mcpServers entry — see:
    https://github.com/JuliusBrussee/caveman/tree/main/src/mcp-servers/caveman-shrink

→ Cursor detected
  $ npx -y skills add JuliusBrussee/caveman -a cursor --yes --all

███████╗██╗  ██╗██╗██╗     ██╗     ███████╗
██╔════╝██║ ██╔╝██║██║     ██║     ██╔════╝
███████╗█████╔╝ ██║██║     ██║     ███████╗
╚════██║██╔═██╗ ██║██║     ██║     ╚════██║
███████║██║  ██╗██║███████╗███████╗███████║
╚══════╝╚═╝  ╚═╝╚═╝╚══════╝╚══════╝╚══════╝

┌   skills
│
│  Tip: use the --yes (-y) and --global (-g) flags to install without prompts.
│
◇  Source: https://github.com/JuliusBrussee/caveman.git
│
◇  Repository cloned
│
◇  Found 7 skills
│
●  Installing all 7 skills
│
●  Installing to all 55 agents

│
◇  Installation Summary ────────────────────────────────────────────────────╮
│                                                                           │
│  ~/midwest/.agents/skills/cavecrew                                        │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
│  ~/midwest/.agents/skills/caveman                                         │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
│  ~/midwest/.agents/skills/caveman-commit                                  │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
│  ~/midwest/.agents/skills/caveman-compress                                │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
│  ~/midwest/.agents/skills/caveman-help                                    │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
│  ~/midwest/.agents/skills/caveman-review                                  │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
│  ~/midwest/.agents/skills/caveman-stats                                   │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more             │
│    symlink → AiderDesk, Augment, IBM Bob, Claude Code, OpenClaw +35 more  │
│    overwrites: Amp, Antigravity, Cline, Codex, Cursor +10 more            │
│                                                                           │
├───────────────────────────────────────────────────────────────────────────╯
│
◇  Security Risk Assessments ───────────────────────────────────────╮
│                                                                   │
│                    Gen               Socket            Snyk       │
│  cavecrew          Safe              0 alerts          Low Risk   │
│  caveman           Safe              0 alerts          Low Risk   │
│  caveman-commit    Safe              0 alerts          Low Risk   │
│  caveman-compress  Safe              0 alerts          High Risk  │
│  caveman-help      Safe              0 alerts          Low Risk   │
│  caveman-review    Safe              0 alerts          Med Risk   │
│  caveman-stats     Safe              0 alerts          Low Risk   │
│                                                                   │
│  Details: https://skills.sh/JuliusBrussee/caveman                 │
│                                                                   │
├───────────────────────────────────────────────────────────────────╯
│
◇  Installation complete

│
◇  Installed 7 skills ───────────────────────────────────────────╮
│                                                                │
│  ✓ ~/midwest/.agents/skills/cavecrew                           │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│  ✓ ~/midwest/.agents/skills/caveman                            │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│  ✓ ~/midwest/.agents/skills/caveman-commit                     │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│  ✓ ~/midwest/.agents/skills/caveman-compress                   │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│  ✓ ~/midwest/.agents/skills/caveman-help                       │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│  ✓ ~/midwest/.agents/skills/caveman-review                     │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│  ✓ ~/midwest/.agents/skills/caveman-stats                      │
│    universal: Amp, Antigravity, Cline, Codex, Cursor +10 more  │
│                                                                │
├────────────────────────────────────────────────────────────────╯

│
└  Done!  Review skills before use; they run with full agent permissions.


  tip: re-run inside a repo with --all (or --with-init) to also write per-repo
       Cursor/Windsurf/Cline/Copilot/AGENTS.md rule files.

🪨 done
  installed:
    • claude-hooks
    • caveman-shrink
    • cursor
  failed:
    • claude — claude plugin install failed

  start any session and say 'caveman mode', or run /caveman in Claude Code
  uninstall: npx -y github:JuliusBrussee/caveman -- --uninstall

[rgaufman]

I thought maybe this will help, but it does not: npm install -g caveman-shrink

[alaa-alghazouli]

I've submitted a PR that fixes the caveman-shrink MCP registration. It was incorrectly being configured as a standalone server when it actually requires upstream wrapping. The fix removes auto-registration and adds instructions for manual wrapping.

PR: #452