Best for
- Projects using Ruby and Bundler, where AI agents need to perform code checks, dependency management, or script execution.
- AI integrations where token savings are important.
P
Pare Ruby
Community
Pare Ruby — Structured Ruby & Bundler operations as typed JSON.
- Category
- Dev Tools #380 of 438
- Stars
- ★ 138 Popular
- Transport
- stdio (local process)
- Runtime
- Node.js 20+ · Prebuilt binary
- Credentials
- No credential needed
- License
- MIT
- Last commit
- Tools
- 8
36FMRS · D
Pare Ruby provides structured Ruby/Bundler operations, suitable for AI agents requiring reliable, token-efficient output. It includes schema validation and tool filtering, but requires Node.js >=20, and permissions and risks need careful management.
Strongest · Setup experience 10/20 Weakest · Reliability 5/20
Why each score
- Reliability 5/20
- Only the manifest declares 8 tools and an npm package; the README's CI/coverage badges are repository-level and cannot be attributed to server-ruby. No source code, tests, or run logs for this server were provided, so the init handshake, tool list, actual behavior, and error handling cannot be verified. Missing evidence lowers the score; a conservative 5 is awarded.
- Security and permissions 6/20
- The server includes run, exec, and install tools that execute Ruby/Bundler commands locally and may trigger network-based installs. No server-ruby source or permission/confirmation documentation was supplied, so working-directory restrictions, confirmation of dangerous operations, and credential handling cannot be verified. No red-line issue such as malware or credential exfiltration is evident, but data boundaries and confirmation mechanisms are under-evidenced, yielding a score of 6.
- Maintenance 8/20
- The repository has an MIT license, is not archived, the manifest version is 0.22.0, and the README shows CI and OpenSSF badges. However, these are mostly repository-level signals; there is no server-ruby-specific commit history, release history, or issue-response evidence. Maintenance activity appears plausible but governance and timeliness evidence is insufficient, so the score is 8.
- Documentation 7/20
- The README provides general installation, tool filtering, and troubleshooting guidance, but no server-ruby-specific tool parameters, output schemas, limitations, or troubleshooting details. The linked docs/tool-schemas pages were not included and cannot be reviewed. Documentation is usable but has hidden assumptions and gaps, resulting in a score of 7.
- Setup experience 10/20
- The installation path is clear: npm package @paretools/ruby, stdio transport, npx invocation, and Node.js >= 20. The README also shows client configuration examples. However, no complete configuration command specific to this server and no platform compatibility verification were provided; without execution evidence in this static review, the score is set to 10, the lower bound of the allowable range without verifiable evidence.
Static review · not runListed 2026-08-07
Read the FMRS scoring method →Fit and risk
What it can accessReads local filesWrites / deletes local filesRuns commands or codeUses the network
Not for
- Simple Ruby script execution when structured output is not needed.
- Interactive Ruby sessions (e.g., IRB).
- MCP environments that do not support stdio transport.
Required permissions
- Execute Ruby and Bundler commands.
- Read gem installation directories, Gemfile, and related files.
- May create or modify gem-related files (e.g., during gem install).
- Network access (if installing gems from remote repositories).
Risks and side effects
- Executing arbitrary Ruby commands could lead to code execution risks; improper use by agents may cause security issues.
- Gem installation may modify the system environment; permissions must be used carefully.
- Tool output may contain sensitive information (e.g., gem versions) that should be protected.
- Supply chain risk: if the supply chain is compromised, installed gems could be unsafe.
Setup
Before you start
Runtime：Node.js 20+ · Prebuilt binary
Other optional settings (1)
PARE_TOOLS
Universal tool filter in server:tool,... format (e.g. ruby:run,gem-list) that limits registered tools across all Pare servers; nothing to obtain.
Install and configure via npm MCP. For Claude Code, add to MCP config:
{"mcpServers": {"pare-ruby": {"command": "npx", "args": ["-y", "@paretools/ruby"]}}}See project docs for other clients.
Check that it works
Check that the pare-ruby server appears in your client's tool list with tools like run, gem-list, and bundle-install, then call gem-list to confirm it returns structured JSON output.
Troubleshooting
- Verify Node.js version is >=20.
- Ensure npx path is correct (on Windows, may need cmd /c npx).
- Increase timeout using MCP_TIMEOUT environment variable to avoid connection timeouts.
- If tools are not registered, check tool filtering environment variables (PARE_TOOLS or PARE_RUBY_TOOLS).
Things to try
Once connected, you can ask your AI assistant things like:
- List the gems installed in this environment with versions
- Check which gems have updates available
- Install the nokogiri gem
- Run the rspec test suite through Bundler
Tools 8
run writes
Runs a Ruby script and returns structured results (e.g., output, exit code).
check read-only
Checks for Ruby syntax errors.
gem-list read-only
Lists installed gems, returning a formatted gem list.
gem-install writes
Installs one or more gems.
gem-outdated read-only
Checks for outdated gems.
bundle-install writes
Executes bundle install and returns installation results.
bundle-exec writes
Executes a command in the Bundler context.
bundle-check read-only
Checks if Gemfile dependencies are installed.
No matching tools
Use cases
AI agents that need to run Ruby/Bundler commands and get structured output for code analysis or automation.
Reduce CLI output token consumption to increase agent efficiency.
In CI/CD or dev environments, agents need reliable gem lists, versions, dependency status, etc.
Supported clients
Claude Desktop
Claude Code
Cursor
VS Code
Windsurf
Cline / Roo Code
Codex
Gemini CLI
Zed
Continue
Listed from the project's documentation, not tested by this site.
Overview
Pare Ruby is an MCP server that wraps common Ruby and Bundler commands (such as running scripts, syntax checking, gem management, and Bundler operations) and returns structured, schema-validated JSON instead of raw terminal text. It's part of the Pare toolset, designed to provide reliable, token-efficient CLI operations for AI agents.
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Source revision 57e1980e8375 Data synced 2026-10-13 Read the FMRS scoring method