io.github.Dave-London/pare-python MCP Server
io.github.Dave-London/pare-python
Structured Python tool output (ruff, mypy, pip, uv, black, pytest) as typed JSON for AI agents.
What is the io.github.Dave-London/pare-python MCP server?
The Pare Python MCP server wraps common Python development tools (ruff, mypy, pip, uv, black, pytest) and returns clean, schema-validated JSON instead of raw terminal text. It eliminates fragile CLI parsing by providing typed, consistent output across platforms and tool versions.
Pare Python converts Python tooling output into structured JSON that AI agents can process directly without string parsing. It wraps linters, type checkers, package managers, and test runners—reducing token usage by 65–95% compared to raw CLI output while ensuring reliable, platform-independent data.
How to install io.github.Dave-London/pare-python
Copy-paste configuration for popular MCP clients.
Tools & capabilities
Tools this server exposes to the agent.
ruff— Python linter and formatter output as structured JSONmypy— Static type checker output as structured JSONpip— Package manager operations and dependency output as structured JSONuv— Fast Python package installer output as structured JSONblack— Code formatter output as structured JSONpytest— Test runner results as structured JSON
Use cases
- Run linters and type checkers, get structured results for CI/CD pipelines without parsing terminal text
- Install and manage Python dependencies via pip or uv, receive dependency trees and conflict reports as JSON
- Execute pytest test suites and extract pass/fail status, coverage, and failure details as typed data
- Format code with black and capture formatting changes in structured form
- Combine multiple Python tools in agent workflows with reliable, token-efficient output
io.github.Dave-London/pare-python MCP server FAQ
Pare Python is an MCP server that wraps Python development tools (ruff, mypy, pip, uv, black, pytest) and returns their output as schema-validated JSON instead of raw terminal text. This eliminates parsing fragility and reduces token usage by 65–95%.
Yes, Pare is open-source under the MIT license.
Use the quick setup: `npx @paretools/init --client claude-code --preset python` (or `cursor` for Cursor). Then restart your client. See setup guides at https://github.com/Dave-London/Pare/tree/main/docs/setup for detailed instructions per client.
No. Pare wraps local CLI tools you already have installed (ruff, mypy, pip, uv, black, pytest). It requires Node.js >= 20 and the Python tools in your PATH.
Yes. Use environment variables like `PARE_PYTHON_TOOLS=pytest,mypy` to restrict tools, or `PARE_TOOLS=python:pytest,python:mypy` for universal filtering. Set via the `env` key in your MCP config.
Pare works on macOS, Linux, and Windows. Output is consistent across platforms and tool versions, eliminating locale-specific formatting differences.
README (reference)
Source of truth, from the repository.
Reliable, structured CLI output for AI agents — no more parsing fragile terminal text.
Pare provides MCP servers that wrap common developer tools (git, npm, docker, test runners, etc.) and return clean, schema-validated JSON instead of raw terminal text. Agents get typed data they can act on directly, without brittle string parsing.
The Problem
Parsing CLI output is fragile. Raw terminal text includes ANSI escape codes, decorative headers, progress bars, locale-specific formatting, and platform differences that break agent workflows in subtle ways. An agent that works fine with git status on macOS may fail on Windows because the output format changed. A test runner's summary line might shift between versions, silently breaking a regex.
Pare eliminates this entire class of errors by returning schema-validated JSON with consistent field names, regardless of platform, tool version, or locale. As a bonus, structured output is significantly smaller — agents use fewer tokens per tool call:
| Tool Command | Raw Tokens | Pare Tokens | Reduction |
|---|---|---|---|
docker build (multi-stage, 11 steps) | 373 | 20 | 95% |
git log --stat (5 commits, verbose) | 4,992 | 382 | 92% |
npm install (487 packages, warnings) | 241 | 41 | 83% |
vitest run (28 tests, all pass) | 196 | 39 | 80% |
cargo build (2 errors, help text) | 436 | 138 | 68% |
pip install (9 packages, progress bars) | 288 | 101 | 65% |
cargo test (12 tests, 2 failures) | 351 | 190 | 46% |
npm audit (4 vulnerabilities) | 287 | 185 | 36% |
Token estimates use ~4 chars/token. The biggest savings appear on verbose commands (builds, installs, tests). For simpler tools like
eslintortsc, the main advantage is reliable structured data — agents can use typed JSON directly rather than parsing strings.
How It Works
Each Pare tool returns two outputs:
content— human-readable text, for MCP clients that display itstructuredContent— typed, schema-validated JSON, ready for agents to process
This uses MCP's structuredContent and outputSchema features to provide type-safe, validated data that agents can rely on without custom parsing.
Example: git status
Raw git output (~118 tokens):
On branch main
Your branch is ahead of 'origin/main' by 2 commits.
(use "git push" to publish your local commits)
Changes to be committed:
(use "git restore --staged <file>..." to unstage)
modified: src/index.ts
new file: src/utils.ts
Changes not staged for commit:
(use "git add <file>..." to update what will be committed)
(use "git restore <file>..." to discard changes in working directory)
modified: README.md
Untracked files:
(use "git add <file>..." to include in what will be committed)
temp.log
Pare structured output (~59 tokens):
{
"branch": "main",
"upstream": "origin/main",
"ahead": 2,
"staged": [
{ "file": "src/index.ts", "status": "modified" },
{ "file": "src/utils.ts", "status": "added" }
],
"modified": ["README.md"],
"deleted": [],
"untracked": ["temp.log"],
"conflicts": [],
"clean": false
}
50% fewer tokens. Zero information lost. Fully typed. Savings scale with output verbosity — test runners and build logs see 80–92% reduction.
Available Servers (28 packages, 240 tools)
Install only the servers relevant to your stack — most projects need just 2–4. The full catalog covers a wide range of ecosystems so Pare works wherever you do.
| Category | Servers | Tools | Wraps |
|---|---|---|---|
| Version Control | git, github | 55 | git, gh |
| Languages & Packages | npm, python, cargo, go, deno, bun, nix, dotnet, ruby, swift, jvm | 101 | npm, pip, cargo, go, deno, bun, nix, dotnet, gem, swift, gradle, maven |
| Build, Lint & Test | build, lint, test, cmake, bazel | 23 | tsc, esbuild, vite, webpack, eslint, prettier, biome, vitest, pytest, jest |
| Infrastructure | docker, k8s, infra, security, remote | 40 | docker, kubectl, helm, terraform, ansible, trivy, ssh |
| Utilities | search, http, make, process, db | 21 | ripgrep, fd, curl, make, just, psql, mysql, redis, mongosh |
Tool Schemas — detailed response examples and field descriptions for every tool. See also Tool Response Examples for quick JSON samples.
Quick Setup
# 1. Configure MCP servers (non-interactive)
npx @paretools/init --client claude-code --preset web
# 2. Add agent rules to your project
# (append to existing CLAUDE.md, or copy if new)
cat node_modules/@paretools/init/rules/CLAUDE.md >> CLAUDE.md
# 3. Restart your client session
# 4. Validate
npx @paretools/init doctor
Available presets: web, python, rust, go, jvm, dotnet, ruby, swift, mobile, devops, full
Setup Guides by Client
| Claude Code | Claude Desktop | Cursor |
| VS Code / Copilot | Windsurf | Cline / Roo Code |
| OpenAI Codex | Gemini CLI | Zed |
| Continue.dev |
Full Quickstart Guide — presets, ecosystem mapping, validation
Manual Configuration — config paths and formats for all clients
Agent Integration Guide — rule files, hooks, CLI-to-MCP mapping
Configuration
Tool Selection
By default, every Pare server registers all of its tools. If a server exposes tools you don't need — or you want to limit which tools are available to an agent — you can filter them with environment variables.
Per-server filter — restrict a single server's tools:
# Only register status and log in the git server
PARE_GIT_TOOLS=status,log npx @paretools/git
Universal filter — restrict tools across all servers:
# Only register these specific tools across any server
PARE_TOOLS=git:status,git:log,npm:install npx @paretools/git
Disable all tools — set the env var to an empty string:
PARE_GIT_TOOLS= npx @paretools/git # no tools registered
| Env Var | Scope | Format | Example |
|---|---|---|---|
PARE_TOOLS | All servers | server:tool,... | git:status,npm:install |
PARE_{SERVER}_TOOLS | One server | tool,... | status,log,diff |
Rules:
- No env var = all tools enabled (default)
PARE_TOOLS(universal) takes precedence over per-server vars- Server names use uppercase with hyphens replaced by underscores (e.g.,
PARE_MY_SERVER_TOOLS) - Whitespace around commas is ignored
Common patterns:
# Read-only git (no push, commit, add, checkout)
PARE_GIT_TOOLS=status,log,diff,branch,show
# Minimal npm
PARE_NPM_TOOLS=install,test,run
# Only specific tools across all servers
PARE_TOOLS=git:status,git:diff,npm:install,test:run
In JSON MCP config, set via the env key:
{
"mcpServers": {
"pare-git": {
"command": "npx",
"args": ["-y", "@paretools/git"],
"env": {
"PARE_GIT_TOOLS": "status,log,diff,show"
}
}
}
}
Troubleshooting
| Issue | Solution |
|---|---|
npx not found / ENOENT on Windows | Use cmd /c npx wrapper (see your client's setup guide) |
| Slow first start | Run npx -y @paretools/git once to cache, or install globally: npm i -g @paretools/git |
| Node.js version error | Pare requires Node.js >= 20 |
| NVM/fnm PATH issues | Use absolute path to npx: e.g., ~/.nvm/versions/node/v22/bin/npx |
| MCP connection timeout | Set MCP_TIMEOUT=30000 for Claude Code, or increase initTimeout in client config |
| Too many tools filling context | Use tool selection env vars to limit tools, or only install the servers you need |
Contributing
Each server is a self-contained package. See CONTRIBUTING.md for the full guide.
License
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