io.github.Dave-London/cargo

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 eslint or tsc, 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 it
• structuredContent — 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
 

... [View full README on GitHub](https://github.com/Dave-London/Pare#readme)