Errs

Compact error/lint parser MCP tool. Normalizes verbose compiler and linter output into structured [{file, line, col, code, severity, message}] JSON. Strips ANSI codes, ASCII underlines, column markers, and repeated file paths.

Supported Formats

Format	Auto-detected	Examples
Go	yes	go build, go vet, golangci-lint
GCC/Clang	yes	gcc, clang, Swift compiler
Rust	yes	rustc, cargo build, clippy
TypeScript	yes	tsc
ESLint	yes	ESLint stylish formatter
dotnet/C#	yes	dotnet build, Roslyn, FxCop, StyleCop
Python	yes	flake8, pycodestyle, mypy
Kotlin	yes	kotlinc, Gradle

Installation

go build -o errs
sudo cp errs /usr/local/bin/
codesign -s - /usr/local/bin/errs  # macOS

Or with just:

just install

Usage

CLI Mode

Pipe compiler/linter output through errs:

go build ./... 2>&1 | errs --cli
dotnet build 2>&1 | errs --cli
cargo build 2>&1 | errs --cli

With a format hint (bypasses auto-detection):

eslint src/ 2>&1 | errs --cli --format eslint

Read from file:

errs --cli --file build-errors.txt

MCP Mode

Default mode (no flags) runs as an MCP stdio server with a single errs tool:

• input (string, required): Raw error/lint output
• format (string, optional): Format hint — go, eslint, tsc, rust, gcc, dotnet

Output

{
  "errors": [
    {"file": "main.go", "line": 10, "col": 5, "message": "undefined: foo"},
    {"file": "main.go", "line": 15, "col": 3, "code": "SA1019", "message": "strings.Title is deprecated"}
  ],
  "format": "colon",
  "count": 2,
  "files": 1,
  "summary": "2 errors in 1 file"
}

MCP Configuration

Add to .mcp.json:

{
  "mcpServers": {
    "errs": {
      "command": "errs"
    }
  }
}

License

MIT