Compare Xml

What is Compare Xml?

Compare Xml is a toolkit for structured XML comparison — it finds what changed between two XML documents, with control over how keys, values, and arrays are matched. It provides a core library, a command-line tool, an MCP server, and an agent skill for AI coding assistants.

How to use Compare Xml?

Install the CLI globally with npm install -g @compare-xml/cli, then run compare-xml base.xml contrast.xml. For programmatic use, install the core library with npm install @compare-xml/core and call its compareXML function. To use the MCP server, add a config entry with command npx @compare-xml/cli@latest --mcp. An agent skill can be installed via npx skills add unitstack/compare-xml.

Key features of Compare Xml

• Deep comparison of XML elements, attributes, arrays, and text values.
• Three array comparison strategies: byIndex, lcs, and unordered.
• Case-insensitive key and/or value matching.
• Path tracking with both segment-array and dot-notation forms.
• CLI with table or JSON output, reading from inline strings or files.
• Built-in MCP server for MCP-aware AI assistants.
• Agent Skill that works in Claude Code, OpenAI Codex CLI, and others.
• Full TypeScript types.

Use cases of Compare Xml

• Finding structural differences between two XML configuration files.
• Programmatically detecting additions, deletions, and value changes in XML data.
• Integrating XML diff capabilities into an AI assistant via the MCP protocol.
• Comparing XML payloads in automated testing or CI/CD pipelines.
• Teaching AI coding assistants to perform XML comparison on demand using the agent skill.

FAQ from Compare Xml

What array comparison strategies are available?

Three strategies: byIndex (default), lcs (minimal diff via Longest Common Subsequence), and unordered (multiset match).

How can I get machine-readable output from the CLI?

Use the --json-export flag to produce JSON output instead of the default table format.

What are the runtime requirements for using Compare Xml?

Development requires Node.js 20 or higher and pnpm. The CLI and library can be used with any Node.js environment that meets the package dependencies.

How do I use the MCP server?

Add a configuration entry with "command": "npx" and "args": ["@compare-xml/cli@latest", "--mcp"] under mcpServers in your MCP client settings.

How do I install the agent skill for AI coding assistants?

Run npx skills add unitstack/compare-xml — it auto-detects installed agents and drops the skill into each one. The skill file follows the open Agent Skills format.