Source MCP Server

Parse JavaScript error stack traces back to original source code using source maps

Local serverstdioTypeScript

What is the Source MCP server?

Parse JavaScript error stack traces back to original source code using source maps. That is what the source mcp server brings to an AI assistant: the same capability, reachable through the Model Context Protocol rather than a separate app or dashboard.

The short version

This project implements a WebAssembly-based Source Map parser that can map JavaScript error stack traces back to source code and extract relevant context information. Developers can easily map JavaScript error stack traces back to source code for quick problem identification and resolution. This documentation aims to help developers better understand and use this tool.

Getting it running

source-map-parser-mcp on npm is all you need. Most clients run it directly, so configuration is a few lines and a restart.

The tools it exposes

The server publishes 4 tools. What each one is for:

  • operating_guide — Get usage instructions for the MCP service. Provides information on how to use the MCP service through chat interaction
  • parse_stack — Parse stack information by providing stack traces and Source Map addresses
  • lookup_context — Look up original source code context for a specific line and column position in compiled/minified code
  • unpack_sources — Extract all source files and their content from a source map

What it needs from you

Configuration is passed through the environment: SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE, SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

Things to watch

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

How it compares

This sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Source's toolset — operating_guide, parse_stack, lookup_context and 1 more — is a fair guide to whether it matches your workflow. It is maintained by MasonChow; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Available tools

ToolWhat it does
operating_guideGet usage instructions for the MCP service. Provides information on how to use the MCP service through chat interaction.
parse_stackParse stack information by providing stack traces and Source Map addresses.
lookup_contextLook up original source code context for a specific line and column position in compiled/minified code.
unpack_sourcesExtract all source files and their content from a source map.

How to install the Source MCP server

{
  "mcpServers": {
    "source-map-parser": {
      "command": "npx",
      "args": ["-y", "source-map-parser-mcp"],
      "env": {
        "SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE": "your-value",
        "SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

VariableDescriptionRequired
SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZEConfiguration value read at startup.Optional
SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINEConfiguration value read at startup.Optional

Example prompts to try

  • Use Source to operating guide.
  • Use Source to parse stack.
  • Use Source to lookup context.

Frequently asked questions

It connects Source to MCP-compatible AI assistants such as Claude and Cursor, exposing 4 tools (operating_guide, parse_stack, lookup_context, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Source directly.