How do I install Source Map Parser?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Source Map Parser need an API key?

The publisher lists these environment variables: SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE, SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE.

What transport does Source Map Parser use?

Source Map Parser runs locally over stdio.

When was Source Map Parser last checked?

Last checked 2026-11-09. Parse JavaScript error stack traces back to original source code using source maps

Source Map Parser MCP server

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y [email protected]

Credentials from the publisher

SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE — Context lines around error locations in source code
SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE — Maximum memory cache size in MB for source maps

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE=<value> SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE=<value> claude mcp add io.github.masonchow-source-map-parser-mcp -- npx -y source-map-parser-mcp@1.3.2

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.masonchow-source-map-parser-mcp": {4      "command": "npx",5      "args": [6        "-y",7        "[email protected]"8      ],9      "env": {10        "SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE": "<value>",11        "SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE": "<value>"12      }13    }14  }15}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 1.3.2

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

Source Map Parser

🌐 语言: English | 简体中文

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.

MCP Integration

Note: Requires Node.js 20+ support

Option 1: Run directly with NPX

npx -y source-map-parser-mcp@latest

Option 2: Download the build artifacts

Download the corresponding version of the build artifacts from the GitHub Release page, then run:

node dist/main.es.js

Use as an npm package (bring your own MCP server)

You can embed the tools into your own MCP server process and customize behavior.

Install:

npm install source-map-parser-mcp

Minimal server (TypeScript):

import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import {
  registerTools,
  Parser,
  type ToolsRegistryOptions,
} from 'source-map-parser-mcp';

const server = new McpServer(
  { name: 'your-org.source-map-parser', version: '0.0.1' },
  { capabilities: { tools: {} } }
);

// Optional: control context lines via env
const options: ToolsRegistryOptions = {
  contextOffsetLine:
    Number(process.env.SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE) || 1,
};

registerTools(server, options);

// Start as stdio server
const transport = new StdioServerTransport();
await server.connect(transport);

// If you need programmatic parsing without MCP:
const parser = new Parser({ contextOffsetLine: 1 });
// await parser.parseStack({ line: 10, column: 5, sourceMapUrl: 'https://...' });
// await parser.batchParseStack([{ line, column, sourceMapUrl }]);

Build and Type Declarations

This project ships both ESM and CJS builds and a single bundled TypeScript declaration file.

Build outputs:
- ESM: dist/index.es.js
- CJS: dist/index.cjs.js
- CLI entry: dist/main.es.js
- Types: dist/index.d.ts (single bundled d.ts)

Quick build locally:

npm install
npm run build

Using types in your project:

import {
  Parser,
  registerTools,
  type ToolsRegistryOptions,
} from 'source-map-parser-mcp';

Runtime Parameter Configuration

System runtime parameters can be flexibly configured through environment variables to meet the needs of different scenarios

SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE: Sets the maximum memory space occupied by resource cache, default is 200MB. Adjusting this value appropriately can balance performance and memory usage.
SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE: Defines the number of context code lines to display around the error location, default is 1 line. Increasing this value provides more context information, facilitating problem diagnosis.

Example:

# Set 500MB cache and display 3 lines of context
export SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE=500
export SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE=3
npx -y source-map-parser-mcp@latest

Feature Overview

Stack Parsing: Parse the corresponding source code location based on provided line number, column number, and Source Map file.
Batch Processing: Support parsing multiple stack traces simultaneously and return batch results.
Context Extraction: Extract context code for a specified number of lines to help developers better understand the environment where errors occur.
Context Lookup: Look up original source code context for specific compiled code positions.
Source Unpacking: Extract all source files and their content from source maps.

MCP Service Tool Description

`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.

Request Example

stacks: Stack information including line number, column number, and Source Map address.
- line: Line number, required.
- column: Column number, required.
- sourceMapUrl: Source Map address, required.

{
  "stacks": [
    {
      "line": 10,
      "column": 5,
      "sourceMapUrl": "https://example.com/source.map"
    }
  ]
}

Response Example

{
  "content": [
    {
      "type": "text",
      "text": "[{\"success\":true,\"token\":{\"line\":10,\"column\":5,\"sourceCode\":[{\"line\":8,\"isStackLine\":false,\"raw\":\"function foo() {\"},{\"line\":9,\"isStackLine\":false,\"raw\":\"  console.log('bar');\"},{\"line\":10,\"isStackLine\":true,\"raw\":\"  throw new Error('test');\"},{\"line\":11,\"isStackLine\":false,\"raw\":\"}\"}],\"src\":\"index.js\"}}]"
    }
  ]
}

`lookup_context`

Look up original source code context for a specific line and column position in compiled/minified code.

Request Example

line: The line number in the compiled code (1-based), required.
column: The column number in the compiled code, required.
sourceMapUrl: The URL of the source map file, required.
contextLines: Number of context lines to include (default: 5), optional.

{
  "line": 42,
  "column": 15,
  "sourceMapUrl": "https://example.com/app.js.map",
  "contextLines": 5
}

Response Example

{
  "content": [
    {
      "type": "text",
      "text": "{\"filePath\":\"src/utils.js\",\"targetLine\":25,\"contextLines\":[{\"lineNumber\":23,\"content\":\"function calculateSum(a, b) {\"},{\"lineNumber\":24,\"content\":\"  if (a < 0 || b < 0) {\"},{\"lineNumber\":25,\"content\":\"    throw new Error('Negative numbers not allowed');\"},{\"lineNumber\":26,\"content\":\"  }\"},{\"lineNumber\":27,\"content\":\"  return a + b;\"}]}"
    }
  ]
}

`unpack_sources`

Extract all source files and their content from a source map.

Request Example

sourceMapUrl: The URL of the source map file to unpack, required.

{
  "sourceMapUrl": "https://example.com/bundle.js.map"
}

Response Example

{
  "content": [
    {
      "type": "text",
      "text": "{\"sources\":{\"src/index.js\":\"import { utils } from './utils.js';\\nconsole.log('Hello World!');\",\"src/utils.js\":\"export const utils = { add: (a, b) => a + b };\"},\"sourceRoot\":\"/\",\"file\":\"bundle.js\",\"totalSources\":2}"
    }
  ]
}

Parsing Result Description

success: Indicates whether the parsing was successful.
token: The Token object returned when parsing is successful, containing source code line number, column number, context code, and other information.
error: Error information returned when parsing fails.

Example Run

System Prompt

According to actual needs, you can use system prompts to guide the model on how to parse stack information. For security or performance reasons, some teams may not want to expose Source Maps directly to the browser for parsing, but instead process the upload path of the Source Map. For example, converting the path bar-special.js to special/bar.js.map. In this case, you can instruct the model to perform path conversion through prompt rules.

Here is an example:

# Error Stack Trace Parsing Rules

When performing source map parsing, please follow these rules:

1. If the URL contains `special`, the file should be parsed into the `special/` directory, while removing `-special` from the filename.
2. All source map files are stored in the following CDN directory:  
   `https://cdn.jsdelivr.net/gh/MasonChow/source-map-parser-mcp@main/example/`

## Examples

- Source map address for `bar-special.js`:  
  `https://cdn.jsdelivr.net/gh/MasonChow/source-map-parser-mcp@main/example/special/bar.js.map`

Runtime Example

Error Stack

Uncaught Error: This is a error
    at foo-special.js:49:34832
    at ka (foo-special.js:48:83322)
    at Vs (foo-special.js:48:98013)
    at Et (foo-special.js:48:97897)
    at Vs (foo-special.js:48:98749)
    at Et (foo-special.js:48:97897)
    at Vs (foo-special.js:48:98059)
    at sv (foo-special.js:48:110550)
    at foo-special.js:48:107925
    at MessagePort.Ot (foo-special.js:25:1635)

Runtime Example

FAQ

1. WebAssembly Module Loading Failure

If the tool returns the following error message, please troubleshoot as follows:

parser init error: WebAssembly.instantiate(): invalid value type 'externref', enable with --experimental-wasm-reftypes @+86

Check Node.js Version: Ensure Node.js version is 20 or higher. If it's lower than 20, please upgrade Node.js.
Enable Experimental Flag: If Node.js version is 20+ but you still encounter issues, use the following command to start the tool:
```
npx --node-arg=--experimental-wasm-reftypes -y source-map-parser-mcp@latest
```

Local Development Guide

1. Install Dependencies

Ensure Node.js and npm are installed, then run the following command to install project dependencies:

npm install

2. Link MCP Service

Run the following command to start the MCP server:

npx tsx src/main.ts

Internal Logic Overview

1. Main File Description

stack_parser_js_sdk.js: JavaScript wrapper for the WebAssembly module, providing core stack parsing functionality.
parser.ts: Main implementation of the parser, responsible for initializing the WebAssembly module, retrieving Source Map content, and parsing stack information.
server.ts: Implementation of the MCP server, providing the parse_stack tool interface for external calls.

2. Modify Parsing Logic

To modify the parsing logic, edit the getSourceToken method in the parser.ts file.

3. Add New Tools

In the server.ts file, new tool interfaces can be added using the server.tool method.

Notes

Source Map Files: Ensure that the provided Source Map file address is accessible and the file format is correct.
Error Handling: During parsing, network errors, file format errors, and other issues may be encountered; it's recommended to implement proper error handling when making calls.

Contribution Guidelines

Contributions via Issues and Pull Requests are welcome to improve this project.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Source Map Parser?

Does Source Map Parser need an API key?

What transport does Source Map Parser use?

When was Source Map Parser last checked?

Documentation

Source Map Parser

MCP Integration

Use as an npm package (bring your own MCP server)

Build and Type Declarations

Runtime Parameter Configuration

Feature Overview

MCP Service Tool Description

operating_guide

parse_stack

Request Example

Response Example

lookup_context

Request Example

Response Example

unpack_sources

Request Example

Response Example

Parsing Result Description

Example Run

System Prompt

Runtime Example

FAQ

1. WebAssembly Module Loading Failure

Local Development Guide

1. Install Dependencies

2. Link MCP Service

Internal Logic Overview

1. Main File Description

2. Modify Parsing Logic

3. Add New Tools

Notes

Contribution Guidelines

License

`operating_guide`

`parse_stack`

`lookup_context`

`unpack_sources`