HAR MCP Server

What is HAR MCP Server?

A Model Context Protocol (MCP) server for parsing and analyzing HAR (HTTP Archive) files. It allows AI assistants to inspect network traffic captured in HAR format, with built-in support for redacting sensitive authentication headers.

How to use HAR MCP Server?

Install via Docker, go run, or build from source. Configure the server in your MCP configuration as a stdio-based tool. Use the provided tools: load_har to load a file, list_urls_methods to see all URLs and methods, get_request_ids to find specific request IDs, and get_request_details to retrieve full request details with automatic header redaction.

Key features of HAR MCP Server

• Load HAR files from local filesystem or HTTP URLs
• List all URLs and HTTP methods in a HAR file
• Query request IDs by URL and method combination
• Retrieve full request details with automatic redaction of auth headers
• Handles float/decimal time fields, base64 content, and extra fields
• Supports standard HAR format from browser developer tools

Use cases of HAR MCP Server

• Inspecting network traffic captured by browser developer tools
• Debugging API interactions through AI-assisted analysis
• Auditing authentication and authorization headers in HTTP logs
• Automating HAR file processing in CI/CD pipelines

FAQ from HAR MCP Server

How does HAR MCP Server handle sensitive data?

Authentication headers such as Authorization, X-API-Key, X-Auth-Token, Cookie, Set-Cookie, and Proxy-Authorization are automatically redacted when retrieving request details.

What are the dependencies and runtime requirements?

The server is written in Go. It can run via Docker, go run, or a pre-built binary. It uses martian/har for parsing, mcp-go for MCP implementation, and testify for testing.

How is data loaded into the server?

HAR files are loaded on demand using the load_har tool, either from a local file path or an HTTP/HTTPS URL. Data is not stored permanently between sessions.

What transport does the server use?

The HAR MCP Server runs as a stdio-based MCP server, communicating via JSON‑RPC over standard input/output. It does not support network transports.

How does the server handle non-standard HAR files?

It automatically rounds float/decimal time fields to integers, accepts both plain text and base64‑encoded response content, and tolerates additional fields not present in the basic HAR specification.