powhttp-mcp

An MCP server that gives AI assistants X-ray vision into HTTP traffic captured by powhttp.

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See it in action

Using /generate_scraper to build a BMW car listing monitor:

https://github.com/user-attachments/assets/be098e9d-d700-491c-ae7f-5afb12732728

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Features

• HTTP Traffic Analysis - Search, inspect, and analyze captured HTTP requests/responses
• Anti-Bot Detection - Compare browser vs program traffic to identify detection vectors
• Fingerprinting - Generate TLS (JA3/JA4) and HTTP/2 fingerprints
• API Mapping - Cluster and catalog API endpoints from captured traffic
• GraphQL Analysis - Cluster operations, inspect schemas, and extract errors from GraphQL APIs
• Schema Inference - Infer merged schemas from multiple response bodies with field statistics
• Flow Tracing - Trace related requests (redirects, dependent calls)
• Schema Validation - Validate response bodies against Go structs, Zod, or JSON Schema
• Scraper Generation - Generate PoC Go scrapers from captured traffic

Schema validation in action - correcting data structures for edge cases:

https://github.com/user-attachments/assets/1156c537-70ab-4179-ad4a-c148988ac503

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Installation

Install via go install:

go install github.com/usestring/powhttp-mcp/cmd/powhttp-mcp@latest

Or install a specific version:

go install github.com/usestring/powhttp-mcp/cmd/[email protected]

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Enabling the Data API

Before using powhttp-mcp, you need to enable the Data API in powhttp:

1. Open Powhttp Settings > Data API
2. Make sure the Data API is running
3. (Recommended) Enable Auto start on app launch for convenience
4. Note the port number — you’ll need this for POWHTTP_BASE_URL in your MCP configuration

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Usage

Connecting to Cursor

Add to your .cursor/mcp.json:

{
  "mcpServers": {
    "powhttp": {
      "command": "powhttp-mcp",
      "env": {
        "POWHTTP_BASE_URL": "http://localhost:7777",
        "POWHTTP_PROXY_URL": "http://localhost:8888"
      }
    }
  }
}

Connecting to Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "powhttp": {
      "command": "powhttp-mcp",
      "env": {
        "POWHTTP_BASE_URL": "http://localhost:7777",
        "POWHTTP_PROXY_URL": "http://localhost:8888"
      }
    }
  }
}

Connecting to Claude Code

Add using the CLI:

claude mcp add powhttp -e POWHTTP_BASE_URL=http://localhost:7777 -e POWHTTP_PROXY_URL=http://localhost:8888 -- powhttp-mcp

The generated scraper running successfully:

https://github.com/user-attachments/assets/52b30cbf-7c66-40b1-a3fe-9c12d37ece11

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MCP Prompts

powhttp-mcp provides 4 prompts for guided workflows:

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MCP Tools

powhttp-mcp provides 17 tools for HTTP traffic analysis:

See internal/mcp/README.md for detailed tool documentation.

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Environment Variables

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Development

Prerequisites

• Go 1.24.5 or later
• Running powhttp instance

Building

go build ./cmd/powhttp-mcp

Testing

go test ./...

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Feature Requests & Bug Reports

Have a feature suggestion or found a bug? We’d love to hear from you!

• Feature Requests: Open an issue with the enhancement label
• Bug Reports: Please include steps to reproduce, your environment details, and relevant logs

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Contributing

We use squash merges for all pull requests. When creating a PR, ensure the PR title follows Conventional Commits format, as it will become the commit message:

Triggers release:

• feat: - minor version bump
• fix: - patch version bump
• perf: - patch version bump
• revert: - patch version bump
• feat!: or BREAKING CHANGE: - major version bump

No release:

• docs:, chore:, refactor:, test:, style:, build:, ci:

Versioning is automated via release-please.

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License

This project is licensed under the GNU Affero General Public License v3.0 - see the LICENSE file for details.

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Acknowledgments

About String — String ( better website coming soon :) ) extracts structured data from any website at scale. We handle all the code and maintenance.

This project was built during an internal hackathon focused on developer experience tooling. Special thanks to:

• Kashif Ghafoor — For his contributions during the hackathon
• Florian — Creator of powhttp for implementing the API from a suggestion and being responsive to feedback

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Related Projects

• powhttp - HTTP traffic capture and analysis
• Model Context Protocol - Protocol specification