Powhttp

usestring83stars

MCP server enabling agents to debug HTTP requests better (using powhttp)

1# Powhttp

README.mdMCP server

Transport: stdio
Status: Local

Power your agent

Add this server

Install from the publisher. Not a PlugMCP endpoint.

Run on PlugMCP

Host a copy with our keys and logs.

No packaged release in the registry yet. Follow the repository README.

RepositoryPublisher 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
License: AGPL-3.0
Last checked: 2026-10-27

Stars: 83
Tools: —
Uptime: —

Tools

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

FAQ

Questions

How do I install Powhttp?

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 Powhttp need an API key?

No required environment variable is listed on this record.

What transport does Powhttp use?

Powhttp runs locally over stdio.

When was Powhttp last checked?

Last checked 2026-10-27. MCP server enabling agents to debug HTTP requests better (using powhttp)

From the publisher

Documentation

powhttp-mcp

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

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

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]

Download and install Go from the official website: https://go.dev/doc/install

If you get command not found: powhttp-mcp after installation, you need to add Go's bin directory to your PATH.

Find your Go bin directory:

go env GOPATH

This returns your Go workspace directory, typically ~/go (macOS/Linux) or C:\Users\yourname\go (Windows). The binaries are installed in the bin subdirectory.

macOS / Linux

For bash (~/.bashrc or ~/.bash_profile):

export PATH="$PATH:$(go env GOPATH)/bin"

For zsh (~/.zshrc):

export PATH="$PATH:$(go env GOPATH)/bin"

For fish (~/.config/fish/config.fish):

fish_add_path (go env GOPATH)/bin

Then reload your shell:

source ~/.zshrc  # or ~/.bashrc, etc.

Windows

PowerShell (current session):

$env:PATH += ";$(go env GOPATH)\bin"

Permanently via PowerShell:

[Environment]::SetEnvironmentVariable("PATH", $env:PATH + ";$(go env GOPATH)\bin", "User")

Or via System Settings:

Press Win + R, type sysdm.cpl, press Enter
Go to Advanced → Environment Variables
Under "User variables", select Path and click Edit
Click New and add %USERPROFILE%\go\bin
Click OK to save, then restart your terminal

Enabling the Data API

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

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

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

MCP Prompts

powhttp-mcp provides 4 prompts for guided workflows:

Prompt	Description
`base_prompt`	START HERE: Essential guide for efficient tool usage and token optimization
`compare_browser_program`	Compare browser vs program traffic to find anti-bot detection differences
`build_api_map`	Build an API endpoint catalog from captured traffic
`generate_scraper`	Generate PoC Go scrapers from captured traffic

MCP Tools

powhttp-mcp provides 17 tools for HTTP traffic analysis:

Tool	Description
`powhttp_sessions_list`	List all sessions with entry counts
`powhttp_session_active`	Get the currently active session
`powhttp_search_entries`	Search entries with filters and free text
`powhttp_get_entry`	Get full details of a specific entry
`powhttp_get_tls`	Get TLS handshake events for a connection
`powhttp_get_http2_stream`	Get HTTP/2 frame details for a stream
`powhttp_fingerprint`	Generate HTTP, TLS, and HTTP/2 fingerprints
`powhttp_diff_entries`	Compare two entries to find detection differences
`powhttp_extract_endpoints`	Cluster entries into endpoint groups
`powhttp_describe_endpoint`	Generate detailed endpoint description
`powhttp_trace_flow`	Trace related requests around a seed entry
`powhttp_validate_schema`	Validate entry bodies against a schema
`powhttp_query_body`	Extract specific fields from bodies using JQ expressions
`powhttp_infer_schema`	Infer merged schema from multiple entry bodies with field statistics
`powhttp_graphql_operations`	Cluster GraphQL traffic by operation name and type
`powhttp_graphql_inspect`	Parse and inspect individual GraphQL operations
`powhttp_graphql_errors`	Extract and categorize GraphQL errors from responses

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

Environment Variables

Variable	Description	Default
`POWHTTP_BASE_URL`	Where to find the powhttp API server	`http://localhost:7777`
`POWHTTP_PROXY_URL`	Proxy URL used by prompts when generating scrapers and debugging	`http://127.0.0.1:8890`
`LOG_LEVEL`	How verbose the logs are: `debug`, `info`, `warn`, `error`	`info`
`LOG_FILE`	File to write logs to (empty = print to console)	`""` (console)

Variable	Description	Default
`HTTP_CLIENT_TIMEOUT_MS`	How long to wait for API responses (milliseconds)	`10000` (10s)
`FETCH_WORKERS`	How many entries to fetch in parallel	`16`
`ENTRY_CACHE_MAX_ITEMS`	How many entries to keep in memory cache	`512`
`REFRESH_INTERVAL_MS`	How often to check for new entries (milliseconds)	`2000` (2s)
`REFRESH_TIMEOUT_MS`	Max time for index refresh operation (milliseconds)	`15000` (15s)
`FRESHNESS_THRESHOLD_MS`	Consider data stale after this many milliseconds	`500` (0.5s)

Variable	Description	Default
`TOOL_MAX_BYTES_DEFAULT`	Max response body size tools return (bytes)	`2000000` (2MB)
`RESOURCE_MAX_BODY_BYTES`	Max body size for MCP resources (bytes)	`65536` (64KB)
`TLS_MAX_EVENTS_DEFAULT`	Max TLS handshake events to return	`200`
`H2_MAX_EVENTS_DEFAULT`	Max HTTP/2 frames to return	`200`
`BOOTSTRAP_TAIL_LIMIT`	Max entries to load when starting up	`20000`

Variable	Description	Default
`COMPACT_MAX_ARRAY_ITEMS`	In compact mode, trim arrays to this many items	`3`
`COMPACT_MAX_STRING_LEN`	Truncate strings longer than this (chars)	`500`
`COMPACT_MAX_DEPTH`	Max nesting depth for compaction (0 = unlimited)	`0`
`DEFAULT_SEARCH_LIMIT`	Default max results for search_entries	`10`
`DEFAULT_QUERY_LIMIT`	Default max entries for query_body	`20`
`DEFAULT_CLUSTER_LIMIT`	Default max clusters for extract_endpoints	`15`
`DEFAULT_EXAMPLES_PER_ITEM`	Default examples shown per cluster	`3`

Variable	Description	Default
`LOG_MAX_SIZE_MB`	Rotate log when it reaches this size (MB)	`10`
`LOG_MAX_BACKUPS`	Keep this many old log files	`5`
`LOG_MAX_AGE_DAYS`	Delete log files older than this (days)	`28`
`LOG_COMPRESS`	Compress old log files (`true`/`false`)	`true`

Development

Prerequisites

Go 1.24.5 or later
Running powhttp instance

Building

go build ./cmd/powhttp-mcp

Testing

go test ./...

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

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.

License

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

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

Related Projects

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

Powhttp

usestring83stars

MCP server enabling agents to debug HTTP requests better (using powhttp)

Web Scraping

Install Run on PlugMCP

GitHub

Run on PlugMCP

1# Powhttp

README.mdMCP server

Transport: stdio
Status: Local

Power your agent

Add this server

Install from the publisher. Not a PlugMCP endpoint.

Run on PlugMCP

Host a copy with our keys and logs.

No packaged release in the registry yet. Follow the repository README.

RepositoryPublisher 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
License: AGPL-3.0
Last checked: 2026-10-27

Stars: 83
Tools: —
Uptime: —

Tools

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

FAQ

Questions

How do I install Powhttp?

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 Powhttp need an API key?

No required environment variable is listed on this record.

What transport does Powhttp use?

Powhttp runs locally over stdio.

When was Powhttp last checked?

Last checked 2026-10-27. MCP server enabling agents to debug HTTP requests better (using powhttp)

From the publisher

Documentation

powhttp-mcp

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

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

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]

Download and install Go from the official website: https://go.dev/doc/install

If you get command not found: powhttp-mcp after installation, you need to add Go's bin directory to your PATH.

Find your Go bin directory:

go env GOPATH

This returns your Go workspace directory, typically ~/go (macOS/Linux) or C:\Users\yourname\go (Windows). The binaries are installed in the bin subdirectory.

macOS / Linux

For bash (~/.bashrc or ~/.bash_profile):

export PATH="$PATH:$(go env GOPATH)/bin"

For zsh (~/.zshrc):

export PATH="$PATH:$(go env GOPATH)/bin"

For fish (~/.config/fish/config.fish):

fish_add_path (go env GOPATH)/bin

Then reload your shell:

source ~/.zshrc  # or ~/.bashrc, etc.

Windows

PowerShell (current session):

$env:PATH += ";$(go env GOPATH)\bin"

Permanently via PowerShell:

[Environment]::SetEnvironmentVariable("PATH", $env:PATH + ";$(go env GOPATH)\bin", "User")

Or via System Settings:

Press Win + R, type sysdm.cpl, press Enter
Go to Advanced → Environment Variables
Under "User variables", select Path and click Edit
Click New and add %USERPROFILE%\go\bin
Click OK to save, then restart your terminal

Enabling the Data API

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

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

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

MCP Prompts

powhttp-mcp provides 4 prompts for guided workflows:

Prompt	Description
`base_prompt`	START HERE: Essential guide for efficient tool usage and token optimization
`compare_browser_program`	Compare browser vs program traffic to find anti-bot detection differences
`build_api_map`	Build an API endpoint catalog from captured traffic
`generate_scraper`	Generate PoC Go scrapers from captured traffic

MCP Tools

powhttp-mcp provides 17 tools for HTTP traffic analysis:

Tool	Description
`powhttp_sessions_list`	List all sessions with entry counts
`powhttp_session_active`	Get the currently active session
`powhttp_search_entries`	Search entries with filters and free text
`powhttp_get_entry`	Get full details of a specific entry
`powhttp_get_tls`	Get TLS handshake events for a connection
`powhttp_get_http2_stream`	Get HTTP/2 frame details for a stream
`powhttp_fingerprint`	Generate HTTP, TLS, and HTTP/2 fingerprints
`powhttp_diff_entries`	Compare two entries to find detection differences
`powhttp_extract_endpoints`	Cluster entries into endpoint groups
`powhttp_describe_endpoint`	Generate detailed endpoint description
`powhttp_trace_flow`	Trace related requests around a seed entry
`powhttp_validate_schema`	Validate entry bodies against a schema
`powhttp_query_body`	Extract specific fields from bodies using JQ expressions
`powhttp_infer_schema`	Infer merged schema from multiple entry bodies with field statistics
`powhttp_graphql_operations`	Cluster GraphQL traffic by operation name and type
`powhttp_graphql_inspect`	Parse and inspect individual GraphQL operations
`powhttp_graphql_errors`	Extract and categorize GraphQL errors from responses

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

Environment Variables

Variable	Description	Default
`POWHTTP_BASE_URL`	Where to find the powhttp API server	`http://localhost:7777`
`POWHTTP_PROXY_URL`	Proxy URL used by prompts when generating scrapers and debugging	`http://127.0.0.1:8890`
`LOG_LEVEL`	How verbose the logs are: `debug`, `info`, `warn`, `error`	`info`
`LOG_FILE`	File to write logs to (empty = print to console)	`""` (console)

Variable	Description	Default
`HTTP_CLIENT_TIMEOUT_MS`	How long to wait for API responses (milliseconds)	`10000` (10s)
`FETCH_WORKERS`	How many entries to fetch in parallel	`16`
`ENTRY_CACHE_MAX_ITEMS`	How many entries to keep in memory cache	`512`
`REFRESH_INTERVAL_MS`	How often to check for new entries (milliseconds)	`2000` (2s)
`REFRESH_TIMEOUT_MS`	Max time for index refresh operation (milliseconds)	`15000` (15s)
`FRESHNESS_THRESHOLD_MS`	Consider data stale after this many milliseconds	`500` (0.5s)

Variable	Description	Default
`TOOL_MAX_BYTES_DEFAULT`	Max response body size tools return (bytes)	`2000000` (2MB)
`RESOURCE_MAX_BODY_BYTES`	Max body size for MCP resources (bytes)	`65536` (64KB)
`TLS_MAX_EVENTS_DEFAULT`	Max TLS handshake events to return	`200`
`H2_MAX_EVENTS_DEFAULT`	Max HTTP/2 frames to return	`200`
`BOOTSTRAP_TAIL_LIMIT`	Max entries to load when starting up	`20000`

Variable	Description	Default
`COMPACT_MAX_ARRAY_ITEMS`	In compact mode, trim arrays to this many items	`3`
`COMPACT_MAX_STRING_LEN`	Truncate strings longer than this (chars)	`500`
`COMPACT_MAX_DEPTH`	Max nesting depth for compaction (0 = unlimited)	`0`
`DEFAULT_SEARCH_LIMIT`	Default max results for search_entries	`10`
`DEFAULT_QUERY_LIMIT`	Default max entries for query_body	`20`
`DEFAULT_CLUSTER_LIMIT`	Default max clusters for extract_endpoints	`15`
`DEFAULT_EXAMPLES_PER_ITEM`	Default examples shown per cluster	`3`

Variable	Description	Default
`LOG_MAX_SIZE_MB`	Rotate log when it reaches this size (MB)	`10`
`LOG_MAX_BACKUPS`	Keep this many old log files	`5`
`LOG_MAX_AGE_DAYS`	Delete log files older than this (days)	`28`
`LOG_COMPRESS`	Compress old log files (`true`/`false`)	`true`

Development

Prerequisites

Go 1.24.5 or later
Running powhttp instance

Building

go build ./cmd/powhttp-mcp

Testing

go test ./...

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

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.

License

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

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

Related Projects

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