Reaper MITM Proxy

Reaper is a CLI-based MITM HTTPS proxy for application security testing. It intercepts, logs, and allows inspection of HTTP/HTTPS traffic flowing through it. Use it to capture live request/response pairs for security validation.

Prerequisites

Before using any reaper command, make sure the latest version of the binary is installed:

curl -sfL https://raw.githubusercontent.com/ghostsecurity/reaper/main/scripts/install.sh | bash

All reaper commands in this document should be invoked as ~/.ghost/bin/reaper unless ~/.ghost/bin is on PATH.

Quick Reference

Starting the Proxy

Start reaper scoped to the target domain(s). At least one --domains or --hosts flag is required.

# Intercept all traffic to example.com and its subdomains
reaper start --domains example.com

# Multiple domains
reaper start --domains example.com,api.internal.co

# Exact hostname matching
reaper start --hosts api.example.com

# Both domain suffix and exact host matching
reaper start --domains example.com --hosts special.internal.co

# Custom port (default: 8443)
reaper start --domains example.com --port 9090

# Run as background daemon
reaper start --domains example.com -d

Scope behavior:

• --domains: Suffix match. example.com matches example.com, api.example.com, sub.api.example.com
• --hosts: Exact match. api.example.com matches only api.example.com
• Traffic outside scope passes through transparently without logging

Routing Traffic Through the Proxy

Configure the HTTP client to use the proxy. The default listen address is localhost:8443.

# curl
curl -x http://localhost:8443 -k https://api.example.com/endpoint

# Environment variables (works with many tools)
export http_proxy=http://localhost:8443
export https_proxy=http://localhost:8443

# Python requests
import requests
requests.get("https://api.example.com/endpoint",
             proxies={"http": "http://localhost:8443", "https": "http://localhost:8443"},
             verify=False)

The -k / verify=False flag is needed because reaper generates its own CA certificate at startup for MITM TLS interception.

Viewing Captured Traffic

Recent Entries

# Show last 50 entries (default)
reaper logs

# Show last 200 entries
reaper logs -n 200

Output columns: ID, METHOD, HOST, PATH, STATUS, MS, REQ (request body size), RES (response body size).

Searching

# By HTTP method
reaper search --method POST

# By host (supports * wildcard)
reaper search --host *.api.example.com

# By domain suffix
reaper search --domains example.com

# By path prefix (supports * wildcard)
reaper search --path /api/v3/transfer

# By status code
reaper search --status 200

# Combined filters
reaper search --method POST --path /api/v3/* --status 200 -n 50

Inspecting Individual Entries

# Full request and response (raw HTTP)
reaper get 42

# Request only
reaper req 42

# Response only
reaper res 42

Output is raw HTTP/1.1 format including headers and body, suitable for analysis or replay.

Stopping the Proxy

reaper stop

Common Workflows

Validate a Security Finding

When used with the validate skill (may need to collaborate with the user to setup the test environment):

1. Start reaper scoped to the application domain
2. Verify traffic is being captured by running reaper logs — at least one entry should appear after routing a test request through the proxy
3. If no entries appear, verify proxy settings and domain scope match the target
4. Authenticate (or ask the user to authenticate) as a normal user and exercise the vulnerable endpoint legitimately
5. Search for the captured request to understand the expected request format
6. Craft and send a malicious request that exercises the exploit described in the finding
7. Inspect the response to determine if the exploit succeeded
8. Use reaper get <id> to capture the full request/response as evidence

Data Storage

All data is stored in ~/.reaper/:

• reaper.db – SQLite database with captured entries
• reaper.sock – Unix socket for CLI-to-daemon IPC
• reaper.pid – Daemon process ID

The CA certificate is generated fresh in memory on each start and is not persisted.