Examples¶

This page provides working examples and configurations for common use cases with MCP Server Fuzzer.

Basic Examples¶

HTTP Transport Examples¶

Basic Tool Fuzzing¶

# Fuzz tools on HTTP server
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 10

# With verbose output
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 10 --verbose

# With custom timeout
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 10 --timeout 60.0

Single Tool Fuzzing¶

# Fuzz only a specific tool
mcp-fuzzer --mode tools --tool analyze_repository --protocol http --endpoint http://localhost:8000 --runs 20

# Fuzz a specific tool with both phases
mcp-fuzzer --mode tools --tool generate_terraform --phase both --protocol http --endpoint http://localhost:8000 --runs 15

Protocol Fuzzing¶

# Fuzz InitializeRequest protocol type
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --protocol http --endpoint http://localhost:8000 --runs-per-type 5

# Fuzz a different protocol type
mcp-fuzzer --mode protocol --protocol-type ProgressNotification --protocol http --endpoint http://localhost:8000

# With verbose output
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --protocol http --endpoint http://localhost:8000 --runs-per-type 5 --verbose

Spec Guard Modes¶

# Run deterministic resource checks
mcp-fuzzer --mode resources --protocol http --endpoint http://localhost:8000 \
  --spec-resource-uri file:///tmp/resource.txt

# Run deterministic prompt checks
mcp-fuzzer --mode prompts --protocol http --endpoint http://localhost:8000 \
  --spec-prompt-name summarize \
  --spec-prompt-args '{"text":"hello"}'

# Run tools + protocol fuzzing with spec checks
mcp-fuzzer --mode all --phase both --protocol http --endpoint http://localhost:8000

SSE Transport Examples¶

Tool Fuzzing with SSE¶

# Basic SSE tool fuzzing
mcp-fuzzer --mode tools --protocol sse --endpoint http://localhost:8000/sse --runs 15

# With realistic data only
mcp-fuzzer --mode tools --phase realistic --protocol sse --endpoint http://localhost:8000/sse --runs 10

# With aggressive data for security testing
mcp-fuzzer --mode tools --phase aggressive --protocol sse --endpoint http://localhost:8000/sse --runs 20

Protocol Fuzzing with SSE¶

# SSE protocol fuzzing
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --protocol sse --endpoint http://localhost:8000/sse --runs-per-type 8

# Fuzz specific protocol type with SSE
mcp-fuzzer --mode protocol --protocol-type CreateMessageRequest --protocol sse --endpoint http://localhost:8000/sse

Stdio Transport Examples¶

Local Process Fuzzing¶

# Fuzz Python script
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10

# Fuzz Node.js server
mcp-fuzzer --mode tools --protocol stdio --endpoint "node server.js" --runs 10

# Fuzz binary executable
mcp-fuzzer --mode tools --protocol stdio --endpoint "./bin/mcp-server" --runs 10

Stdio with Safety System¶

# Enable safety system for stdio
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 --enable-safety-system

# With filesystem sandboxing
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 --enable-safety-system --fs-root /tmp/safe_dir

# Retry with safety on interrupt
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 --retry-with-safety-on-interrupt

Authentication Examples¶

API Key Authentication¶

Configuration File Approach¶

Create auth_config.json:

{
  "providers": {
    "openai_api": {
      "type": "api_key",
      "api_key": "sk-your-openai-api-key",
      "header_name": "Authorization"
    },
    "github_api": {
      "type": "api_key",
      "api_key": "ghp-your-github-token",
      "header_name": "Authorization"
    }
  },
  "tool_mapping": {
    "openai_chat": "openai_api",
    "github_search": "github_api"
  }
}

Use with fuzzer:

mcp-fuzzer --mode tools --auth-config auth_config.json --endpoint http://localhost:8000

Environment Variables Approach¶

export MCP_API_KEY="sk-your-api-key"
export MCP_HEADER_NAME="Authorization"

mcp-fuzzer --mode tools --auth-env --endpoint http://localhost:8000

Basic Authentication¶

export MCP_USERNAME="user"
export MCP_PASSWORD="password"

mcp-fuzzer --mode tools --auth-env --endpoint http://localhost:8000

Safety System Examples¶

Basic Safety Configuration¶

# Enable safety system
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --enable-safety-system

# Set custom filesystem root
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --fs-root /tmp/mcp_fuzzer_safe

# Disable argument-level safety (not recommended)
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --no-safety

Advanced Safety Configuration¶

# Retry with safety on interrupt
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --retry-with-safety-on-interrupt

# Combined safety options
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" \
  --enable-safety-system \
  --fs-root /tmp/safe_dir \
  --retry-with-safety-on-interrupt

Fuzzing Strategy Examples¶

Two-Phase Fuzzing¶

Tool Fuzzing with Both Phases¶

# Run both realistic and aggressive phases
mcp-fuzzer --mode tools --phase both --protocol http --endpoint http://localhost:8000 --runs 15

# Realistic phase only (valid data)
mcp-fuzzer --mode tools --phase realistic --protocol http --endpoint http://localhost:8000 --runs 10

# Aggressive phase only (malicious data)
mcp-fuzzer --mode tools --phase aggressive --protocol http --endpoint http://localhost:8000 --runs 20

Protocol Fuzzing with Both Phases¶

# Two-phase protocol fuzzing
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --phase both --protocol http --endpoint http://localhost:8000 --runs-per-type 10

# Realistic protocol testing
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --phase realistic --protocol http --endpoint http://localhost:8000 --runs-per-type 8

# Aggressive protocol testing
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --phase aggressive --protocol http --endpoint http://localhost:8000 --runs-per-type 15

Configuration Examples¶

Environment Variables Configuration¶

# Core configuration
export MCP_FUZZER_TIMEOUT=60.0
export MCP_FUZZER_LOG_LEVEL=DEBUG
export MCP_FUZZER_SAFETY_ENABLED=true

# Transport-specific configuration
export MCP_FUZZER_HTTP_TIMEOUT=60.0
export MCP_FUZZER_SSE_TIMEOUT=60.0
export MCP_FUZZER_STDIO_TIMEOUT=60.0

# Safety configuration
export MCP_FUZZER_FS_ROOT=~/.mcp_fuzzer

# Run fuzzer
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000

Testing Examples¶

Local Development Testing¶

# Test local HTTP server
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 20 --verbose

# Test local stdio server with safety
mcp-fuzzer --mode tools --protocol stdio --endpoint "python server.py" --runs 10 --enable-safety-system

# Test both modes on local server
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 15
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --protocol http --endpoint http://localhost:8000 --runs-per-type 8

Production-Like Environment Testing¶

# Test with realistic data only
mcp-fuzzer --mode tools --phase realistic --protocol http --endpoint https://api.example.com --runs 10

# Test protocol compliance
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --phase realistic --protocol http --endpoint https://api.example.com --runs-per-type 5

# Test with authentication
mcp-fuzzer --mode tools --phase realistic --protocol http --endpoint https://api.example.com --auth-config auth.json

Security Testing¶

# Aggressive fuzzing for security testing
mcp-fuzzer --mode tools --phase aggressive --protocol http --endpoint http://localhost:8000 --runs 25

# Protocol security testing
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --phase aggressive --protocol http --endpoint http://localhost:8000 --runs-per-type 15

# Combined security testing
mcp-fuzzer --mode tools --phase aggressive --protocol http --endpoint http://localhost:8000 --runs 20
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --phase aggressive --protocol http --endpoint http://localhost:8000 --runs-per-type 10

Reporting Examples¶

Basic Reporting¶

# Generate reports in default 'reports' directory
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10

# Specify custom output directory
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 --output-dir "my_reports"

# Generate comprehensive safety report
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 --safety-report

Advanced Reporting¶

# Export safety data to JSON with custom filename
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 --export-safety-data "safety_data.json"

# Combine all reporting features
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 10 \
    --safety-report \
    --export-safety-data \
    --output-dir "detailed_reports"

Generated Report Files¶

Each fuzzing session creates timestamped reports:

reports/
| -- fuzzing_report_20250812_143000.json    # Complete structured data
| -- fuzzing_report_20250812_143000.txt     # Human-readable summary
| -- safety_report_20250812_143000.json     # Safety system data

Report Content Examples¶

JSON Report Structure¶

{
  "metadata": {
    "session_id": "20250812_143000",
    "start_time": "2025-08-12T14:30:00.123456",
    "mode": "tools",
    "protocol": "stdio",
    "endpoint": "python server.py",
    "runs": 10,
    "fuzzer_version": "1.0.0",
    "end_time": "2025-08-12T14:30:15.654321"
  },
  "tool_results": {
    "test_tool": [
      {"run": 1, "success": true, "args": {...}},
      {"run": 2, "success": false, "exception": "Invalid argument"}
    ]
  },
  "summary": {
    "tools": {
      "total_tools": 1,
      "total_runs": 10,
      "success_rate": 80.0
    }
  }
}

Text Report Example¶

================================================================================
MCP FUZZER REPORT
================================================================================

FUZZING SESSION METADATA
----------------------------------------
session_id: 20250812_143000
start_time: 2025-08-12T14:30:00.123456
mode: tools
protocol: stdio
endpoint: python server.py
runs: 10

SUMMARY STATISTICS
----------------------------------------
Tools Tested: 1
Total Tool Runs: 10
Tools with Errors: 0
Tools with Exceptions: 2
Tool Success Rate: 80.0%

Debugging Examples¶

Verbose Output¶

# Enable verbose logging
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --verbose

# Set specific log level
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --log-level DEBUG

# Combine verbose and log level
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --verbose --log-level DEBUG

Error Handling¶

# Test with increased timeout for slow servers
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --timeout 120.0

# Test with retry mechanism
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --retry-with-safety-on-interrupt

# Test with custom tool timeout
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --tool-timeout 60.0

Output Examples¶

Tool Fuzzer Output¶

+------------------------------------------------------------------------------+
|                              Tool Fuzzer Results                               |
+------------------------------------------------------------------------------+
| Tool Name        | Success Rate | Exception Count | Example Exceptions        |
+------------------------------------------------------------------------------+
| get_weather      | 85.0%        | 3               | Invalid city name        |
| search_web       | 92.0%        | 1               | Network timeout          |
| calculate_math   | 100.0%       | 0               | None                     |
+------------------------------------------------------------------------------+
| Overall          | 92.3%        | 4               | 3 tools tested           |
+------------------------------------------------------------------------------+

Protocol Fuzzer Output¶

+------------------------------------------------------------------------------+
|                           Protocol Fuzzer Results                              |
+------------------------------------------------------------------------------+
| Protocol Type        | Total Runs | Successful | Exceptions | Success Rate |
+------------------------------------------------------------------------------+
| InitializeRequest    | 5          | 5          | 0          | 100.0%       |
| ProgressNotification | 5          | 4          | 1          | 80.0%        |
| CancelNotification   | 5          | 5          | 0          | 100.0%       |
+------------------------------------------------------------------------------+
| Overall              | 15         | 14         | 1          | 93.3%        |
+------------------------------------------------------------------------------+

Enhanced Reporting Examples¶

Comprehensive Safety Reporting¶

# Generate comprehensive safety report
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 20 --safety-report

# Export safety data to JSON
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 20 --export-safety-data

# Combine safety reporting with custom output directory
mcp-fuzzer --mode tools --protocol stdio --endpoint "python test_server.py" --runs 20 \
    --safety-report \
    --export-safety-data \
    --output-dir "detailed_safety_reports"

Performance Examples¶

High-Volume Testing¶

# High-volume tool fuzzing
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 100

# High-volume protocol fuzzing
mcp-fuzzer --mode protocol --protocol-type InitializeRequest --protocol http --endpoint http://localhost:8000 --runs-per-type 50

# Concurrent testing with multiple endpoints
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 50 &
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8001 --runs 50 &
wait

Load Testing¶

# Load test with realistic data
mcp-fuzzer --mode tools --phase realistic --protocol http --endpoint http://localhost:8000 --runs 200

# Load test with aggressive data
mcp-fuzzer --mode tools --phase aggressive --protocol http --endpoint http://localhost:8000 --runs 200

# Monitor performance
mcp-fuzzer --mode tools --protocol http --endpoint http://localhost:8000 --runs 100 --log-level INFO

Summary¶

These examples cover the most common use cases and should help you get started with MCP Server Fuzzer. For more advanced configurations and customizations, refer to the Reference and Architecture documentation.