1.9 KiB

Raw Blame History

ST3GG MCP Server — Agent Guide

Overview

ST3GG exposes 13 steganography tools via MCP (stdio transport) for AI agent integration. Covers LSB encoding/decoding, steganalysis, PNG chunk injection, EXIF manipulation, and AI red-team payload construction.

Quick Start

# Run MCP server
uv run --extra mcp python3 mcp_server.py

# Run tests
uv run --extra mcp --with pytest python3 -m pytest tests/test_mcp_server.py -v

Tools

Tool	Purpose
`stegg_encode`	Hide data in image via LSB (15 channel presets, 1-8 bits, 4 strategies, AES-256-GCM)
`stegg_decode`	Extract hidden data (auto-detect or manual config)
`stegg_analyze`	Chi-square anomaly detection with verdict scoring
`stegg_detect`	Quick STEG v3 header check
`stegg_capacity`	Calculate carrier capacity for given settings
`stegg_inject_chunk`	Inject PNG tEXt/zTXt/iTXt/private chunks
`stegg_read_chunks`	Read all PNG chunks and extract text content
`stegg_inject_exif`	Inject EXIF/metadata fields via PIL
`stegg_injection_filename`	Generate prompt-injection filenames for AI red-teaming
`stegg_jailbreak_templates`	List jailbreak prompt template previews
`stegg_analysis_tool`	Run any of 264+ detection functions by name
`stegg_list_analysis_tools`	List all available analysis actions
`stegg_crypto_status`	Check available encryption methods

Known Limitations

Auto-detect only works for interleaved strategy (default). Other strategies require manual config on decode.
spread and randomized strategies have upstream decode bugs in steg_core.py — encode works but decode fails to find the header.
Full analysis mode (stegg_analyze with full=True) is PNG-only.

Error Handling

All tools return JSON. Errors are returned as {"error": "description"} — tools never raise exceptions to the MCP client.

1.9 KiB Raw Blame History