re-agent

Autonomous reverse-engineering agent — source-aware reverser/checker loop, objective verifier, parity engine, and Ghidra backend.

Overview

Demo: YouTube

re-agent automates a reverse-engineering workflow by combining a reverser/checker loop with Ghidra decompilation through ghidra-ai-bridge. The current pipeline also retrieves nearby project source context during generation and runs a conservative structural verifier before accepting checker passes.

re-agent reverse --class CTrain
    │
    ├── Config (re-agent.yaml + env + CLI)
    │   └── project_profile (stub_markers, hook_patterns, source_layout)
    │
    ├── Orchestrator (single / class runner)
    │   ├── Function Picker (ranks by caller count, filters completed)
    │   ├── Context Gatherer (decompile + xrefs + structs + source retrieval)
    │   │
    │   ├── Agent Loop (reverser → checker → fix, max N rounds)
    │   │   ├── LLM Providers: Claude | OpenAI-compatible APIs | Codex CLI
    │   │   └── Prompt Templates (customizable .md files)
    │   │
    │   ├── Objective Verifier (call-count + control-flow sanity checks)
    │   │
    │   ├── Parity Engine (GREEN/YELLOW/RED verification gate)
    │   │   ├── Source Indexer (C++ body parser)
    │   │   ├── 11 Heuristic Signals (all configurable/toggleable)
    │   │   └── Semantic Rules + Manual Approvals
    │   │
    │   └── Session State (JSON progress file)
    │
    └── RE Backend: ghidra-ai-bridge
        └── Capability flags → graceful degradation

Requirements

• Python 3.10+
• ghidra-ai-bridge — re-agent uses this as its backend to decompile functions, fetch xrefs, read structs/enums, and query Ghidra. Install it and point it at your Ghidra project before running re-agent reverse.
• One supported LLM setup:
  • ANTHROPIC_API_KEY for Claude
  • OPENAI_API_KEY for OpenAI-compatible APIs
  • a local codex CLI login for the Codex provider

Installation

pip install re-agent

Quick Start

# 1. Initialize project config
re-agent init

# 2. Edit re-agent.yaml with your project settings

# 3. Reverse a single function
re-agent reverse --address 0x6F86A0

# 4. Reverse all functions in a class
re-agent reverse --class CTrain --max-functions 10

# 5. Run parity checks
re-agent parity --address 0x6F86A0

# 6. Check progress
re-agent status

Configuration

re-agent uses a layered configuration system (highest priority first): CLI flags > environment variables (RE_AGENT_*) > re-agent.yaml > defaults.

llm:
  provider: claude           # claude | openai | openai-compat | codex
  model: claude-sonnet-4-5-20250929
  # api_key: set via RE_AGENT_LLM_API_KEY env var
  timeout_s: 1800

backend:
  type: ghidra-bridge
  cli_path: ~/ghidra-tools/ghidra

orchestrator:
  max_review_rounds: 4
  max_functions_per_class: 10
  objective_verifier_enabled: true

project_profile:
  source_root: ./source/game_sa
  hook_patterns:
    - 'RH_ScopedInstall\s*\(\s*(\w+)\s*,\s*(0x[0-9A-Fa-f]+)'
  stub_markers: ["NOTSA_UNREACHABLE"]
  stub_call_prefix: "plugin::Call"

See docs/configuration.md for all options.

CLI Reference

Command	Description
re-agent init	Generate re-agent.yaml config file
re-agent reverse --address ADDR	Reverse a single function
re-agent reverse --class CLASS	Reverse all functions in a class
re-agent reverse --dry-run	Show what would be reversed
re-agent parity --address ADDR	Run parity checks on a function
re-agent parity --filter REGEX	Run parity checks matching pattern
re-agent status	Show reversal progress
re-agent status --class CLASS	Show progress for a specific class

LLM Providers

• Claude (Anthropic SDK) — set ANTHROPIC_API_KEY
• OpenAI / OpenAI-compatible — set OPENAI_API_KEY, optionally set base_url
• Codex CLI — uses local codex exec with ChatGPT login credentials; no API key required

Parity Engine

The parity engine runs 11 configurable heuristic signals to verify reversed code matches the original binary:

Signal	Level	Description
Missing source	RED	No source body found for hooked function
Stub markers	RED	Source contains stub markers (e.g., NOTSA_UNREACHABLE)
Trivial stub	RED	Plugin-call heavy with tiny body and no control flow
Large ASM tiny source	RED	ASM >= 80 instructions but source <= 12 lines
Plugin-call heavy	YELLOW	Plugin calls dominate the function body
Short body	YELLOW	Body has fewer than 6 lines
Low call count	YELLOW	Decompile shows many callees but source has few
FP sensitivity	YELLOW	ASM has floating-point ops but source doesn't
Call count mismatch	YELLOW	Source call count differs significantly from ASM
NaN logic	YELLOW	Decompile has NaN handling but source doesn't
Inline wrapper	INFO	Function is a thin inline wrapper

Objective Verifier

The reversal loop also runs a conservative structural verifier after the LLM checker passes. It only blocks acceptance on strong mismatches such as:

• call-count gaps between candidate code and decompile/ASM
• control-flow gaps where the candidate is clearly missing branches or loops

This is intentionally narrower than full equivalence checking, but it catches obvious false positives before they are recorded as successful reversals.

This matters in practice because an LLM checker can still false-positive on code that looks plausible while missing real branch or call structure from the binary.

Safety

• No auto-commit: re-agent writes code but never commits or pushes
• Bounded retries: Hard cap on fix loop iterations (default: 4)
• Deterministic logs: Every LLM call logged with timestamps
• No destructive ops: Never deletes files, modifies git, or runs builds
• Session isolation: Progress appended, never overwritten

Development

git clone https://github.com/dryxio/auto-re-agent.git
cd auto-re-agent
python -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"

pytest tests/
ruff check src/
mypy src/re_agent/

License

MIT