shannon/CLAUDE.md

CLAUDE.md

AI-powered penetration testing agent for defensive security analysis. Automates vulnerability assessment by combining reconnaissance tools with AI-powered code analysis.

Commands

Prerequisites: Docker, Anthropic API key in .env

# Setup
cp .env.example .env && edit .env  # Set ANTHROPIC_API_KEY

# Prepare repo (REPO is a folder name inside ./repos/, not an absolute path)
git clone https://github.com/org/repo.git ./repos/my-repo
# or symlink: ln -s /path/to/existing/repo ./repos/my-repo

# Run
./shannon start URL=<url> REPO=my-repo
./shannon start URL=<url> REPO=my-repo CONFIG=./configs/my-config.yaml

# Monitor
./shannon logs                      # Real-time worker logs
./shannon query ID=<workflow-id>    # Query workflow progress
# Temporal Web UI: http://localhost:8233

# Stop
./shannon stop                      # Preserves workflow data
./shannon stop CLEAN=true           # Full cleanup including volumes

# Build
npm run build

Options: CONFIG=<file> (YAML config), OUTPUT=<path> (default: ./audit-logs/), PIPELINE_TESTING=true (minimal prompts, 10s retries), REBUILD=true (force Docker rebuild), ROUTER=true (multi-model routing via claude-code-router)

Architecture

Core Modules

• src/session-manager.ts — Agent definitions, execution order, parallel groups
• src/ai/claude-executor.ts — Claude Agent SDK integration with retry logic and git checkpoints
• src/config-parser.ts — YAML config parsing with JSON Schema validation
• src/error-handling.ts — Categorized error types (PentestError, ConfigError, NetworkError) with retry logic
• src/tool-checker.ts — Validates external security tool availability before execution
• src/queue-validation.ts — Deliverable validation and agent prerequisites

Temporal Orchestration

Durable workflow orchestration with crash recovery, queryable progress, intelligent retry, and parallel execution (5 concurrent agents in vuln/exploit phases).

• src/temporal/workflows.ts — Main workflow (pentestPipelineWorkflow)
• src/temporal/activities.ts — Activity implementations with heartbeats
• src/temporal/worker.ts — Worker entry point
• src/temporal/client.ts — CLI client for starting workflows
• src/temporal/shared.ts — Types, interfaces, query definitions
• src/temporal/query.ts — Query tool for progress inspection

Five-Phase Pipeline

1. Pre-Recon (pre-recon) — External scans (nmap, subfinder, whatweb) + source code analysis
2. Recon (recon) — Attack surface mapping from initial findings
3. Vulnerability Analysis (5 parallel agents) — injection, xss, auth, authz, ssrf
4. Exploitation (5 parallel agents, conditional) — Exploits confirmed vulnerabilities
5. Reporting (report) — Executive-level security report

Supporting Systems

• Configuration — YAML configs in configs/ with JSON Schema validation (config-schema.json). Supports auth settings, MFA/TOTP, and per-app testing parameters
• Prompts — Per-phase templates in prompts/ with variable substitution ({{TARGET_URL}}, {{CONFIG_CONTEXT}}). Shared partials in prompts/shared/ via prompt-manager.ts
• SDK Integration — Uses @anthropic-ai/claude-agent-sdk with maxTurns: 10_000 and bypassPermissions mode. Playwright MCP for browser automation, TOTP generation via MCP tool. Login flow template at prompts/shared/login-instructions.txt supports form, SSO, API, and basic auth
• Audit System — Crash-safe append-only logging in audit-logs/{hostname}_{sessionId}/. Tracks session metrics, per-agent logs, prompts, and deliverables
• Deliverables — Saved to deliverables/ in the target repo via the save_deliverable MCP tool

Development Notes

Adding a New Agent

1. Define agent in src/session-manager.ts (add to AGENT_QUEUE and parallel group)
2. Create prompt template in prompts/ (e.g., vuln-newtype.txt)
3. Add activity function in src/temporal/activities.ts
4. Register activity in src/temporal/workflows.ts within the appropriate phase

Modifying Prompts

• Variable substitution: {{TARGET_URL}}, {{CONFIG_CONTEXT}}, {{LOGIN_INSTRUCTIONS}}
• Shared partials in prompts/shared/ included via prompt-manager.ts
• Test with PIPELINE_TESTING=true for fast iteration

Key Design Patterns

• Configuration-Driven — YAML configs with JSON Schema validation
• Progressive Analysis — Each phase builds on previous results
• SDK-First — Claude Agent SDK handles autonomous analysis
• Modular Error Handling — Categorized errors with automatic retry (3 attempts per agent)

Security

Defensive security tool only. Use only on systems you own or have explicit permission to test.

Code Style Guidelines

Clarity Over Brevity

• Optimize for readability, not line count — three clear lines beat one dense expression
• Use descriptive names that convey intent
• Prefer explicit logic over clever one-liners

Structure

• Keep functions focused on a single responsibility
• Use early returns and guard clauses instead of deep nesting
• Never use nested ternary operators — use if/else or switch
• Extract complex conditions into well-named boolean variables

TypeScript Conventions

• Use function keyword for top-level functions (not arrow functions)
• Explicit return type annotations on exported/top-level functions
• Prefer readonly for data that shouldn't be mutated

Avoid

• Combining multiple concerns into a single function to "save lines"
• Dense callback chains when sequential logic is clearer
• Sacrificing readability for DRY — some repetition is fine if clearer
• Abstractions for one-time operations

Key Files

Entry Points: src/temporal/workflows.ts, src/temporal/activities.ts, src/temporal/worker.ts, src/temporal/client.ts

Core Logic: src/session-manager.ts, src/ai/claude-executor.ts, src/config-parser.ts, src/audit/

Config: shannon (CLI), docker-compose.yml, configs/, prompts/

Troubleshooting

• "Repository not found" — REPO must be a folder name inside ./repos/, not an absolute path. Clone or symlink your repo there first: ln -s /path/to/repo ./repos/my-repo
• "Temporal not ready" — Wait for health check or docker compose logs temporal
• Worker not processing — Check docker compose ps
• Reset state — ./shannon stop CLEAN=true
• Local apps unreachable — Use host.docker.internal instead of localhost
• Missing tools — Use PIPELINE_TESTING=true to skip nmap/subfinder/whatweb (graceful degradation)
• Container permissions — On Linux, may need sudo for docker commands