OpenDefender is a device observability and AI agent enablement platform built on .NET 10. Its primary purpose is to eliminate repetitive manual command execution by giving AI agents structured, read-only visibility into system state — security posture, infrastructure health, reliability, and telemetry — across Linux and Windows through a typed MCP interface.
Rather than granting agents broad shell access, OpenDefender collects, stages, and surfaces system telemetry through well-defined domain boundaries. Each agent role has a clearly scoped view of the data it owns, and all agents are read-only by design.
Effective device monitoring requires constantly running shell commands, correlating outputs, and interpreting trends manually. OpenDefender automates that collection pipeline and surfaces the results through an MCP server so that AI agents (GitHub Copilot, etc.) can answer questions like:
- "Is the disk expected to fill in the next 48 hours?"
- "Are there any firewall rules or open ports that have changed since the last run?"
- "Are all my scheduled backup jobs completing successfully?"
- "Is the system journal at risk of breaching the 180-day retention requirement?"
...without ever running a shell command themselves.
The system has three layers:
┌─────────────────────────────────────────────────────────────┐
│ COLLECTION (DiagnosticOrchestrator) │
│ Runs shell probes: top, free, smartctl, journalctl, etc. │
│ Writes raw metrics → ReportDbContext (SQLite) │
└────────────────────────┬────────────────────────────────────┘
│
┌────────────────────────▼────────────────────────────────────┐
│ STAGING (AnalyticsOrchestrator) │
│ Computes deltas, growth rates, breach flags, gap detection │
│ Writes derived analytics → AnalyticsDbContext (SQLite) │
└────────────────────────┬────────────────────────────────────┘
│
┌────────────────────────▼────────────────────────────────────┐
│ CONSUMPTION (MCP Server + OData API) │
│ Exposes raw + derived data to agents via structured tools │
└─────────────────────────────────────────────────────────────┘
Collection and staging run automatically on startup (if the database is empty) and on a recurring schedule via background hosted services.
OpenDefender is purpose-built to serve four specialized AI agent roles. Each agent has a defined domain, owns a specific subset of MCP tools, and is strictly read-only.
Observes the physical and logical foundation: hardware health, kernel stability, resource utilization, and GPU/accelerator monitoring.
| Tool | Data |
|---|---|
query_resource_metrics |
CPU, memory, disk, swap vs. thresholds |
query_hardware_metrics |
Device health, temperature, SMART attributes |
query_kernel_metrics |
Kernel version, security params, boot metrics |
query_gpu_metrics |
GPU utilization, VRAM, thermals |
query_resource_analytics |
Derived deltas, growth rates, breach detection |
Prompt: infrastructure-health-check
Observes the defensive perimeter: access control, network integrity, firewall posture, and traffic patterns.
| Tool | Data |
|---|---|
query_security_checks |
Firewall state, open ports, severity flags |
query_networking_metrics |
Interface IPs, link state, traffic counters |
query_packet_tracing |
Active captures, anomaly indicators |
query_security_analytics |
Derived breach flags, new issue counts |
Prompt: security-posture-assessment
Observes the continuity posture: backup chain integrity, service stability, scheduled job health, and disaster recovery readiness.
| Tool | Data |
|---|---|
query_data_recovery |
Backup target availability, mount state, size |
query_service_metrics |
Service lifecycle state, uptime |
query_automation_metrics |
Timer/job health, automation results |
query_control_map |
Control layer status, required actions |
query_reliability_analytics |
Derived degradation detection, restart flags |
Prompt: reliability-stability-review
Observes the evidence pipeline: log completeness, retention compliance, shipping health, and coverage gaps.
| Tool | Data |
|---|---|
query_logging_metrics |
Journal disk usage, pipeline component health |
query_logging_inventory |
Log source inventory, types, sizes |
query_ledger_analytics |
Growth trends, retention compliance, gap flags |
Prompt: logging-retention-audit
All agents may cross-reference query_control_map and query_orchestrations to understand the current control-layer status and last collection run.
All agents classify findings consistently:
| Level | Meaning |
|---|---|
| S1 | Critical — immediate action required (e.g. active breach, RPO/RTO at risk, auth logs near loss) |
| S2 | High |
| S3 | Medium |
| S4 | Informational |
src/
├── Library/
│ ├── Application/Services/ # Collectors (DiagnosticOrchestrator, AnalyticsOrchestrator)
│ ├── Database/ # ReportDbContext (raw) + AnalyticsDbContext (derived)
│ ├── Domain/ # Strongly-typed models for all metrics and analytics
│ └── Infrastructure/ # QueryHelper, EF Core helpers
├── Service/
│ ├── Mcp/ # MCP tool + prompt implementations (per agent domain)
│ ├── Controllers/ # OData controllers (raw + analytics routes)
│ ├── Services/ # Background hosted services (collection + retention)
│ └── Program.cs # Startup — Stdio or HTTP transport
├── Cli/ # Manual diagnostic runner
└── Tests/
└── Mcp/ # Agent-level integration tests
.github/
└── agents/
├── open-defneder.core.agent.md # @core agent definition
├── open-defender.shield.agent.md # @shield agent definition
├── open-defender.anchor.agent.md # @anchor agent definition
└── open-defender.ledger.agent.md # @ledger agent definition
- .NET 10 SDK
- Linux (collection probes use Linux system commands)
Ensure TransportType: "Stdio" in src/Service/appsettings.json, then add to .vscode/mcp.json:
{
"mcp": {
"servers": {
"open-defender-dev": {
"type": "stdio",
"command": "dotnet",
"args": [
"run",
"--project",
"${workspaceFolder}/solutions/observability/src/Service/Service.csproj",
"--nologo",
"-v",
"quiet",
"--consoleLoggerParameters:ErrorsOnly"
]
}
}
}
}Install the nuget package from https://www.nuget.org/packages/Rayneforge.OpenDefender/
Once the package is installed globally:
dotnet tool install -g Rayneforge.OpenDefenderYou can add it to your .vscode/mcp.json using the dotnet tool run command (which ensures the correct runtime is used):
{
"mcp": {
"servers": {
"open-defender": {
"type": "stdio",
"command": "dotnet",
"args": ["tool", "run", "rayneforge-opendefender"]
}
}
}
}Alternatively, if rayneforge-opendefender is in your system PATH, you can invoke it directly:
{
"mcp": {
"servers": {
"open-defender": {
"type": "stdio",
"command": "rayneforge-opendefender",
"args": []
}
}
}
}Set TransportType: "Http" and run:
dotnet run --project src/Service/Service.csprojBrowse the intelligence layer directly:
- Raw metrics:
http://localhost:5000/odata/metrics/ResourceMetrics - Derived analytics:
http://localhost:5000/odata/analytics/SecurityAnalytics - Full entity list:
ResourceMetrics,HardwareMetrics,KernelMetrics,GpuMetrics,SecurityChecks,NetworkingMetrics,PacketTracingMetrics,LoggingMetrics,LoggingInventoryMetrics,ServiceMetrics,AutomationMetrics,DataRecoveryMetrics,ControlMap,ResourceAnalytics,SecurityAnalytics,LedgerAnalytics,ReliabilityAnalytics
dotnet run --project src/Cli/Cli.csproj- All agents are read-only. No agent may restart services, modify config, rotate credentials, vacuum logs, or change any system state. They observe and flag only.
- Domains are isolated. Each agent owns its tools. Cross-domain investigations require delegating to the appropriate agent.
- Recommendations are always explicit. When an agent flags an issue, it recommends a specific action — but the owner or an authorized process executes it.
A GitHub Actions workflow builds and packages self-contained executables for Linux and Windows on every push to main.
