Firewall AIops

Governed, audited AI-ops for OPNsense and pfSense firewalls — for AI agents (via MCP) and humans (via CLI).

Disclaimer: Community-maintained open-source project. Not affiliated with, endorsed by, or sponsored by the OPNsense project, Deciso, Netgate, or the pfSense project. OPNsense, pfSense and Netgate are trademarks of their respective owners. MIT licensed.

firewall-aiops speaks to two firewall platforms behind one MCP server — OPNsense (REST API under /api/..., API key+secret via HTTP Basic auth) and pfSense (REST API v2 under /api/v2/... from the pfSense-pkg-RESTAPI package, API key via an X-API-Key header) — with the same tools working on both. Each target in the config names its own platform; a name-keyed platform registry selects the API shape (auth + resource paths), so an agent never has to know which firewall it is talking to.

Every tool runs through a built-in governance harness (vendored, zero external dependency): audit log, token/call budget with runaway circuit-breaker, graduated risk-tier approval, undo-token recording, and prompt-injection sanitisation.

Why this exists

• One server, both firewalls — OPNsense and pfSense in a mixed estate, spoken to through identical tool names. Adding a third firewall later is a new platform descriptor, not a rewrite.
• Read the whole firewall — firmware/health, interfaces & gateways, filter rules (with hit counts and state table), NAT (port-forward / outbound / 1:1), aliases, VPN (WireGuard / OpenVPN / IPsec), DHCP leases & reservations, and the firewall log.
• Flagship RCA analyses — transparent heuristics that show their numbers, never a black-box verdict: gateway_health_rca (WAN loss/latency/down → cause + action), rule_hit_and_shadow_analysis (never-hit + shadowed/redundant rules), and blocked_traffic_rca (top blocked sources/ports → scan / brute-force / probe).
• Governed writes — toggle a rule, add/remove an alias entry (reversible, undo-recorded from the fetched before-state), flush states, restart a service, and the "make it live" commit (apply_changes / reconfigure) and reboot at risk=high with a dry-run preview and an approver gate.

Security: read-only mode

This tool is meant to be handed to an AI agent, so its safety story is enforced by the server rather than requested in a prompt:

export FIREWALL_READ_ONLY=1

With that set, the 9 write tools are never registered. An MCP client lists 25 tools instead of 34 — the writes are not hidden, not gated behind a flag, and not merely refused when called. They are absent from the session. A model cannot invoke a tool it was never offered, and cannot be argued into one.

That distinction is the whole point. A tool that exists but refuses still invites retry loops and "I'll describe the call instead" behaviour from smaller models, and it leaves a reviewer trusting a promise. An absent tool is a fact you can check: connect, list the tools, and see that the writes are not there.

Enforcement is two layers deep, so the switch cannot be sidestepped by changing entry point:

Read operations are unaffected, and every call is still audited to ~/.firewall-aiops/audit.db.

The read/write split is derived from each tool's declared risk_level, and a test asserts that this never disagrees with the [READ]/[WRITE] tag in the tool's own documentation — so a write can't quietly present itself as a read.

Running a smaller / local model? See agent-guardrails.md — it lists the guardrails this tool now enforces for you (so you don't spend prompt budget restating them) and gives a ready-made system prompt for what's left.

Tool inventory (34 tools)

Reversible writes record an inverse undo descriptor built from the real fetched before-state (toggle_rule restores the rule's prior enabled flag; alias add/remove invert). apply_changes / reconfigure / reboot are high-risk with dry_run + an approver requirement; reboot is irreversible (audit only).

Install

uv tool install firewall-aiops        # or: pipx install firewall-aiops

Quick start

firewall-aiops init                     # wizard: pick platform (opnsense/pfsense) + store the secret (encrypted)
firewall-aiops doctor                   # verify config, secrets, and connectivity
firewall-aiops overview                 # one-shot: version + gateway/interface health + rule count
firewall-aiops rules list               # list filter rules
firewall-aiops rules toggle <uuid> --disable   # dry-run + double-confirm governed write
firewall-aiops log --action block -n 50 # recent blocked traffic

Run the MCP server (stdio) for an agent:

firewall-aiops mcp                      # or: firewall-aiops-mcp

MCP client config

{
  "mcpServers": {
    "firewall-aiops": {
      "command": "uvx",
      "args": ["--from", "firewall-aiops", "firewall-aiops-mcp"],
      "env": { "FIREWALL_AIOPS_MASTER_PASSWORD": "your-master-password" }
    }
  }
}

Configuration

~/.firewall-aiops/config.yaml (non-secret connection details only):

targets:
  - name: fw1
    platform: opnsense       # opnsense | pfsense
    host: 192.0.2.1
    port: 443
    username: <opnsense-api-key>   # OPNsense API key (unused for pfSense)
    verify_ssl: false        # false for self-signed lab certs
  - name: edge
    platform: pfsense
    host: 192.0.2.2
    verify_ssl: false

The secret — the OPNsense API secret (paired with the key for HTTP Basic auth) or the pfSense API key — is stored encrypted in ~/.firewall-aiops/secrets.enc (Fernet + scrypt-derived key), never plaintext on disk. Set it with firewall-aiops secret set <target> or the init wizard. The store is unlocked by a master password from FIREWALL_AIOPS_MASTER_PASSWORD (non-interactive/MCP/CI) or an interactive prompt (CLI on a TTY). A legacy plaintext env var FIREWALL_<TARGET>_SECRET is honoured as a fallback (migrate with firewall-aiops secret migrate).

Governance

Every MCP tool is wrapped by @governed_tool:

• Audit — every call is logged to ~/.firewall-aiops/audit.db (tool, params with secrets redacted, status, duration, risk tier, approver, rationale).
• Budget / runaway guard — per-process token/call caps and a repeat-call circuit breaker (FIREWALL_MAX_TOOL_CALLS, FIREWALL_RUNAWAY_MAX, …).
• Graduated risk tiers — high-risk writes (apply_changes, reconfigure, reboot) require an approver: set FIREWALL_AUDIT_APPROVED_BY (and FIREWALL_AUDIT_RATIONALE) before they will run.
• Undo recording — reversible writes record an inverse descriptor to ~/.firewall-aiops/undo.db from the fetched before-state (recording only; an external orchestrator executes it).
• Sanitisation — all firewall-returned text is bounded + injection-sanitised before it reaches the agent.

Platform support & verification status

• Platforms: OPNsense (REST API) and pfSense (REST API v2, pfSense-pkg-RESTAPI).
• Test coverage: behaviour is validated against mocked OPNsense/pfSense JSON responses — every module imports, every MCP tool carries the governance marker, the RCA heuristics are unit-tested against synthetic telemetry, and reversible writes are asserted to record the correct inverse undo descriptor. The concrete REST paths are modelled from each project's public API and have not yet been exercised against a live firewall. See docs/VERIFICATION.md for the checklist a live run must satisfy; firewall-aiops doctor (a firmware/version query on both platforms) is the fastest connectivity check. Both platforms are free and self-hostable (OPNsense is fully open-source; pfSense CE is free), so a home lab is the easiest place to run it.
• Missing a capability? Open an issue or PR at github.com/AIops-tools/Firewall-AIops — contributions and feedback welcome.

License

MIT — see LICENSE.