Multi-agent, not monolith. A typed message bus carries every decision. A policy gate sits between every agent and any side effect. The reasoning trace is the product — auditors and investors both read it.
┌──────────────────────────────────────────────────────────────┐
│ Mythal Control Plane │
│ FastAPI · Postgres · Redis · Agent Bus · Policy Gate │
└──────────────────────────────────────────────────────────────┘
▲ ▲
│ │
┌────────┴────────┐ ┌────────┴────────┐
│ Scanner / │ │ Console │
│ Advisory Feeds │ │ (Next.js 15) │
└────────┬────────┘ └─────────────────┘
│
┌────────▼────────┐
│ Rail Simulator │ ← Meridian Continental Railway (MCR)
│ (MCR estate) │
└─────────────────┘Control plane is one FastAPI process today, with background tasks driving the per-finding pipeline. The agent bus is a Postgres-backed signed table plus a Redis pub/sub channel — every message persists before any side effect runs, which is the audit guarantee.
| Rule ID | Name | Decision |
|---|---|---|
SG-POL-001 | CCS requires dual approval + open window + valid rollback | dual_approval or deny |
SG-POL-002 | Any OT-zone asset requires OT Safety Officer sign-off + dual approval | dual_approval |
SG-POL-003 | IT auto-apply — criticality ≤ Medium, reliability ≥ 0.85, canary peer, window open, rollback valid | auto_apply |
SG-POL-004 | Default IT remediation path | single_approval |
SG-POL-005 | No exfiltration to non-allowlisted tools | deny |
SG-POL-006 | Reversibility required — no approval without validated rollback | deny |
SG-POL-007 | Change blackout windows honored | deny |
Python 3.12 · FastAPI · Pydantic v2 · SQLAlchemy 2.0 · Alembic · Celery · Redis · PostgreSQL 16 (Timescale ext) · OpenSearch.
Anthropic Claude (Opus 4.7 / Sonnet 4.6) or OpenAI (o4-mini / gpt-4o-mini). Deterministic fallback always available.
Next.js 15 · TypeScript · SWR · Recharts · react-flow. Three-theme system (CSX · Salesforce · Aurora).
OIDC · Auth0 / Keycloak · SAML SSO · OPA for fine-grained authz · separate OT operator role with dual-approval keys.
Docker · Helm · Kubernetes (EKS / AKS) · Terraform IaC. Optional on-prem appliance via k3s single-VM.
OpenTelemetry · Prometheus · Grafana · Loki. Structured JSON logging mandatory across every agent.
NVD, KEV, vendor PSIRTs, scanner outputs, ticket comments. Wrapped in <untrusted_external> tags in agent prompts. Pre-flight injection classifier flags suspicious patterns.
The Executor agent is the only component permitted to make state-changing calls, and only after the policy gate has approved.
State-changing actions require OT Safety Officer sign-off, dual approval, open maintenance window, AND tested rollback. All four.
Every AgentMessage carries an HMAC-SHA256 signature over canonical JSON. Tampering with the audit ledger is detectable.