Architecture

The technical and philosophical framework for engineering amorphous AI.

The Mandrel Project provides a deterministic governance layer for stochastic AI agents. It is designed to “clamp” amorphous agent behaviors to a rigid, machine-readable contract.

Design Philosophy: Engineering the Amorphous

In high-precision manufacturing, a Mandrel provides internal support and defines the shape of a workpiece. Similarly, the Mandrel Project provides the deterministic axis for risk mitigation in agentic systems:

  • The Mandrel Spec: A declarative contract defining an agent’s structural boundaries and risk envelope.
  • The Collet (Sidecar): A high-performance proxy that “clamps” the agent to the spec, ensuring it never slips from security, financial, or data-sovereignty constraints.
  • The Gantry: An automated capability for Agent Lifecycle Management, including sidecar injection and SPIFFE identity provisioning.
  • The Metrology Lab: The Promotion Authority where agents are certified and signed against platform policies and “Golden Datasets” to quantify performance risk. The role it fills is defined as a portable contract, so a deployment can satisfy it with the managed service, a self-hosted lab, or a CI pipeline holding a signing key — see the metrology contract.

Core Architectural Pillars

1. Runtime Mesh (Orchestrator-Specialist)

Mandrel utilizes a decoupled pattern enforced by the Collet sidecar:

  • Orchestrator: Handles intent classification and task delegation.
  • Specialist: An ephemeral, domain-specific worker bound to scoped infrastructure and governed by a specific Mandrel Spec.
  • Model Context Protocol (MCP): The standardized interface used by specialists to interact with enterprise systems (Resources, Prompts, and Tools).

2. Compound Identity (The “Double Badge”)

To prevent privilege escalation and “Identity Wash,” Mandrel mandates a two-factor context:

  • Machine Identity: SPIFFE SVIDs managed by the Gantry.
  • Human Context: User authorization propagated via OIDC and Nested JWTs (RFC 8693).

3. High-Assurance Governance

The architecture ensures a Fail-Closed posture. If the governance layer (Collet, Registry, or IdP) is unreachable or a constraint is ambiguous, the system terminates the action rather than failing-open. This assurance is maintained throughout the agent lifecycle via Continuous Conformance Checks, which periodically re-evaluate promoted agents against “Golden Datasets” to mitigate model and threat drift.

Layered Maturity Model

Agents progress through four operational tiers as they move toward production:

  1. Tier 1: Sandbox (Private): Rapid prototyping using read-only MCP resources.
  2. Tier 2: Trusted (Verified): Agent passes mandrel-check validation; receives a SPIFFE ID; HITL is mandated.
  3. Tier 3: Federated (Discoverable): Spec is published to the Metrology Lab for dynamic discovery by other agents.
  4. Tier 4: Autonomous (Scalable): Advanced features enabled, including Dynamic Client Registration (DCR) and Continuous Access Evaluation (CAE).

Logical Flow

graph TD
    subgraph "User Layer"
        U[Human Operator] -->|Auth| IDP[Identity Provider]
        U -->|Task| ORCH[Orchestrator Agent]
    end

    subgraph "The Mandrel Mesh"
        ORCH -->|Discovery| LAB[(Metrology Lab)]
        ORCH -.->|A2A gRPC| COL[Collet / Specialist]
    end

    subgraph "Governance Control"
        COL -.->|Evaluate| OPA{Open Policy Agent}
        COL -.->|Audit| OTEL[OpenTelemetry]
    end