System Architecture

ABS Core is a strict Layer 7 API Runtime Enforcement Layer and Identity Access Management (IAM) hub designed specifically for AI Agents and the Model Context Protocol (MCP). It operates by intercepting agent-to-tool communications, evaluating intents, injecting secrets "just-in-time" (JIT), and recording an immutable audit trail.

Unlike standard reverse proxies, ABS Core is optimized for the non-deterministic nature of Large Language Models (LLMs). It decodes natural language parameters and MCP payloads to ensure they match statically defined corporate policies before any high-stakes infrastructure is touched.

System Architecture Overview

graph TD
    subgraph "Agent Runtime"
        Agent[AI Agent]
        Client[LLM SDK / MCP Client]
    end

    subgraph "Runtime Enforcement Layer"
        Runtime Enforcement Layer[ABS Runtime Enforcement Layer Interceptor]
        WASM[Stateless Policy Engine WASM]
        Vault[JIT Credential Vault]
    end

    subgraph "External Infrastructure"
        LLM[Model Provider OpenAI/Anthropic]
        Tools[Production Tools / DBs]
        Ledger[Immutable Audit Ledger]
    end

    Agent --> Client
    Client --> Runtime Enforcement Layer
    Runtime Enforcement Layer --> WASM
    WASM -- "ALLOW (Decrypted)" --> Vault
    WASM -- "DENY (403 Forbidden)" --> Runtime Enforcement Layer
    Vault --> LLM
    Vault --> Tools
    WASM -- "Evidence Hash" --> Ledger

Detailed Execution Flow

sequenceDiagram
    participant Agent
    participant Runtime Enforcement Layer
    participant WASM as WASM Policy Engine
    participant Vault
    participant Tool as Target Tool/DB

    Agent->>Runtime Enforcement Layer: [Intent] API Call (e.g. Drop Table)
    Runtime Enforcement Layer->>WASM: Evaluate Intent Hash + Policy DSL
    Note over WASM: Execution in Isolated Sandbox (<1.2ms)
    WASM-->>Runtime Enforcement Layer: Result: BLOCK (Security Policy violation)
    Runtime Enforcement Layer-->>Agent: 403 Forbidden (Action Intercepted)
    
    rect rgb(240, 240, 240)
    Note right of Tool: Failure path avoided
    end

    Agent->>Gateway: [Intent] Legitimate Query
    Gateway->>WASM: Evaluate
    WASM-->>Gateway: Result: ALLOW
    Gateway->>Vault: Fetch JIT Secret
    Vault->>Tool: Execute with injected Auth
    Tool-->>Agent: Data Return

The Agent Authentication Flow

The standard execution lifecycle of an ABS-governed request operates in a strict, fail-closed loop:

1. Authentication & Attribution: An agent identity (OID) initiates a request targeting an external tool or MCP Server.
2. Payload Interception: The ABS Gateway intercepts the communication at the network or SDK layer.
3. Intent Validation: The sandbox validates the payload against the agent's assigned Compliance Profile (schema validation, scope limits, semantic risk).
4. Secret Injection: If the policy evaluates to ALLOW, ABS Core dynamically injects the required API keys (e.g., Stripe, AWS, GitHub) into the payload. The LLM never holds the keys in its context window.
5. Execution & Auditing: The request is forwarded to the destination. The entire interaction (prompt, intent, decision, timestamp) is cryptographically hashed and appended to an append-only audit log.

Core Components

The architecture avoids complex distributed sidecars in favor of a stateless core evaluated at the edge.

1. The Gateway (Interception Layer)

The Gateway acts as the secure entry point. It can be deployed as an HTTP Proxy overriding the baseURL of major AI SDKs (OpenAI, Anthropic, Vercel AI SDK), or as a middleware within MCP configurations. It guarantees that no unverified payload reaches the application tools.

2. Stateless Policy Engine (WASM - Roadmap)

To minimize latency—the critical enemy of AI UX—ABS Core is architected to utilize WebAssembly (WASM) modules for policy evaluation.

[!NOTE] Status v3.5.0: The current engine uses a high-performance JS-shim for integrity validation. Integration of the native Rust/WASM kernel is scheduled for Q2 2026.

3. JIT Credential Vault

The most critical vulnerability in autonomous systems is credential exfiltration (e.g., prompt injection convincing an LLM to output its database password). ABS Core's vault intercepts the outgoing tool call and injects the necessary authorization headers after validation, ensuring the LLM model never has read access to production secrets.

4. Deterministic Audit Trail

Compliance requires proof. Every decision produced by the Policy Engine generates an event log containing the agent's OID, the evaluation context, the policy version applied, and the outcome (ALLOW/DENY). These logs are hashed sequentially, providing cryptographic proof that the governance layer was not bypassed.

Deployment Topologies

To accommodate different enterprise compliance frameworks, ABS Core supports distinct deployment strategies:

• Cloud/Edge Proxy: The fastest implementation. Traffic is routed through ABS's managed edge network, adding <5ms of overhead to the total LLM roundtrip.
• VPC Self-Hosted Gateway: For organizations with strict data residency requirements (e.g., HIPAA, SOC2, FedRAMP), the gateway can be deployed within the customer's Virtual Private Cloud (AWS, Azure, GCP) using lightweight Docker containers.
• Embedded MCP Middleware: For local or high-security internal agent loops, the runtime can be embedded directly into custom MCP Host implementations.

Security Model

The architecture relies on the principle of Zero Trust for Agents:

1. No Implicit Scope: Every agent starts with zero access rights. Policies explicitly grant access to specific tools, parameters, or domains.
2. Immutable Separation: The evaluation engine (WASM) is isolated from the routing layer. Policies cannot modify the engine, and the engine cannot alter the policies.
3. Fail-Closed Operations: If the policy engine times out, encounters malformed payloads, or detects memory anomalies, the default behavior is to drop the connection and alert the operations team.