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The Blueprint: Event-Driven Agentic Gateway with Circuit Breakers

The Blueprint: Event-Driven Agentic Gateway with Circuit Breakers

[User] ──> [API Gateway] ──> [Step Functions Orchestrator] <──> [ElastiCache (Redis)]
                                    │               │
                                    ▼ (Valid Loop)  ▼ (Breaker Tripped)
                             [Bedrock/Agent]    [SNS Alerting] ──> [Slack / On-Call]

Step-by-Step Architectural Data Flow

  1. The Ingress Layer (API Gateway):

    • The user or external system submits an execution request to Amazon API Gateway.
    • API Gateway passes the payload to AWS Step Functions, which serves as your state machine orchestrator (instead of letting code run an unmanaged loop).

  2. The Governance Check (Step Functions + ElastiCache):

    • Before hitting any LLM endpoint, the Step Function executes a validation task via AWS Lambda.
    • This Lambda checks a session state stored in Amazon ElastiCache (Redis).
    • It evaluates two key metrics: Current_Loop_Count and Session_Token_Velocity.

  3. The State Fork (The Decision Point):

    • Path A (Valid Execution): If Loop_Count < 5 and token velocity is below the budget threshold, the Step Function proceeds. It invokes Amazon Bedrock (or your agent runtime Lambda), processes the response, increments the loop counter in Redis, and feeds back into the execution loop.
    • Path B (Breaker Tripped): If the agent gets stuck in a recursive error state and hits Loop_Count >= 5 OR the token velocity spikes, the Step Function immediately exits the loop and triggers the Circuit Breaker State.

  4. The Remediation & Alerting Layer (SNS):

    • Once the breaker trips, the Step Function immediately terminates further execution to freeze your API costs.

    • It moves to a failure state and publishes a structured alert message to Amazon SNS (Simple Notification Service).

    • Amazon SNS routes the alert out to internal engineering teams via a Slack Webhook or PagerDuty stating: CRITICAL: Session ID [X] terminated due to runaway token velocity.

    • The end-user is cleanly returned a deterministic fallback message: “This task requires manual human-in-the-loop review.”