Module agents 

Agent integration module for Sentinel proxy.

This module provides integration with external processing agents for WAF, auth, rate limiting, and custom logic. It implements the SPOE-inspired protocol with bounded behavior and failure isolation.

Architecture

• AgentManager: Coordinates all agents, handles routing to appropriate agents
• Agent: Protocol v1 agent with connection, circuit breaker, and metrics
• AgentV2: Protocol v2 agent with bidirectional streaming and pooling
• AgentConnectionPool: Connection pooling for efficient connection reuse (v1)
• AgentDecision: Combined result from processing through agents
• AgentCallContext: Request context passed to agents

Protocol Versions

• V1: Simple request/response protocol (backwards compatible)
• V2: Bidirectional streaming with capabilities, health reporting, metrics export, and flow control

Queue Isolation

Each agent has its own semaphore for queue isolation, preventing a slow agent from affecting other agents (noisy neighbor problem). Configure concurrency limits per-agent via max_concurrent_calls in the agent configuration.

Example

use sentinel_proxy::agents::{AgentManager, AgentCallContext};

// Each agent manages its own concurrency limit (default: 100)
let manager = AgentManager::new(agent_configs).await?;
manager.initialize().await?;

let decision = manager.process_request_headers(&ctx, headers, &["waf", "auth"]).await?;
if !decision.is_allow() {
    // Handle block/redirect/challenge
}

Structs

Agent

Individual agent configuration and state.

AgentCallContext

Agent call context.

AgentConnectionPool

Agent connection pool for efficient connection reuse.

AgentDecision

Agent decision combining all agent responses.

AgentManager

Agent manager handling all external agents.

AgentMetrics

Agent metrics collector.

AgentV2

Protocol v2 agent with connection pooling and bidirectional streaming.

Enums

AgentAction

Agent action types.