Building Networks from Pod Types

The five pod types combine into concrete topology patterns. This page shows how each pattern is structured, which catalog blueprints use it, and what the composition looks like in topology YAML.

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Serial Pipeline

Pattern: Gateway/Initiator → Relay/Processor → Sink/Terminator

flowchart TD
    A["Gateway / Initiator\n(http-gateway)"]
    B["Relay / Processor\n(http-relay)"]
    C["Sink / Terminator\n(http-sink)"]
    A --> B --> C

pods:
  - id: gateway
    template: http-gateway
  - id: middleware
    template: http-relay
  - id: backend
    template: http-sink
connections:
  - from: gateway
    to: middleware
  - from: middleware
    to: backend

Catalog example: Armored Convoy — 3 WoSP units

Use cases: Transformation, enrichment, audit-logging middleware between a trigger point and a result store.

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Fan-In / Aggregation

Pattern: Multiple sources → Aggregator → Sink

flowchart TD
    A["Gateway / Initiator\n(http-gateway)\nsource-a"]
    B["Gateway / Initiator\n(http-gateway)\nsource-b"]
    C["Aggregator\n(http-fan-in)"]
    D["Sink / Terminator\n(http-sink)"]
    A --> C
    B --> C
    C --> D

Catalog example: Armored Trawler — 3 WoSP units

Use cases: Collecting parallel results, scatter/gather patterns, waiting for N upstream events before proceeding.

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Fan-Out / Broadcast

Pattern: Gateway → Distributor/Router → N downstream services

flowchart TD
    A["Gateway / Initiator\n(http-gateway)"]
    B["Distributor / Router\n(http-fan-out)"]
    C["Sink / Terminator\n(http-sink)\nservice-a"]
    D["Sink / Terminator\n(http-sink)\nservice-b"]
    A --> B
    B --> C
    B --> D

Catalog example: Armored Trimaran — 4 WoSP units

Use cases: Broadcast routing, parallel processing dispatch, notifying multiple downstream consumers simultaneously.

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Full Scatter / Gather

Pattern: Gateway → Distributor → N Relays → Aggregator → Sink

flowchart TD
    A["Gateway / Initiator\n(http-gateway)"]
    B["Distributor / Router\n(http-fan-out)"]
    C["Relay / Processor\n(http-relay)\nprocessor-a"]
    D["Relay / Processor\n(http-relay)\nprocessor-b"]
    E["Aggregator\n(http-fan-in)"]
    F["Sink / Terminator\n(http-sink)"]
    A --> B
    B --> C
    B --> D
    C --> E
    D --> E
    E --> F

Catalog example: Armored Carrier — Parallel Processing Cluster — 6 WoSP units

Use cases: Orchestration, parallel task dispatch with result aggregation, map-reduce patterns.

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Cross-Cluster

Pattern: Gateway [Cluster A] → Sink [Cluster B]

flowchart TD
    subgraph ClusterA["Cluster A"]
        A["Gateway / Initiator\n(http-gateway or grpc-gateway)"]
    end
    subgraph ClusterB["Cluster B"]
        B["Sink / Terminator\n(http-sink or grpc-sink)"]
    end
    A -->|"LoadBalancer IP"| B

Cross-cluster connections use LoadBalancer IPs, not Kubernetes DNS. The processor cluster must be deployed first so its LoadBalancer IP is known before the gateway cluster is configured.

Catalog examples: - International Ferry — gRPC, 2 WoSP units - Fast International Ferry — WebSocket, 2 WoSP units

See the Multi-Cluster Guide for setup details.

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AI Agent Network

Pattern: AI Gateway → Orchestrator → LLM + Tool legs → NLP Processor → AI Sink

This is a mixed-protocol blueprint: boundary and orchestration pods use HTTP; the LLM inference and tool execution legs use WebSocket for persistent, low-latency sessions. xtra4 applies AMTD key rotation uniformly across all six legs regardless of protocol.

flowchart TD
    A["AI Gateway / Initiator\n(http-gateway)\nHTTP"]
    B["AI Orchestrator\n(ai-orchestrator)\nHTTP"]
    C["LLM Gateway\n(llm-gateway)\nWebSocket"]
    D["Tool Executor\n(tool-executor)\nWebSocket"]
    E["NLP Processor\n(nlp-processor)\nHTTP"]
    F["AI Results Sink\n(http-sink)\nHTTP"]
    A -->|"HTTP"| B
    B -->|"HTTP"| C
    B -->|"HTTP"| D
    C -->|"WebSocket"| E
    D -->|"WebSocket"| E
    E -->|"HTTP"| F

The ai-orchestrator implements a bounded ReAct loop (MCP-style dispatch). The llm-gateway and tool-executor use WebSocket because LLM streaming responses and real-time tool feedback require persistent connections. All connections are protected by WoSP xtra4 (Armored Tunnel).

Catalog example: Armored Carrier — Zero Trust AI Pipeline — 6 WoSP units

See Mixed-Protocol Blueprints for the full guide to combining protocols in a single network.

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Don't see your topology?

These patterns are the catalog starting point. Any topology composable from the five pod types can be built. Contact lane7@hopr.co with your network requirements.