Adapters Overview

External World                    NTL Network
─────────────                    ───────────
                  ┌──────────┐
HTTP Request  ──▶ │          │ ──▶ Signal
                  │ Adapter  │
HTTP Response ◀── │          │ ◀── Signal
                  └──────────┘

Chain TX      ──▶ ┌──────────┐ ──▶ Signal
                  │ Adapter  │
Chain Event   ◀── └──────────┘ ◀── Signal

gRPC Call     ──▶ ┌──────────┐ ──▶ Signal
                  │ Adapter  │
gRPC Response ◀── └──────────┘ ◀── Signal

trait Adapter {
    /// Translate an external request into an NTL signal
    fn ingest(&self, external: ExternalPayload) -> Result<Signal>;

    /// Translate an NTL signal into an external response
    fn emit(&self, signal: Signal) -> Result<ExternalPayload>;

    /// The external protocol this adapter speaks
    fn protocol(&self) -> Protocol;

    /// Health check
    fn health(&self) -> AdapterHealth;
}

struct MqttAdapter {
    broker: MqttClient,
    node: NtlNode,
}

impl Adapter for MqttAdapter {
    fn ingest(&self, external: ExternalPayload) -> Result<Signal> {
        let mqtt_msg = MqttMessage::from_bytes(&external.data)?;
        Ok(Signal::data(mqtt_msg.topic)
            .with_payload(mqtt_msg.payload)
            .with_weight(0.5))
    }

    fn emit(&self, signal: Signal) -> Result<ExternalPayload> {
        let topic = signal.signal_type.to_string();
        let payload = signal.payload.to_bytes()?;
        Ok(ExternalPayload::mqtt(topic, payload))
    }

    fn protocol(&self) -> Protocol {
        Protocol::Custom("mqtt".into())
    }

    fn health(&self) -> AdapterHealth {
        AdapterHealth::from(self.broker.is_connected())
    }
}

Existing Mobile App ──HTTP──▶ Web2 Adapter ──Signal──▶ NTL Network
Existing Web App ──GraphQL──▶ Web2 Adapter ──Signal──▶ NTL Network
New AI Agent ────────Signal──▶ NTL Network (native)