Module service 

ServiceActivator trait: metadata & channel binding intent for a service (activator). Service trait: async-only business logic component.

Example

use allora_core::{error::Result, service::Service, Exchange, Message};
#[derive(Debug)] struct Echo;
impl Echo { pub fn new() -> Self { Self } }
#[async_trait::async_trait]
impl Service for Echo {
    async fn process(&self, exchange: &mut Exchange) -> Result<()> {
        if let Some(b) = exchange.in_msg.body_text() { exchange.out_msg = Some(Message::from_text(format!("echo:{b}"))); }
        Ok(())
    }
}
let svc = Echo::new();
let mut ex = Exchange::new(Message::from_text("hi"));
tokio::runtime::Runtime::new().unwrap().block_on(async { svc.process(&mut ex).await.unwrap(); });
assert_eq!(ex.out_msg.unwrap().body_text(), Some("echo:hi"));

Metadata Accessors

• id() – stable identifier (auto-generated or user supplied).
• from() / to() – declared channel ids for wiring.
• ref_name() – reference name matching YAML ref-name and the #[service(name=..)] macro argument (not a file path).

Implementing

use allora::{service::Service, Exchange, error::Result};
struct UppercaseService;
impl UppercaseService { pub fn new() -> Self { Self } }
#[cfg_attr(feature = "async", async_trait::async_trait)]
impl Service for UppercaseService {
    async fn process(&self, exchange: &mut Exchange) -> Result<()> {
        if let Some(body) = exchange.in_msg.body_text() { exchange.in_msg.set_body_text(body.to_uppercase()); }
        Ok(())
    }
}

(Single impl with conditional methods; avoids duplication.)

Future Extensions

• Error classification (e.g. routing vs transformation).
• Lifecycle hooks (init, shutdown).
• Metrics instrumentation via feature flag.

This file intentionally provides only the trait; concrete implementations are user-defined or generated by a future service builder.

Traits

Service

ServiceActivator

Internal metadata describing how a service is wired. Users do NOT implement this directly; it is derived from specs.