Examples

AuditEffectPlugin Scenario

Use an effect scenario to show how a plugin can do side effects without rewriting the main value

AuditEffectPlugin Scenario

Scenario

You want to record an event:

  • a message arrived
  • an action was triggered

but you do not want to:

  • transform the value
  • block the flow

That is a clean effect use case.

Example

import { Agent, BasePlugin, type PluginHooks } from "@downcity/agent";

class AuditEffectPlugin extends BasePlugin {
  readonly name = "audit_effect";
  readonly title = "Audit Effect";
  readonly description = "Writes one audit line for every observed event.";

  readonly hooks: PluginHooks = {
    effect: {
      "audit.observe": [
        async ({ value, plugin }) => {
          console.log(`[${plugin}] observed`, value);
        },
      ],
    },
  };
}

const agent = new Agent({
  id: "repo-helper",
  path: "/path/to/project",
  tools: {},
  plugins: [new AuditEffectPlugin()],
});

await agent.plugins.effect("audit.observe", {
  event: "incoming_message",
  sessionId: "sess_001",
});

Why this is not a pipeline

Because you do not care about returning a new value. The side effect is the whole point.