Unit 10 · React safely to live events

Resume only the task that owns the event

You let input-required and terminal events resume only their identity-scoped owning continuation. Recorded envelopes make that boundary testable without a live server.

10 focused minutesNot started

Worked example

See the idea in context

target := ax.AxEventTarget{
    ID: "reindex-flow", RetrySafety: "idempotent",
    WaitFor: []map[string]ax.Value{{
        "kind": "mcp.task", "value": "taskKey",
        "metadata": map[string]ax.Value{"taskId": taskID},
    }},
    MapInput: func(event ax.AxEventEnvelope, continuation *ax.AxEventContinuation) (ax.Value, error) {
        if continuation != nil {
            return map[string]ax.Value{"taskId": continuation.Metadata["taskId"]}, nil
        }
        return map[string]ax.Value{"taskId": event.Data.(map[string]ax.Value)["taskId"]}, nil
    },
    Invoke: invokeFlow,
}
routes := []ax.AxEventRoute{
    {ID: "task-start", Action: "wake", TargetID: "reindex-flow", Match: map[string]ax.Value{"types": ax.Array("app.task.started")}},
    {ID: "task-resume", Action: "resume", TargetID: "reindex-flow", Match: map[string]ax.Value{"types": ax.Array("mcp.task.status")}},
}

Run itIn your own project

go get github.com/ax-llm/ax/packages/go

package main

import (
    "context"
    "fmt"
    "os"

    axllm "github.com/ax-llm/ax/packages/go"
)

func main() {
    client := axllm.NewAI("openai", map[string]axllm.Value{"apiKey": os.Getenv("OPENAI_API_KEY")})
    classify := axllm.NewAx("review:string -> sentiment:class \"positive, negative, neutral\"", nil)
    result, err := classify.Forward(context.Background(), client, map[string]axllm.Value{
        "review": "Useful and boring in the best way."
    }, nil)
    if err != nil {
        panic(err)
    }

    fmt.Println("sentiment:", result.(map[string]axllm.Value)["sentiment"])
}

Set OPENAI_APIKEY in your environment before running provider-backed code.

In the ax repo

From a clone of the ax repo:

npm run example -- go src/examples/go/mcp/resource_wake_agent.go

Active practice

Show that you can use it

Answer 2 in a row to learn this · attempt 1

Keep exploring

See the idea in context

Show that you can use it

Source-backed follow-up