Unit 9 · Connect to external tools and data

Handle long-running MCP work

Modern servers may return a task from an ordinary tool call, which Ax can auto-await or expose for input, cancellation, and observation. Legacy task-draft APIs remain compatibility-only.

11 focused minutesNot started

Worked example

See the idea in context

taskResult, err := client.CallTool("start_reindex", map[string]ax.Value{"scope": "all"})
if err != nil { panic(err) }
taskID := taskResult["task"].(map[string]ax.Value)["taskId"].(string)
target.WaitFor = []map[string]ax.Value{{
    "kind": "mcp.task", "value": "taskKey",
    "metadata": map[string]ax.Value{"taskId": taskID},
}}
runtime.RegisterTarget(target)
runtime.AddSource(started)
runtime.AddSource(mcp)
if err := runtime.Start(); err != nil { panic(err) }
err = started.Publish(ax.AxEventEnvelope{
    SpecVersion: "1.0", ID: "task-start", Source: "app://tasks",
    Type: "app.task.started",
    Data: map[string]ax.Value{
        "taskId": taskID, "taskKey": "inventory:" + taskID,
    },
})
if err != nil { panic(err) }

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/native_mcp_tools.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