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# 1. Read the newest messages from the event log (oldest first; pass after=evt_... to page forward).
curl -G https://api.flow.engineer/v0/events \
  -H "Authorization: Bearer $FLOW_MESSAGING_KEY" \
  --data-urlencode "type=message.received"

# 2. Reply into the conversation from an event (data[].conversation.id) with a basic message.
curl https://api.flow.engineer/v0/conversations/conv_01JB8ZC3K5M7P9R1T3V5X7Z9B1/basic \
  -H "Authorization: Bearer $FLOW_MESSAGING_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"text": "Hello from my agent"}'

// The Go SDK is not published yet; this is the same agent over plain HTTP,
// standard library only.
package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"os"
	"time"
)

const api = "https://api.flow.engineer"

type event struct {
	ID           string `json:"id"`
	Conversation struct {
		ID string `json:"id"`
	} `json:"conversation"`
	Data struct {
		Message struct {
			Content struct {
				Kind string `json:"kind"` // basic, voice, button_reply, ...
				Text string `json:"text"`
			} `json:"content"`
		} `json:"message"`
	} `json:"data"`
}

func call(method, path string, body any, idempotencyKey string, out any) error {
	var buf bytes.Buffer
	if body != nil {
		if err := json.NewEncoder(&buf).Encode(body); err != nil {
			return err
		}
	}
	req, err := http.NewRequest(method, api+path, &buf)
	if err != nil {
		return err
	}
	req.Header.Set("Authorization", "Bearer "+os.Getenv("FLOW_MESSAGING_KEY"))
	req.Header.Set("Flow-Version", "2026-11-01")
	req.Header.Set("Content-Type", "application/json")
	if idempotencyKey != "" {
		req.Header.Set("Idempotency-Key", idempotencyKey)
	}
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer res.Body.Close()
	if res.StatusCode >= 300 {
		return fmt.Errorf("%s %s: %s", method, path, res.Status)
	}
	if out != nil {
		return json.NewDecoder(res.Body).Decode(out)
	}
	return nil
}

func main() {
	after := ""
	for {
		q := url.Values{"type": {"message.received"}, "limit": {"100"}}
		if after != "" {
			q.Set("after", after)
		}
		var page struct {
			Data    []event `json:"data"`
			HasMore bool    `json:"has_more"`
		}
		if err := call("GET", "/v0/events?"+q.Encode(), nil, "", &page); err != nil {
			fmt.Println(err)
			time.Sleep(2 * time.Second)
			continue
		}
		for _, ev := range page.Data {
			after = ev.ID
			reply := map[string]any{"text": "You said: " + ev.Data.Message.Content.Text}
			if err := call("POST", "/v0/conversations/"+ev.Conversation.ID+"/basic", reply, ev.ID, nil); err != nil {
				fmt.Println(err)
			}
		}
		if !page.HasMore {
			time.Sleep(time.Second)
		}
	}
}