go-fcm : FCM Library for Go

Firebase Cloud Messaging ( FCM ) Library using golang ( Go )

This library uses HTTP/JSON Firebase Cloud Messaging connection server protocol

Features

• Send messages to a topic
• Send messages to a device list
• Message can be a notification or data payload
• Supports condition attribute (fcm only)
• Instace Id Features
  • Get info about app Instance
  • Subscribe app Instance to a topic
  • Batch Subscribe/Unsubscribe to/from a topic
  • Create registration tokens for APNs tokens

Usage

go get github.com/NaySoftware/go-fcm

Docs - go-fcm API

https://godoc.org/github.com/NaySoftware/go-fcm

Firebase Cloud Messaging HTTP Protocol Specs

https://firebase.google.com/docs/cloud-messaging/http-server-ref

Firebase Cloud Messaging Developer docs

https://firebase.google.com/docs/cloud-messaging/

(Google) Instance Id Server Reference

https://developers.google.com/instance-id/reference/server

Notes

Server Key

serverKey is the server key by Firebase Cloud Messaging

Server Key can be found in:

1. Firebase project settings
2. Cloud Messaging
3. then copy the server key

Retry mechanism

Retry should be implemented based on the requirements. Sending a request will result with a "FcmResponseStatus" struct, which holds a detailed information based on the Firebase Response, with RetryAfter (response header) if available - with a failed request. its recommended to use a backoff time to retry the request - (if RetryAfter header is not available).

Examples

Send to A topic

package main

import (
	"fmt"
    "github.com/NaySoftware/go-fcm"
)

const (
	 serverKey = "YOUR-KEY"
     topic = "/topics/someTopic"
)

func main() {

	data := map[string]string{
		"msg": "Hello World1",
		"sum": "Happy Day",
	}

	c := fcm.NewFcmClient(serverKey)
	c.NewFcmMsgTo(topic, data)


	status, err := c.Send()


	if err == nil {
    status.PrintResults()
	} else {
		fmt.Println(err)
	}

}

Send to a list of Devices (tokens)

package main

import (
	"fmt"
    "github.com/NaySoftware/go-fcm"
)

const (
	 serverKey = "YOUR-KEY"
)

func main() {

	data := map[string]string{
		"msg": "Hello World1",
		"sum": "Happy Day",
	}

  ids := []string{
      "token1",
  }


  xds := []string{
      "token5",
      "token6",
      "token7",
  }

	c := fcm.NewFcmClient(serverKey)
    c.NewFcmRegIdsMsg(ids, data)
    c.AppendDevices(xds)

	status, err := c.Send()


	if err == nil {
    status.PrintResults()
	} else {
		fmt.Println(err)
	}

}