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

a note from firebase console

Firebase Cloud Messaging tokens have replaced server keys for
sending messages. While you may continue to use them, support
is being deprecated for server keys.

Firebase Cloud Messaging token ( new token )

serverKey variable will also hold the new FCM token by Firebase Cloud Messaging

Firebase Cloud Messaging token can be found in:

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

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

[will be deprecated by firabase as mentioned above!]

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)
	}

}