You can send messages to devices that are subscribed to a particular topic using the Admin SDK or the FCM v1 HTTP API.
Prerequisites
-
Set up the necessary environment for sending messages using your chosen method. See Set Up Your Server Environment .
-
Client apps must be subscribed to the topic. See Manage Topic Subscriptions .
Sending to a Topic
You can send messages to a topic using either the Firebase Admin SDK or the FCM HTTP v1 API.
Using the Admin SDK
You can use the Admin SDK to send topic messages from your server. To learn more about setting up the Admin SDK, see Send Messages using the Admin SDK .
Node.js
// The topic name can be optionally prefixed with "/topics/".
const
topic
=
'highScores'
;
const
message
=
{
data
:
{
score
:
'850'
,
time
:
'2:45'
},
topic
:
topic
};
// Send a message to devices subscribed to the provided topic.
getMessaging
().
send
(
message
)
.
then
((
response
)
=
>
{
// Response is a message ID string.
console
.
log
(
'Successfully sent message:'
,
response
);
})
.
catch
((
error
)
=
>
{
console
.
log
(
'Error sending message:'
,
error
);
});
Java
// The topic name can be optionally prefixed with "/topics/".
String
topic
=
"highScores"
;
// See documentation on defining a message payload.
Message
message
=
Message
.
builder
()
.
putData
(
"score"
,
"850"
)
.
putData
(
"time"
,
"2:45"
)
.
setTopic
(
topic
)
.
build
();
// Send a message to the devices subscribed to the provided topic.
String
response
=
FirebaseMessaging
.
getInstance
().
send
(
message
);
// Response is a message ID string.
System
.
out
.
println
(
"Successfully sent message: "
+
response
);
Python
# The topic name can be optionally prefixed with "/topics/".
topic
=
'highScores'
# See documentation on defining a message payload.
message
=
messaging
.
Message
(
data
=
{
'score'
:
'850'
,
'time'
:
'2:45'
,
},
topic
=
topic
,
)
# Send a message to the devices subscribed to the provided topic.
response
=
messaging
.
send
(
message
)
# Response is a message ID string.
print
(
'Successfully sent message:'
,
response
)
Go
// The topic name can be optionally prefixed with "/topics/".
topic
:=
"highScores"
// See documentation on defining a message payload.
message
:=
& messaging
.
Message
{
Data
:
map
[
string
]
string
{
"score"
:
"850"
,
"time"
:
"2:45"
,
},
Topic
:
topic
,
}
// Send a message to the devices subscribed to the provided topic.
response
,
err
:=
client
.
Send
(
ctx
,
message
)
if
err
!=
nil
{
log
.
Fatalln
(
err
)
}
// Response is a message ID string.
fmt
.
Println
(
"Successfully sent message:"
,
response
)
C#
// The topic name can be optionally prefixed with "/topics/".
var
topic
=
"highScores"
;
// See documentation on defining a message payload.
var
message
=
new
Message
()
{
Data
=
new
Dictionary<string
,
string
> ()
{
{
"score"
,
"850"
},
{
"time"
,
"2:45"
},
},
Topic
=
topic
,
};
// Send a message to the devices subscribed to the provided topic.
string
response
=
await
FirebaseMessaging
.
DefaultInstance
.
SendAsync
(
message
);
// Response is a message ID string.
Console
.
WriteLine
(
"Successfully sent message: "
+
response
);
Using the HTTP v1 API
To send topic messages using the HTTP v1 API, construct a JSON POST request. To learn more about using the HTTP v1 API, see Send a Message via FCM v1 API .
REST
POST https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
Content-Type: application/json
Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA
{
"message":{
"topic" : "foo-bar",
"notification" : {
"body" : "This is a Firebase Cloud Messaging Topic Message!",
"title" : "FCM Message"
}
}
}
cURL command:
curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
"message": {
"topic" : "foo-bar",
"notification": {
"body": "This is a Firebase Cloud Messaging Topic Message!",
"title": "FCM Message"
}
}
}' https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
Sending to Topic Conditions
To send a message to a combination
of topics, specify a condition
, which is
a boolean expression that specifies the target topics. For example, the
following condition will send messages to devices that are subscribed to TopicA
and either TopicB
or TopicC
:
"'TopicA' in topics && ('TopicB' in topics || 'TopicC' in topics)"
FCM first evaluates any conditions in parentheses, and then evaluates the expression from left to right. You can include up to five topics in your conditional expression.
Using the Admin SDK
Node.js
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
const
condition
=
'\'stock-GOOG\' in topics || \'industry-tech\' in topics'
;
// See documentation on defining a message payload.
const
message
=
{
notification
:
{
title
:
'$FooCorp up 1.43% on the day'
,
body
:
'$FooCorp gained 11.80 points to close at 835.67, up 1.43% on the day.'
},
condition
:
condition
};
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
getMessaging
().
send
(
message
)
.
then
((
response
)
=
>
{
// Response is a message ID string.
console
.
log
(
'Successfully sent message:'
,
response
);
})
.
catch
((
error
)
=
>
{
console
.
log
(
'Error sending message:'
,
error
);
});
Java
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
String
condition
=
"'stock-GOOG' in topics || 'industry-tech' in topics"
;
// See documentation on defining a message payload.
Message
message
=
Message
.
builder
()
.
setNotification
(
Notification
.
builder
()
.
setTitle
(
"$GOOG up 1.43% on the day"
)
.
setBody
(
"$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day."
)
.
build
())
.
setCondition
(
condition
)
.
build
();
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
String
response
=
FirebaseMessaging
.
getInstance
().
send
(
message
);
// Response is a message ID string.
System
.
out
.
println
(
"Successfully sent message: "
+
response
);
Python
# Define a condition which will send to devices which are subscribed
# to either the Google stock or the tech industry topics.
condition
=
"'stock-GOOG' in topics || 'industry-tech' in topics"
# See documentation on defining a message payload.
message
=
messaging
.
Message
(
notification
=
messaging
.
Notification
(
title
=
'$GOOG up 1.43
% o
n the day'
,
body
=
'$GOOG gained 11.80 points to close at 835.67, up 1.43
% o
n the day.'
,
),
condition
=
condition
,
)
# Send a message to devices subscribed to the combination of topics
# specified by the provided condition.
response
=
messaging
.
send
(
message
)
# Response is a message ID string.
print
(
'Successfully sent message:'
,
response
)
Go
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
condition
:=
"'stock-GOOG' in topics || 'industry-tech' in topics"
// See documentation on defining a message payload.
message
:=
& messaging
.
Message
{
Data
:
map
[
string
]
string
{
"score"
:
"850"
,
"time"
:
"2:45"
,
},
Condition
:
condition
,
}
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
response
,
err
:=
client
.
Send
(
ctx
,
message
)
if
err
!=
nil
{
log
.
Fatalln
(
err
)
}
// Response is a message ID string.
fmt
.
Println
(
"Successfully sent message:"
,
response
)
C#
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
var
condition
=
"'stock-GOOG' in topics || 'industry-tech' in topics"
;
// See documentation on defining a message payload.
var
message
=
new
Message
()
{
Notification
=
new
Notification
()
{
Title
=
"$GOOG up 1.43% on the day"
,
Body
=
"$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day."
,
},
Condition
=
condition
,
};
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
string
response
=
await
FirebaseMessaging
.
DefaultInstance
.
SendAsync
(
message
);
// Response is a message ID string.
Console
.
WriteLine
(
"Successfully sent message: "
+
response
);
Using the HTTP v1 API
REST
POST https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
Content-Type: application/json
Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA
{
"message":{
"condition": "'dogs' in topics || 'cats' in topics",
"notification" : {
"body" : "This is a Firebase Cloud Messaging Topic Message!",
"title" : "FCM Message",
}
}
}
cURL command:
curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
"notification": {
"title": "FCM Message",
"body": "This is a Firebase Cloud Messaging Topic Message!",
},
"condition": "'dogs' in topics || 'cats' in topics"
}' https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
Handling Topic Messages in the App
Once you send a message to a topic, FCM delivers it to all subscribed client app instances.
To learn how to receive and process messages in your Android, iOS, or Web app, see Receive Messages .
