API usage restrictions

This page provides a brief overview of the restrictions of the Agora Signaling SDK, including API call limit, string size, encoding, and more.

Unless otherwise specified below, limit the API call frequency by a single client to 20 calls per second. If the number of calls per second exceeds 20, some calls are ignored by the SDK. If you need to call more APIs per second, contact support@agora.io.

Item	Soft limit	Hard limit	Comments
Number of projects in an account	1000	-	To change the limit, contact support@agora.io.
Number of client instances	1	1	Attempts to create multiple instances fail.
Number of message channels per app ID	Unlimited	-	Channel resources are public, users can take them as needed.
Number of stream channels per app ID	Unlimited	-	Channel resources are public, users can take them as needed.
User ID length	64 ASCII characters	64 ASCII characters	Exceeding the soft limit produces an error.

Item	Soft limit	Hard limit	Comments
Message sending rate/client	60 messages/sec	60 messages/sec	Exceeding the soft limit produces an error. To change the limit, contact support@agora.io.
Number of subscribers per channel	Unlimited	-
Number of publishers per channel	Unlimited	-
Number of subscribed channels per client	50	-	Exceeding the soft limit produces an error.
Message packet size	32 KB	32 KB	Exceeding the soft limit produces an error. To change the limit, contact support@agora.io.
Channel name length	64 ASCII characters	64 ASCII characters	Exceeding the soft limit produces an error.
Custom message type length	32 ASCII characters	32 ASCII characters	Exceeding the soft limit produces an error.

Item	Soft limit	Hard limit	Comments
Number of channels a client can create	Unlimited	-
Number of channels a client can join	10	-	A single client can join a maximum of 10 channels simultaneously; exceeding this soft limit results in an error message. To increase the limit, contact support@agora.io.
Number of users per channel	128	128	A single channel can accommodate a maximum of 128 users simultaneously; exceeding this soft limit results in an error message. To increase the limit, contact support@agora.io.
Number of topics per channel	Unlimited	-
Channel name length	64 ASCII characters	64 ASCII characters	Exceeding the soft limit produces an error.

Item	Soft limit	Hard limit	Comments
Number of topics joined by a client in a channel	8	8	Exceeding the soft limit produces an error.
Number of messages published by a client in a topic per second	200 messages/sec	200 messages/sec	Exceeding the soft limit produces an error. To change the limit, contact support@agora.io.
Number of topics subscribed to by a client in a channel	50	50	Exceeding the soft limit produces an error.
Number of users subscribed to a topic by a client	64	64	A single client can subscribe up to 64 user IDs to a single topic. Exceeding the soft limit produces an error.
Number of publishers in a topic	Unlimited	-
Topic name length	16 ASCII characters	16 ASCII characters	The topic name length will be extended to 64 ASCII characters in future releases.
Message packet size	1 KB	1 KB	Exceeding the soft limit produces an error. To change the limit, contact support@agora.io.
Custom message type length	32 ASCII characters	32 ASCII characters	Exceeding the soft limit produces an error.

Item	Soft limit	Hard limit	Comments
Presence timeout	Adjustable range: 5 - 300 seconds Default: 300 seconds	-	When the set timeout value is exceeded, the SDK matches the closest boundary value. For example, if you set presence timeout to 400 seconds, the actual application time is 300 seconds. To change the limit, contact support@agora.io.
Number of temporary user state key/value pairs	32 pairs	32 pairs	Exceeding the soft limit produces an error.
Number of temporary user states cached before joining the channel	100	100	Exceeding the soft limit produces an error.

Item	Soft limit	Hard limit	Comments
Metadata item key length	32 ASCII characters	-
Number of metadata sets per user or channel	1	1	Each channel and each user can only have one set of channel or user metadata, respectively.
Number of items per channel metadata or user metadata set	Unlimited	-
Storage space per channel or user metadata set	16 KB	-	To change the limit, contact support@agora.io.
Storage space per metadata item	16 KB	-	To change the limit, contact support@agora.io.
Channel metadata API call frequency by a single client	10 times/sec	20 times/sec	To change the limit, contact support@agora.io.
User metadata API call frequency by a single client	10 times/sec	20 times/sec	To change the limit, contact support@agora.io.
Number of channel metadata sets per app ID	1 million	-
Number of user metadata sets per app ID	1 million	-	To change the limit, contact support@agora.io.

Item	Soft limit	Hard limit	Comments
Number of locks per channel	32	-	To change the limit, contact support@agora.io.
Number of locked locks per client	Unlimited	-
Lock TTL (Time to live)	10 seconds - 300 seconds	10 seconds - 300 seconds	When a user leaves a channel or disconnects, the lock held by that user is automatically released after the set time. When the set value is exceeded, the SDK matches the closest boundary value. For example, if you set lock TTL to 400 seconds, the actual application time is 300 seconds.
Lock length	64 ASCII characters	64 ASCII characters	Exceeding the soft limit produces an error.
Number of locks per app ID	1 million	-	Exceeding the soft limit produces an error. To change the limit, contact support@agora.io.
Lock acquisition API call frequency	10 times/sec	-

• The number of RESTful API requests per second per app ID are limited to 500. To extend the limit, contact support@agora.io.
• The max number of concurrent users is 50,000. To extend the limit, contact support@agora.io.
• The max number of daily active users is 500,000. To extend the limit, contact support@agora.io.
• The max number of users in a single channel is 50,000. To extend the limit, contact support@agora.io.