Ably FAQs

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Ably FAQs

Channels

Channels

Details on channel functionality, limits, and best practices

Can I see messages sent by Channel or ClientID?

Messages

What is the maximum message size?

How do I enable history? My messages are not being stored for longer than a few minutes.

How synchronized / up to date is channel history between datacenters / regions?

How long are messages stored for?

Can a published message be pushed to a mobile device using Mobile Push Notifications (GCM or APN)?

How do I send emojis over Ably

Reliable message ordering for connected clients

Is it possible to prevent messages published being echoed back to the publishing client?

Do you binary encode your messages for greater efficiency?

Can I store my messages for longer?

Can I store messages on specific channels?

Can I send messages between clients without using channels?

Can I send media stream through Ably?

Can I delete messages which have been persisted through the history API?

Can I be notified over HTTP when a channel is created or closed?

Are messages recovered if my connection drops?

Am I able to check who has read published messages?

Is it possible to check if a specific message has been delivered to a device?

Client-specified message ID restrictions for multiple messages published atomically

What is Idempotent Publishing?

Is it possible to check if a specific message has been delivered to a device?

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Subscribing and publishing

Can I attach and subscribe to channels using wildcards?

Is there a maximum number of channels per connection?

How do I subscribe or unsubscribe for messages on channels?

Does an attached channel receive messages even if subscribe has not been called?

Presence

What happens if I exceed the number of members present on a channel?

Can I use webhooks or other rules to maintain an external copy of the presence set of a channel or channels?

Can I change the length of the presence timeout?

How can I see which channels are currently active?

How can I implement presence subscriptions efficiently, in terms of limits?

Why don't presence members leave as soon as I close a tab?

Can a single user be present multiple times on the same channel?

Can I change my connection's clientId after connecting?

What happens to the presence status of a client that abruptly disconnects?

I don't understand why I see so many presence messages in my stats.

Can I be notified over HTTP when someone enters or leaves a channel?

Why do you have a limit on the number of members present on a channel?

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Namespaces and naming

What is a channel namespace and how can I use them?

What restrictions exist for the name field of a channel namespaces?

Are channel names and channel namespaces case-sensitive?

What restrictions are there on channel names?

General

What does it mean if I see 'Channel Region Inactive' in my logs on the Dev Console?

How to limit user numbers in channels/send private messages

What are Channel Mode Flags and how do I use them?

How are channels opened and closed?

History

Can I make a History Call to several Channels Simultaneously?

Occupancy

Can I still use occupancy if the library I am using doesn't yet support channel parameters?