[DX-883] Addresses message billing docs gap

src/data/nav/chat.ts

@@ -223,6 +223,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'Chat pricing',
+      link: '/docs/chat/pricing',
+    },
     {
       name: 'Guides',
       pages: [

src/data/nav/liveobjects.ts

@@ -55,11 +55,6 @@ export default {
           link: '/docs/liveobjects/concepts/synchronization',
           languages: ['javascript', 'swift', 'java'],
         },
-        {
-          name: 'Billing',
-          link: '/docs/liveobjects/concepts/billing',
-          languages: ['javascript', 'swift', 'java'],
-        },
       ],
     },
     {
@@ -104,6 +99,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'LiveObjects pricing',
+      link: '/docs/liveobjects/pricing',
+    },
   ],
   api: [
     {

src/data/nav/platform.ts

@@ -125,6 +125,10 @@ export default {
           link: '/docs/platform/pricing/billing',
           name: 'Billing',
         },
+        {
+          link: '/docs/platform/pricing/message-counting',
+          name: 'Message counting',
+        },
         {
           link: '/docs/platform/pricing/limits',
           name: 'Limits',

src/data/nav/pubsub.ts

@@ -356,6 +356,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'Pub/Sub pricing',
+      link: '/docs/pub-sub/pricing',
+    },
     {
       name: 'Guides',
       pages: [

src/data/nav/spaces.ts

@@ -57,6 +57,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'Spaces pricing',
+      link: '/docs/spaces/pricing',
+    },
   ],
   api: [
     {

src/pages/docs/chat/pricing.mdx

@@ -0,0 +1,69 @@
+---
+title: "Chat pricing"
+meta_description: "Understand how Chat SDK features contribute to your message count, including messages, typing indicators, reactions, and cost optimization strategies."
+meta_keywords: "chat pricing, message counting, typing indicators, reactions, cost optimization"
+intro: "How Chat SDK features contribute to your message count and strategies to optimize costs."
+redirect_from:
+  - /docs/chat/message-billing
+---
+
+The [Chat SDK](/docs/chat) is built on top of [Pub/Sub](/docs/pub-sub). All Chat operations generate Pub/Sub messages that follow the same counting rules.
+
+<Aside data-type="further-reading">
+For how all Ably products count messages, see [message counting](/docs/platform/pricing/message-counting). For package comparison and volume discounts, see the [pricing](https://ably.com/pricing) page.
+</Aside>
+
+## Chat operations <a id="operations"/>
+
+The following table shows how Chat operations contribute to your message count:
+
+| Operation | Messages counted |
+| --- | --- |
+| [Send message](/docs/chat/rooms/messages) | 1 inbound message |
+| Message delivery | 1 outbound message per subscriber |
+| [Update message](/docs/chat/rooms/messages#update) | 1 inbound message |
+| Message update delivery | 1 outbound message per subscriber |
+| [Delete message](/docs/chat/rooms/messages#delete) | 1 inbound message |
+| Message deletion delivery | 1 outbound message per subscriber |
+| [History](/docs/chat/rooms/history) retrieval | 1 message per retrieved message |
+| [Typing indicator](/docs/chat/rooms/typing) keystroke | 1 inbound message; repeats every heartbeat interval (default 10s) |
+| Typing indicator delivery | 1 outbound message per subscriber per heartbeat |
+| [Typing indicator](/docs/chat/rooms/typing) stop | 1 inbound message |
+| Typing stop delivery | 1 outbound message per subscriber |
+| [Room reaction](/docs/chat/rooms/reactions) | 1 inbound message |
+| Room reaction delivery | 1 outbound message per subscriber |
+| [Message reaction](/docs/chat/rooms/message-reactions) send | 1 inbound message |
+| [Message reaction](/docs/chat/rooms/message-reactions) delete | 1 inbound message |
+| Message reaction summary delivery | 1 outbound message per subscriber; multiple reactions may be rolled up into a single summary |
+| [Presence enter](/docs/chat/rooms/presence) | 1 inbound message |
+| [Presence leave](/docs/chat/rooms/presence) | 1 inbound message |
+| [Presence update](/docs/chat/rooms/presence) | 1 inbound message |
+| Presence event delivery | 1 outbound message per presence subscriber |
+| [Occupancy](/docs/chat/rooms/occupancy) event | 1 outbound message per subscriber (generated on membership changes, debounced up to 15s) |
+| [Moderation](/docs/chat/moderation) action | 1 inbound message; triggers a message update or delete which follows standard delivery |
+
+## Rooms, channels, and connections <a id="rooms-connections"/>
+
+Each Chat room maps to underlying Pub/Sub channels. Each room feature (messages, typing, reactions, presence, occupancy) uses its own channel, contributing to your [channel count](/docs/platform/pricing#channels). Ably bills each connected client for [connection minutes](/docs/platform/pricing#connections) in the same way as Pub/Sub.
+
+## Cost optimization <a id="optimization"/>
+
+### Reduce typing indicator frequency
+
+Increase the `heartbeatThrottleMs` [room option](/docs/chat/rooms#typing) to reduce typing indicator event frequency. The default is 10 seconds. Increase this value in rooms that tolerate delayed typing feedback.
+
+### Disable typing indicators
+
+Disable typing indicators entirely in rooms where they are not needed. This eliminates a significant source of messages, especially in rooms with many participants.
+
+### Use server-side batching
+
+[Server-side batching](/docs/guides/pub-sub/data-streaming#solution-server-side-batching) groups messages into single deliveries. Use this for high-throughput rooms where slight delay is acceptable.
+
+### Use occupancy instead of presence
+
+Use [occupancy](/docs/chat/rooms/occupancy) instead of [presence](/docs/chat/rooms/presence) when you only need member counts, not individual identities. This avoids the n-squared presence event fan-out. For example, 200 members joining and leaving generates approximately **80,400 messages**. See [large-scale presence sets](/docs/presence-occupancy/presence#large-presence) for details.
+
+### Enable server-side presence batching
+
+Enable [server-side batching](/docs/presence-occupancy/presence#large-presence) to group presence events. Subscribe to presence updates only on rooms where you need member-level detail.

src/pages/docs/liveobjects/index.mdx

@@ -96,7 +96,7 @@ LiveObjects [durably stores](/docs/liveobjects/storage) all objects on a channel
 
 LiveObjects usage is billed based on [Ably's standard pricing model](/docs/platform/pricing). Since LiveObjects is powered by Ably's channel messages, any interaction with LiveObjects - whether sending or receiving operations, maintaining active channels, or keeping connections open through the Realtime LiveObjects API - translates into billable usage. Storage of objects themselves does not incur additional costs; however, there is a [limit](/docs/liveobjects/storage) on the size of the channel object.
 
-For details on how using LiveObjects contributes to your billable usage, see [Billing](/docs/liveobjects/concepts/billing).
+For details on how using LiveObjects contributes to your billable usage, see [LiveObjects pricing](/docs/liveobjects/pricing).
 
 ### Realtime API <a id="pricing-realtime"/>
 

src/pages/docs/liveobjects/concepts/billing.mdx → src/pages/docs/liveobjects/pricing.mdx

@@ -1,11 +1,15 @@
 ---
-title: Billing
-meta_description: "Understand how LiveObjects operations contribute to your Ably usage and billing."
+title: "LiveObjects pricing"
+meta_description: "Understand how LiveObjects operations contribute to your message count, including LiveMap, LiveCounter, synchronization, and REST API usage."
+meta_keywords: "LiveObjects pricing, message counting, LiveMap, LiveCounter, ObjectMessages"
+intro: "How LiveObjects operations contribute to your message count."
+redirect_from:
+  - /docs/liveobjects/concepts/billing
 ---
 
 <If lang="javascript">
   <Aside data-type='public-preview'>
-  LiveObjects JavaScript is in Public Preview. We are committed to supporting the LiveObjects Javascript API and welcome adoption and feedback.
+  LiveObjects JavaScript is in Public Preview. Ably is committed to supporting the LiveObjects JavaScript API and welcomes adoption and feedback.
 
   **Building with LiveObjects?** Help shape its future by [sharing your use case](https://44qpp.share.hsforms.com/2fZobHQA1ToyRfB9xqZYQmQ).
   </Aside>
@@ -25,26 +29,38 @@ meta_description: "Understand how LiveObjects operations contribute to your Ably
   </Aside>
 </If>
 
-LiveObjects operations are billed as messages. This page explains how different LiveObjects operations contribute to your Ably usage.
+LiveObjects operations are billed using ObjectMessages. Each ObjectMessage follows the standard inbound/outbound counting pattern.
 
 <Aside data-type="further-reading">
-For general information about Ably pricing and billing, see [Pricing](/docs/platform/pricing).
+For how all Ably products count messages, see [message counting](/docs/platform/pricing/message-counting). For package comparison and volume discounts, see the [pricing](https://ably.com/pricing) page.
 </Aside>
 
-## Message counting <a id="message-counting"/>
+## LiveObjects operations <a id="operations"/>
 
-Each operation is sent as an [`ObjectMessage`](/docs/liveobjects/concepts/operations#properties). Ably bills for each outbound message sent from a client, and for each inbound message delivered to each client.
+The following table shows how LiveObjects operations contribute to your message count:
 
-When a client performs an operation (such as setting a value on a `LiveMap` or incrementing a `LiveCounter`), this generates an outbound message. When that operation is broadcast to other connected clients, each client receives an inbound message.
+| Operation | Messages counted |
+| --- | --- |
+| [LiveMap](#livemap-operations) set or remove | 1 inbound message per operation |
+| [LiveMap](#livemap-operations) create (shallow) | 2 inbound messages (create + assign) |
+| [LiveCounter](#livecounter-operations) increment or decrement | 1 inbound message |
+| [LiveCounter](#livecounter-operations) create | 2 inbound messages (create + assign) |
+| ObjectMessage delivery | 1 outbound message per connected client |
+| [Synchronization](#synchronization) | 1 message per object synchronized |
+| [REST API](#rest-api) fetch | 1 message per object in response |
+| [Batch](#livemap-operations) operation | 1 message per operation in the batch |
 
-For example, if 5 clients are connected to a channel and one client increments a counter:
+Nested object creation generates additional messages for each nested object. See the [examples below](#livemap-operations) for details.
 
-- 1 outbound message (from the client performing the increment)
-- 5 inbound messages (one delivered to each of the 5 connected clients, including the client that sent it)
+## Channels and connections <a id="channels-connections"/>
+
+Each LiveObjects channel contributes to your [channel count](/docs/platform/pricing#channels). Ably bills [connection minutes](/docs/platform/pricing#connections) per minute of connection time for each connected client.
+
+Subscribing to updates does not affect the number of messages received by a client. Any client attached to a channel with the `object-subscribe` capability automatically receives all object messages for that channel. Subscribing to updates on an object adds a listener that is called whenever the client receives updates for that object.
 
 <If lang="javascript">
 
-## LiveMap operations <a id="livemap-operations"/>
+## LiveMap operation examples <a id="livemap-operations"/>
 
 Removing a key and setting a primitive value always sends one message:
 
@@ -100,7 +116,7 @@ await myObject.get('settings').batch((ctx) => {
 ```
 </Code>
 
-## LiveCounter operations <a id="livecounter-operations"/>
+## LiveCounter operation examples <a id="livecounter-operations"/>
 
 Incrementing and decrementing a counter always sends one message:
 
@@ -165,10 +181,6 @@ Similarly, if a client becomes disconnected and needs to resynchronize, it will
 
 Only [reachable](/docs/liveobjects/concepts/objects#reachability) objects are counted. Ably may send [tombstone](/docs/liveobjects/concepts/objects#tombstones) objects to the client, but these will not count towards your usage.
 
-## Subscriptions <a id="subscriptions"/>
-
-Subscribing to updates does not affect the number of messages received by a client. Any client attached to a channel with the `object-subscribe` capability automatically receives all object messages for that channel. Subscribing to updates on an object adds a listener that is called whenever the client receives updates for that object.
-
 ## REST API <a id="rest-api"/>
 
 The [LiveObjects REST API](/docs/liveobjects/rest-api-usage) also counts messages for operations performed.