[DX-883] Addresses message billing docs gap

src/data/nav/aitransport.ts

@@ -192,6 +192,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'AI Transport pricing',
+      link: '/docs/ai-transport/pricing',
+    },
   ],
   api: [],
 } satisfies NavProduct;

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'],
-        },
       ],
     },
     {
@@ -108,6 +103,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'LiveObjects pricing',
+      link: '/docs/liveobjects/pricing',
+    },
   ],
   api: [
     {

src/data/nav/livesync.ts

@@ -43,6 +43,10 @@ export default {
         },
       ],
     },
+    {
+      name: 'LiveSync pricing',
+      link: '/docs/livesync/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/ai-transport/pricing.mdx

@@ -0,0 +1,39 @@
+---
+title: "AI Transport pricing"
+meta_description: "Understand how AI Transport token streaming contributes to your message count, including per-token and per-response patterns."
+meta_keywords: "AI Transport pricing, message counting, token streaming, message per response, message per token"
+intro: "How AI Transport operations contribute to your message count and strategies to optimize costs."
+---
+
+[AI Transport](/docs/ai-transport) uses standard Pub/Sub messaging. Each token or message published to Ably counts as an inbound message, and each delivery to a subscriber counts as an outbound message.
+
+## AI Transport operations <a id="operations"/>
+
+The following table shows how AI Transport operations contribute to your message count:
+
+| Operation | Messages counted |
+| --- | --- |
+| Token publish (per-token) | 1 inbound message per token |
+| Token publish (per-response with [append rollup](/docs/ai-transport/token-streaming/token-rate-limits#per-response)) | Multiple tokens conflated into fewer inbound messages |
+| Token delivery | 1 outbound message per subscriber |
+| [Persistence](/docs/storage-history/storage) storage | 1 additional message per stored message |
+
+The total cost depends on the [token streaming pattern](/docs/ai-transport/token-streaming#token-streaming-patterns) you choose. With per-token streaming, each token is a separate inbound message. With [message-per-response](/docs/ai-transport/token-streaming/message-per-response), append rollup conflates multiple tokens into fewer inbound messages, reducing costs. For example, 300 tokens can be conflated to approximately 100 inbound messages.
+
+<Aside data-type="further-reading">
+For how all Ably products count messages, see [message counting](/docs/platform/pricing/message-counting).
+</Aside>
+
+## Channels and connections <a id="channels-connections"/>
+
+Each channel used for token streaming contributes to your [channel count](/docs/platform/pricing#channels). Ably bills each connected client for [connection minutes](/docs/platform/pricing#connections) per minute of connection time.
+
+## Cost optimization <a id="optimization"/>
+
+### Use message-per-response streaming
+
+The [message-per-response](/docs/ai-transport/token-streaming/message-per-response) pattern with [append rollup](/docs/ai-transport/token-streaming/token-rate-limits#per-response) conflates multiple tokens into fewer inbound messages, significantly reducing costs compared to per-token streaming.
+
+### Use ephemeral messages
+
+Mark messages as [ephemeral](/docs/pub-sub/advanced#ephemeral) to exempt them from persistence, rewind, resume, and integrations. Use this for streaming tokens where history is not needed.

src/pages/docs/chat/pricing.mdx

@@ -0,0 +1,72 @@
+---
+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."
+---
+
+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.
+
+## Chat operations <a id="operations"/>
+
+The following table shows how Chat operations contribute to your message count:
+
+| Operation | Messages counted |
+| --- | --- |
+| [Messages](/docs/chat/rooms/messages) ||
+| Send message | 1 inbound message |
+| Message delivery | 1 outbound message per subscriber |
+| Update message | 1 inbound message |
+| Message update delivery | 1 outbound message per subscriber |
+| Delete message | 1 inbound message |
+| Message deletion delivery | 1 outbound message per subscriber |
+| [History](/docs/chat/rooms/history) retrieval | 1 message per retrieved message |
+| [Typing indicators](/docs/chat/rooms/typing) ||
+| Typing keystroke | 1 inbound message; repeats every heartbeat interval (default 10s) |
+| Typing indicator delivery | 1 outbound message per subscriber per heartbeat |
+| Typing stop | 1 inbound message |
+| Typing stop delivery | 1 outbound message per subscriber |
+| [Reactions](/docs/chat/rooms/reactions) ||
+| Room reaction | 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](/docs/chat/rooms/presence) and [occupancy](/docs/chat/rooms/occupancy) ||
+| Presence enter | 1 inbound message |
+| Presence leave | 1 inbound message |
+| Presence update | 1 inbound message |
+| Presence event delivery | 1 outbound message per presence subscriber |
+| Occupancy event | 1 outbound message per subscriber (generated on membership changes, debounced up to 15s) |
+| [Moderation](/docs/chat/moderation) ||
+| Moderation action | 1 inbound message; triggers a message update or delete which follows standard delivery |
+
+<Aside data-type="further-reading">
+For how all Ably products count messages, see [message counting](/docs/platform/pricing/message-counting).
+</Aside>
+
+## Rooms, channels, and connections <a id="rooms-connections"/>
+
+Each Chat room maps to a set of underlying Pub/Sub channels. Each room feature (messages, typing, reactions, presence, occupancy) uses its own dedicated channel. The total number of channels used by a room depends on which features are active.
+
+Channels contribute to your [channel count](/docs/platform/pricing#channels). The more rooms a client is attached to, and the more features enabled per room, the more channels are consumed.
+
+Ably bills each connected client for [connection minutes](/docs/platform/pricing#connections). Ably counts a connection-minute for every minute a client maintains an open connection, regardless of activity. Clients that remain connected but idle still accrue connection minutes.
+
+## 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.
+
+### Use server-side batching
+
+[Server-side batching](/docs/messages/batch#server-side) groups messages into single deliveries. Use this for high-throughput rooms where slight delay is acceptable.
+
+### Detach from unused rooms
+
+[Detach](/docs/chat/rooms#detach) from rooms when they are no longer needed, and [release](/docs/chat/rooms#release) rooms that are no longer in use. This reduces your channel count and connection usage. Close connections when the client is done to stop accruing connection minutes.
+
+### 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.

src/pages/docs/liveobjects/index.mdx

@@ -94,7 +94,7 @@ 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"/>