AIT-149: Add pricing information to docs

src/pages/docs/ai-transport/index.mdx

@@ -134,4 +134,13 @@ Take a look at some example code running in-browser of the sorts of features you
 
 ## Pricing
 
-// Todo
+AI Transport uses Ably's [usage based billing model](/docs/platform/pricing) at your package rates. Your consumption costs will depend on the number of messages inbound (published to Ably) and outbound (delivered to subscribers), and how long channels or connections are active. [Contact Ably](https://ably.com/contact) to discuss options for Enterprise pricing and volume discounts.
+
+The cost of streaming token responses over Ably depends on:
+
+- the number of tokens in the LLM responses that you are streaming. For example, a simple support chatbot response is around 300 tokens, a code session chat can be 2,000-3,000 tokens and a deep reasoning response could be over 50,000 tokens.
+- the rate at which your agent publishes tokens to Ably and the number of messages it uses to do so. Some LLMs output every token as a single event, while others batch multiple tokens together. Similarly, your agent may publish tokens as they are received from the LLM or perform its own processing and batching first.
+- the number of subscribers receiving the response.
+- the [token streaming pattern](/docs/ai-transport/features/token-streaming#token-streaming-patterns) you choose.
+
+For example, an AI support chatbot sending a response of 250 tokens at 70 tokens/s to a single client using the [message-per-response](/docs/ai-transport/features/token-streaming/message-per-response) pattern would consume 90 inbound messages, 90 outbound messages and 90 persisted messages. See the [AI support chatbot pricing example](/docs/platform/pricing/examples/ai-chatbot) for a full breakdown of the costs in this scenario.

src/pages/docs/platform/pricing/examples/ai-chatbot.mdx

@@ -0,0 +1,57 @@
+---
+title: AI support chatbot
+meta_description: "Calculate AI Transport pricing for conversations with an AI chatbot. Example shows how using the message-per-response pattern and modifying the append rollup window can generate cost savings."
+meta_keywords: "chatbot, support chat, token streaming, token cost, AI Transport pricing, Ably AI Transport pricing, stream cost, Pub/Sub pricing, realtime data delivery, Ably Pub/Sub pricing"
+intro: "This example uses consumption-based pricing for an AI support chatbot use case, where a single agent is publishing tokens to user over AI Transport."
+---
+
+### Assumptions
+
+The scale and features used in this calculation.
+
+| Scale | Features |
+|-------|----------|
+| 4 user prompts to get to resolution | ✓ Message-per-response |
+| 250 tokens per LLM response | |
+| 70 appends per second from agent | |
+| 3 minute average chat duration | |
+| 1 million chats | |
+
+### Cost summary
+
+The high level cost breakdown for this scenario. Messages are billed for both inbound (published to Ably) and outbound (delivered to subscribers). Creating the "Message updates and deletes" [channel rule](/docs/ai-transport/features/token-streaming/message-per-response#enable) will automatically enable message persistence.
+
+| Item | Calculation | Cost |
+|------|-------------|------|
+| Messages | 1092M × $2.50/M | $2730.00 |
+| Connection minutes | 6M × $1.00/M | $6.00 |
+| Channel minutes | 3M × $1.00/M | $3.00 |
+| Package fee |  | [See plans](/pricing) |
+| **Total** |  | **~$2739.00/M chats** |
+
+### Message breakdown
+
+How the message cost breaks down. The message-per-response pattern includes [automatic rollup of append events](/docs/ai-transport/features/token-streaming/token-rate-limits#per-response) to reduce consumption costs and avoid rate limits.
+
+| Type | Calculation | Inbound | Outbound | Total messages | Cost |
+|------|-------------|---------|----------|----------------|------|
+| User prompts | 1M chats × 4 prompts | 4M | 4M | 8M | $20.00 |
+| Agent responses | 1M chats x 4 responses x 250 token events per response | 360M | 360M | 720M | $1800.00 |
+| Persisted messages | Every inbound message is persisted | 364M | 0 | 364M | $910.00 |
+
+### Effect of append rollup
+
+The calculation above uses the default append rollup window of 40ms, chosen to control costs with minimum impact on responsiveness. For a text chatbot use case, you could increase the window to 200ms without noticably impacting the user experience.
+
+| Rollup window | Inbound response messages | Total messages | Cost |
+|---------------|---------------------------|----------------|------|
+| 40ms | 360 per chat | 1092M | $2730.00/M chats |
+| 100ms | 144 per chat | 444M | $1110.00/M chats |
+| 200ms | 72 per chat | 228M | $570.00/M chats |
+
+<Aside data-type='further-reading'>
+- [Talk with our sales team](https://ably.com/contact) to get a personalised quote.
+- [Learn how HubSpot uses Ably to enable 128,000 businesses with live chat that just works](https://ably.com/case-studies/hubspot)
+- [See how doxy.me turned realtime from a liability into a strategic asset](https://ably.com/case-studies/doxyme)
+</Aside>
+