# AI support chatbot pricing example

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 |
| 300 token events per LLM response | |
| 75 appends per second from agent | |
| 3 minute average chat duration | |
| 1 million chats | |

### Cost summary

The high level cost breakdown for this scenario is given in the table below. Messages are billed for both inbound (published to Ably) and outbound (delivered to subscribers). Enabling the "Message updates, deletes and appends" [channel rule](https://ably.com/docs/ai-transport/token-streaming/message-per-response.md#enable) will automatically enable message persistence.

| Item | Calculation | Cost |
|------|-------------|------|
| Messages | 1212M × $2.50/M | $3030 |
| Connection minutes | 6M × $1.00/M | $6 |
| Channel minutes | 3M × $1.00/M | $3 |
| Package fee |  | [See plans](https://ably.com/pricing) |
| **Total** |  | **~$3039/M chats** |

### Message usage breakdown

Several factors influence the total message usage. The message-per-response pattern includes [automatic rollup of append events](https://ably.com/docs/ai-transport/token-streaming/token-rate-limits.md#per-response) to reduce consumption costs and avoid rate limits.

- Agent stream time: 300 token events ÷ 75 appends per second = 4 seconds of streaming per response
- Messages published after rollup: 4 seconds x 25 messages/s = **100 messages per response**

| Type | Calculation | Inbound | Outbound | Total messages | Cost |
|------|-------------|---------|----------|----------------|------|
| User prompts | 1M chats × 4 prompts | 4M | 4M | 8M | $20 |
| Agent responses | 1M chats x 4 responses x 100 messages per response | 400M | 400M | 800M | $2000 |
| Persisted messages | Every inbound message is persisted | 404M | 0 | 404M | $1010 |
| **Total** | | **808M** | **404M** | **1212M** | **$3030** |

<Aside data-type='further-reading'>
Useful links for exploring this topic in more detail.
- [Talk with sales](https://ably.com/contact) to get a personalized 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>