# Plain vs Siena AI

> Plain: AI-powered support platform for B2B teams, unifying Slack, email and chat in one workspace
> Siena AI: AI customer service agents that resolve e-commerce support tickets in your brand voice

- Plain profile: https://finderatlas.com/tools/plain
- Siena AI profile: https://finderatlas.com/tools/siena-ai
- Comparison page: https://finderatlas.com/compare/plain-vs-siena-ai
- Last reviewed: November 2026

## Verdict

Plain is listed under Help Desk Software and Siena AI under AI Customer Support. Neither has a free plan. Only Plain offers an API.

### Choose Plain if

- You want a tool built for Teams that support business customers through shared Slack or Teams channels and want AI triage, routing and an API-first setup.
- Built around B2B support, with Slack, Teams and Discord channels alongside email and chat.
- Ari and Sidekick AI agents are included from the entry plan.

### Choose Siena AI if

- You want a tool built for brands with high ticket volume on Shopify and a helpdesk such as Gorgias or Zendesk that want to automate order, return and subscription requests.
- Wide set of named integrations across helpdesks, subscriptions, returns, shipping and reviews.
- Covers support, shopping, social, reviews and QA agents on one platform.

## Pricing

| | Plain | Siena AI |
| --- | --- | --- |
| Pricing model | Free trial | Paid |
| Free plan or trial | No | No |
| Starting price | $45 | $750 |

## Features

| Feature | Plain | Siena AI |
| --- | --- | --- |
| Multichannel Inbox | Yes | Not listed |
| Ari AI Agent | Yes | Not listed |
| Sidekick | Yes | Not listed |
| Workflows | Yes | Not listed |
| Insights | Yes | Not listed |
| Bring Your Own Agents | Yes | Not listed |
| API | Yes | Not listed |
| Help Center and Knowledge Base | Yes | Not listed |
| Customer Service Agent | Not listed | Yes |
| Post-Purchase Workflows | Not listed | Yes |
| Subscription Management | Not listed | Yes |
| Shopping Agent | Not listed | Yes |
| Social Agent | Not listed | Yes |
| Reviews Agent | Not listed | Yes |
| QA Agent and Topics Explorer | Not listed | Yes |
| Agent Assist | Not listed | Yes |
| Guardrails and Controls | Not listed | Yes |

## Platforms

| Platform | Plain | Siena AI |
| --- | --- | --- |
| Web | Yes | Yes |
| Windows | No | No |
| macOS | No | No |
| iOS | No | No |
| Android | No | No |
| API | Yes | No |
| Browser Extension | No | No |

## Plain strengths

- Built around B2B support, with Slack, Teams and Discord channels alongside email and chat.
- Ari and Sidekick AI agents are included from the entry plan.
- API-first design allows custom workflows and embedding.
- 7-day trial without a credit card, plus a 50% startup discount.
- Enterprise options include SSO, SCIM and HIPAA on the Frontier plan.

## Plain limitations

- No permanently free plan; paid plans start at $45 per user per month.
- AI usage is metered in credits (1,000 per month on Foundation), which makes costs harder to predict.
- Microsoft Teams and CRM integrations require the $99 Horizon plan.
- No iOS or Android app was found.

## Siena AI strengths

- Wide set of named integrations across helpdesks, subscriptions, returns, shipping and reviews.
- Covers support, shopping, social, reviews and QA agents on one platform.
- Transparent base pricing: $750/month plus $0.90 per automated ticket.
- Enterprise controls including SOC 2 Type II, SAML SSO and audit logs.
- Funded company with a $17M Series A and a customer list of recognizable DTC brands.

## Siena AI limitations

- $750/month minimum platform fee is high for small stores.
- No free tier or self-serve trial listed.
- Implementation and support pricing is not published.
- Focused on e-commerce brands, so less suited to B2B or non-commerce support.

## FAQ

**Is Plain better than Siena AI?**

It depends on your workflow. Plain is built for Teams that support business customers through shared Slack or Teams channels and want AI triage, routing and an API-first setup. Siena AI is built for brands with high ticket volume on Shopify and a helpdesk such as Gorgias or Zendesk that want to automate order, return and subscription requests.

**What are the key feature differences between Plain and Siena AI?**

Plain: AI-powered support platform for B2B teams, unifying Slack, email and chat in one workspace. Siena AI: AI customer service agents that resolve e-commerce support tickets in your brand voice.

**Does Plain or Siena AI have a free plan?**

Neither has a free plan. Both Plain and Siena AI are paid products.

**Which is cheaper, Plain or Siena AI?**

Plain starts at $45 and Siena AI starts at $750. See the pricing table above for what each tier includes.