Microsoft Bot Framework and Azure AI Bot Service provide tools to build, test, deploy, and manage intelligent bots. The modular SDK includes tools and templates for bots that can use speech, understand natural language, and handle questions and answers. Development tools work with a Connector service for exchanging messages and events, alongside Azure deployment and channel configuration. Client libraries are available for C#, JavaScript, Python, and Java. Bots can connect to channels such as Microsoft Teams, Facebook, and Slack through Azure AI Bot Service channels or channel adapters; the listed capabilities also include a visual flow builder, knowledge-base answers, and human handoff. Hosting can be on a developer’s own servers, in Azure, or in another data center, provided the bot exposes a publicly accessible HTTPS endpoint. Bot Service channels require HTTPS and TLS 1.2, and the SDK automates basic bot-to-channel authentication. The Free plan is free and includes unlimited standard-channel messages and 10,000 premium-channel messages per month. Microsoft says the SDK is no longer updated or maintained and recommends the Microsoft 365 Agents SDK for new agent development. It also says support tickets for the Bot Framework SDK will no longer be serviced as of December 31, 2025.
Who it is for
Microsoft Bot Framework suits developers building bots across channels such as Teams, Facebook, and Slack, particularly those who want client libraries in C#, JavaScript, Python, or Java. Its listed hosting options suit teams able to expose a publicly accessible HTTPS endpoint and choose their own server or cloud environment.
What is good
- Includes tools and templates for speech, natural language, and Q&A bots.
- Provides client libraries for C#, JavaScript, Python, and Java.
- Connects bots to Teams, Facebook, Slack, and other channels.
- Allows hosting on own servers, Azure, or another data center.
- Free plan includes unlimited standard-channel messages.
- Supports identity providers including Microsoft Entra ID and GitHub.
What to know first
- Microsoft says the SDK is no longer updated or maintained.
- Microsoft recommends a different SDK for new agent development.
- Free plan limits premium-channel messages to 10,000 per month.
- Channel adapters may be needed for some channels or features.
Verdict
The Bot Framework may suit developers maintaining bots that need its SDK, channel connections, and hosting flexibility. For new agent development, Microsoft recommends the Microsoft 365 Agents SDK; teams relying on support tickets should also account for the stated end of Bot Framework SDK ticket service.
Get started with Microsoft Bot Framework
- Visit the Bot Framework website.
- Choose the Free plan or S1 plan.
- Build with the SDK tools and a client library for C#, JavaScript, Python, or Java.
- Configure deployment and channels through Azure AI Bot Service, or use channel adapters as needed.
- Host the bot on your own servers, in Azure, or in another data center with a publicly accessible HTTPS endpoint.
What the free plan stops at
The Free plan includes 10,000 premium-channel messages per month, while standard-channel messages are unlimited. Channel adapters may be needed when Azure AI Bot Service does not provide a desired channel or the required channel features.
Questions about Microsoft Bot Framework
Is Microsoft Bot Framework free?
A Free plan is listed at no cost. It includes unlimited standard-channel messages and 10,000 premium-channel messages per month.
Which programming languages have client libraries?
The Bot Framework provides client libraries for C#, JavaScript, Python, and Java.
Which channels can bots connect to?
Bots can connect to channels such as Microsoft Teams, Facebook, and Slack using Azure AI Bot Service channels or channel adapters.
Where can a bot be hosted?
It can be hosted on the developer’s own servers, in Azure, or in another data center, as long as it exposes a publicly accessible HTTPS endpoint.
Is the Bot Framework SDK maintained?
Microsoft says the SDK is no longer updated or maintained and recommends the Microsoft 365 Agents SDK for new agent development. Microsoft also says Bot Framework SDK support tickets will no longer be serviced as of December 31, 2025.
Microsoft Bot Framework plans and pricing
All plansCompared on chatbot builders
- Free plan
- Yes
- Deployment channels
- multichannel
- Visual flow builder
- Yes
- Knowledge-base answers
- Yes
- Human handoff
- Yes
