VIDEO TUTORIAL: Add Custom APIs and MCP Servers to Declarative Agents
Short video walkthrough on how to plug custom HTTP APIs and MCP servers into Declarative Agents.
Heads up: This is a video-first tutorial. The post just sets the context: everything interesting happens in the recording below.
If you’ve tried Agent builder inside Microsoft 365 Copilot, you know how fast it is to spin up a declarative agent: define its purpose, add a few knowledge sources, publish, done.
But there’s a catch today:
- You can’t directly add custom HTTP APIs from the Agent builder UI
- You can’t directly add MCP servers either
So many people assume: “I guess declarative agents can’t call my backend or MCP tools yet.”
This video shows how to get around that assumption and wire custom APIs and MCP servers into a declarative agent anyway, in a way that is:
- Quick to set up
- Repeatable
- Demo‑friendly (we do it live, end-to-end)
Watch the tutorial
Video: Add custom APIs and MCP servers to declarative agents in Microsoft 365 Copilot
Tip: Watch in fullscreen and pause as you follow along in your own tenant—the video is paced so we can build everything together.
What you’ll see in the video
In the recording we walk through, step by step:
- Creating a plain declarative agent to be used in Microsoft 365 Copilot (PAYG with Copilot Credits is possible)
- Introducing a custom HTTP API so the declarative agent can talk to your own backend logic
- Testing the whole flow live so you can see:
- The agent calling your custom API
- How the end‑user experience looks inside Microsoft 365 Copilot
No slides, no theory-only content but instead a practical, live build you can replicate.
Who is this for?
This video is useful if you:
- Already build agents with Agent builder and feel limited by the current UI
- Want your declarative agents to call your own APIs or MCP servers
- Prefer to watch a complete setup rather than following our engineering docs
If that’s you, hit play and build along. Already watched? Tell me if you liked or not in the comments: it’s my first video and I’m not sure if you prefer more blog content or videos.