Build Graph-backed plugins

Overview

A Graph plugin is application code using a protected connection; FabrCore does not automatically ship every mail/calendar/SharePoint operation. GetHttpClientAsync keeps token acquisition out of the model interface. Separate read, draft and send/write operations.

Resolve the client inside trusted code

GetHttpClientAsync obtains a client through the configured connection/resource. The model supplies a business request such as a date range, while the plugin supplies the authorized connection context. This keeps token acquisition and audience selection out of the model's argument list. Validate the actual Graph operation and handle response errors in the plugin.

Separate reads from writes

Reading a calendar, drafting a change and sending an invitation are different business operations. Give them separate tool contracts and authorization/review behavior. Return only the fields needed for the assistant's task, and do not include tokens or full provider error dumps in model context. The broker does not supply every possible Graph business tool for you.

Call Graph from a narrow plugin

1. Resolve the graph resource with Connections.GetHttpClientAsync in trusted agent/plugin code. Start with a permitted profile or calendar read.
2. Add bounded calendar availability, mail-draft or SharePoint/OneDrive document retrieval functions with operation-specific permissions. Use raw tokens only for trusted SDKs that require them.
3. For writes, validate owner, inputs and explicit application approval, then verify the external result. Feed retrieved policy files into the established knowledge ingestion path.

using var graph = await Connections.GetHttpClientAsync("mail", "graph", ct);
var messages = await graph.GetStringAsync(
    "users/" + Uri.EscapeDataString(mailbox) + "/messages?$top=10", ct);

// Only when a trusted SDK requires the raw token:
var token = await Connections.GetAccessTokenAsync("mail", "graph", ct);
await trustedSdk.CallAsync(token.AccessToken, ct);

Go deeper

Explore the related documentation.

• FabrCore Microsoft Integrations
• FabrCore Connections
• FabrCore Microsoft 365 Copilot
• FabrCore A2A
• Agent SDK usage and MCP