Ask the operator to open a URL

Connected Accounts, device login, any hop that belongs in a browser: your action returns a Started ticket with a URL. The harness should show that URL, then wait until your callback says the grant finished. Mark the action. Register a waiter. Tokens never go through the chat.

Mark the URL

Restier / controllers
ModelBuilder

using Microsoft.OData.Mcp.Core.Vocabularies;

[BoundOperation(OperationType = OperationType.Action)]
[McpTask]
[McpElicitUrl("connectUri")]
public AuthorizationTicket Authorize(IntegrationConnection connection)
{
    return ticket;
}

builder.EntityType<IntegrationConnection>()
    .Action("Authorize")
    .HasMcpTask()
    .HasMcpElicitUrl("connectUri")
    .Returns<AuthorizationTicket>();

Keep returning one JSON ticket, for example:

{
  "status": "Started",
  "connectUri": "https://login.example.com/connect/...",
  "expiresIn": 600,
  "message": "Open the URL to finish authorization."
}

If you omit [McpElicitUrl], the host looks for connectUri, url, authorizationUrl, or verificationUri on that JSON. Names that look like secrets (token, password, code) are ignored on purpose. Pair it with [McpTask] / HasMcpTask() so the harness waits while the operator is in the browser.

Wait until your callback fires

builder.Services.AddODataMcp(options => { }, mcp =>
{
    mcp.WaitForAnnotatedAction<AuthorizeWaiter>();
});

public sealed class AuthorizeWaiter : IMcpAnnotatedActionWaiter
{
    private readonly ConnectionSessions _sessions;

    public AuthorizeWaiter(ConnectionSessions sessions) => _sessions = sessions;

    public async Task<CallToolResult?> WaitAsync(
        McpAnnotatedActionContext context,
        CancellationToken cancellationToken)
    {
        var json = await _sessions.WaitAsync(context.BindingKey, cancellationToken);
        return new CallToolResult
        {
            Content = [new TextContentBlock { Text = json }]
        };
    }
}

context has the action name, the entity key, and the Started JSON. Return null to keep that Started payload. Without a waiter, the harness still shows the URL, then the call ends. The operator finishing in the browser never comes back on MCP. If the harness cannot show a URL, they get the Started ticket and the human says when they are done.

If you also enabled Tasks

The same elicitation is nested on the task. The operator accepts or declines; accept runs the waiter; decline skips it. Pair WithTasks and WaitForAnnotatedAction in the same AddODataMcp callback.

Getting Started

API Reference

Ask the operator to open a URL

Mark the URL

Wait until your callback fires

​Mark the URL

​Wait until your callback fires

Mark the URL

Wait until your callback fires