Consent and GDPR

Your consent, live

This panel is wired straight to IBelemetryConsent - the same service the site's banner uses. Tick a feature to grant it, untick it to revoke it, or set a whole group at once. The decision is remembered in this browser, and the Live telemetry page shows what each grant lets through.

Features

The bit values are a wire contract shared by C# and the browser script: they cross the interop boundary as plain integers and are persisted in the browser, so they never change.

Groups

Banners rarely ask about twelve things. The groups are the usual three questions, as flags you can pass to SetAsync or combine with others:

Persistence is in no group: keeping unsent telemetry on the device is a question of its own. Grant it with GrantAsync(BelemetryFeatures.Persistence), or include it in what you pass to SetAsync.

How consent behaves

• Effective = configured AND granted. BelemetryOptions.Features (all by default) is what the app collects at all; IBelemetryConsent.Available reports it. A feature switched off by configuration is never collected, whatever is granted.
• Opt-in by default. Before the user decides, only Consent.Default is granted - None unless you set it, for example to Errors when error reporting is covered by legitimate interest, or to All for an app that needs no consent.
• Nothing undecided leaves the device. Records of features not yet granted are held in memory, up to Consent.PendingLimit (500). When the user decides, what they granted is sent and the rest is dropped.
• Revoking is immediate. Queued records of a revoked feature are discarded, and its device storage cleared: revoking Persistence clears the offline queue, Sessions the stored session, UserTracking the pseudo id and the user id.
• The choice is remembered (Consent.Persist, on by default) in localStorage under bit-belemetry-consent, and in a file in Hybrid apps. Recording the choice itself is strictly necessary, so it needs no consent of its own.
• Global Privacy Control is honored (Consent.HonorGlobalPrivacyControl, on by default): a browser sending GPC never gets the Analytics features, whatever is requested.
• No cookies. Belemetry sets none.
• Trace context still flows. Without Traces, activities are still created for propagation, so downstream services keep receiving the trace context - but nothing is recorded.

On WebAssembly and Hybrid consent is app-wide. On Blazor Server it belongs to the circuit's user - it lives in their browser - so IBelemetryConsent needs an interactive render mode there. The server pipeline is governed by Server.Features instead, since it serves every user at once.

builder.Services.AddBitBelemetryServices(options =>
{
    options.Features = BelemetryFeatures.All;              // what the app collects at all (default)

    options.Consent.Default = BelemetryFeatures.None;      // granted before a decision (default)
    options.Consent.Persist = true;                        // remember the choice (default)
    options.Consent.HonorGlobalPrivacyControl = true;      // GPC: never Analytics (default)
    options.Consent.PendingLimit = 500;                    // held until the decision (default)
});

A banner of your own

A banner needs three things from IBelemetryConsent: whether to show itself (IsDecided), a way to record the answer (SetAsync), and Changed to hide itself when the answer comes from elsewhere - a settings page, or another tab. It should wait for the first interactive render and RefreshAsync: the decision lives in the browser, and a prerendered banner would flash at every user who already chose.

@implements IDisposable
@inject IBelemetryConsent Consent

@if (_ready && Consent.IsDecided is false)
{
    <div class="consent-banner" role="dialog" aria-label="Telemetry consent">
        <p>We measure errors and usage to improve the app. Nothing is sent until you choose.</p>
        <button @onclick="() => Consent.SetAsync(BelemetryFeatures.All)">Accept all</button>
        <button @onclick="() => Consent.SetAsync(BelemetryFeatures.Diagnostics)">Diagnostics only</button>
        <button @onclick="() => Consent.SetAsync(BelemetryFeatures.None)">Reject</button>
    </div>
}

@code {
    private bool _ready;

    protected override void OnInitialized() => Consent.Changed += OnChanged;

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender is false) return;

        await Consent.RefreshAsync();
        _ready = true;
        StateHasChanged();
    }

    private void OnChanged(object? sender, EventArgs e) => _ = InvokeAsync(StateHasChanged);

    public void Dispose() => Consent.Changed -= OnChanged;
}

Outside .NET - on a static SSR page, or in plain JavaScript - the script has the same API:

API