Agash.YTLiveChat.DependencyInjection 4.2.0-dev3

YTLiveChat

Unofficial .NET library for reading YouTube live chat via InnerTube (the same web-facing surface YouTube uses), without Data API quotas or OAuth setup.

Targets

• net10.0
• net9.0
• netstandard2.1
• netstandard2.0

Install

Core package:

dotnet add package Agash.YTLiveChat

With DI helpers:

dotnet add package Agash.YTLiveChat.DependencyInjection

What You Get

Chat messages

• Chat messages (ChatReceived) — text, emoji, images
• Super Chats / Super Stickers with parsed amount + currency
• Membership events — new join, milestone, gift purchase, gift redemption, tier upgrade (MembershipDetails.EventType)
• Ticker support (addLiveChatTickerItemAction) — paid messages, membership items, gift purchase announcements; ticker items include author channel ID, author thumbnail, and Author.ChannelHandle (the @handle) when available
• Viewer leaderboard rank extraction via ChatItem.ViewerLeaderboardRank (YouTube points crown tags like #1)

Moderation & lifecycle

• Message deleted (ChatItemDeleted) — single item removed
• Author banned/cleared (ChatItemsDeletedByAuthor) — all messages from a channel removed
• Message replaced (ChatItemReplaced) — slow-mode or placeholder resolution

Polls

• PollUpdated — fires when a new poll opens (Poll.IsNew == true) and on every vote-count update (IsNew == false); carries Question (MessagePart[]?), structured Choices (each with Text: MessagePart[] and VoteRatio), CreatorHandle, and TotalVotes
• PollClosed — fires when the poll panel is dismissed; use PollId to correlate with the preceding PollUpdated events
• After PollClosed, EngagementMessageReceived fires with MessageType == PollResult carrying the final summary in Message (MessagePart[], not required for poll lifecycle tracking)

Banners

• BannerAdded — fires with a BannerItem subclass; pattern-match to distinguish:
  • PinnedMessageBannerItem — pinned chat message; carries Author, Message (MessagePart[]), PinnedBy, Timestamp, and role flags (IsOwner, IsModerator, IsVerified)
  • CrossChannelRedirectBannerItem — cross-channel banner; check RedirectType (Redirect = owner redirecting viewers to another stream, Raid = another channel's viewers joining here); carries RedirectChannelHandle (the @handle), RedirectVideoId (non-null only for Redirect), and BannerMessage (MessagePart[])
  • ChatSummaryBannerItem — AI-generated chat summary (experimental YouTube feature); carries Summary (MessagePart[]) with bold title, deemphasized disclaimer, and body text runs, plus SummaryId
• BannerRemoved — banner dismissed; TargetActionId matches the preceding BannerAdded's ActionId

System / engagement messages

• EngagementMessageReceived — YouTube-generated notices in the chat feed; Message is MessagePart[]:
  • CommunityGuidelines — welcome/guidelines reminder at stream start
  • SubscribersOnly — subscribers-only mode notice
  • PollResult — formatted poll result summary (see Polls above)

Raw access

• RawActionReceived — every InnerTube action including unsupported ones
• Async streaming APIs (StreamChatItemsAsync, StreamRawActionsAsync)

Important Caveats

• This is an unofficial parser over YouTube’s internal schema. Payloads can change at any time.
• This library reads chat only (no sending messages).
• Respect request frequency to avoid rate limits or temporary blocks.

Beta API Notice

Continuous livestream monitor mode is currently BETA/UNSUPPORTED and can change or break at any time:

• YTLiveChatOptions.EnableContinuousLivestreamMonitor
• YTLiveChatOptions.LiveCheckFrequency
• IYTLiveChat.LivestreamStarted
• IYTLiveChat.LivestreamEnded
• IYTLiveChat.LivestreamInaccessible

These members intentionally emit compiler warnings via [Obsolete] to signal unstable API status.

Monitor note: channel/watch page resolution is fetched via stateless (no-cookie) requests inside the library to reduce consent-interstitial loops during long-running monitor sessions.

Quick Start (DI)

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using YTLiveChat.Contracts;
using YTLiveChat.Contracts.Services;
using YTLiveChat.DependencyInjection;

HostApplicationBuilder builder = Host.CreateApplicationBuilder(args);
builder.Services.AddYTLiveChat(builder.Configuration);

builder.Services.Configure<YTLiveChatOptions>(options =>
{
    options.RequestFrequency = 1000;
    options.DebugLogReceivedJsonItems = true;
    options.DebugLogFilePath = "logs/ytlivechat_debug.json";
});

builder.Services.AddHostedService<ChatWorker>();
await builder.Build().RunAsync();

Worker example:

using YTLiveChat.Contracts.Models;
using YTLiveChat.Contracts.Services;

public sealed class ChatWorker(IYTLiveChat chat) : IHostedService
{
    public Task StartAsync(CancellationToken ct)
    {
        chat.InitialPageLoaded += (_, e) => Console.WriteLine($"Loaded: {e.LiveId}");
        chat.ChatReceived += (_, e) => HandleChat(e.ChatItem);
        chat.RawActionReceived += (_, e) =>
        {
            if (e.ParsedChatItem is null)
            {
                // Unsupported action still available here
                Console.WriteLine("RAW action received.");
            }
        };
        chat.ChatStopped += (_, e) => Console.WriteLine($"Stopped: {e.Reason}");
        chat.ErrorOccurred += (_, e) => Console.WriteLine($"Error: {e.GetException().Message}");

        chat.Start(handle: "@channelHandle");
        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken ct)
    {
        chat.Stop();
        return Task.CompletedTask;
    }

    private static void HandleChat(ChatItem item)
    {
        // inspect item.Superchat, item.MembershipDetails, item.ViewerLeaderboardRank, item.IsTicker
        // for ticker events: item.Author.ChannelId, item.Author.Thumbnail, item.Author.ChannelHandle
    }
}

Async Streaming APIs

await foreach (ChatItem item in chat.StreamChatItemsAsync(handle: "@channel", cancellationToken: ct))
{
    Console.WriteLine($"{item.Author.Name}: {string.Join("", item.Message.Select(ToText))}");
}

await foreach (RawActionReceivedEventArgs raw in chat.StreamRawActionsAsync(liveId: "videoId", cancellationToken: ct))
{
    if (raw.ParsedChatItem is null)
    {
        Console.WriteLine(raw.RawAction.ToString());
    }
}

static string ToText(MessagePart part) => part switch
{
    TextPart t => t.Text,
    EmojiPart e => e.EmojiText ?? e.Alt ?? "",
    _ => ""
};

TextPart carries Bold, Italics, and IsDeemphasized flags so consumers can render formatting without re-parsing. All structured message fields across the library (ChatItem.Message, EngagementItem.Message, PollChoice.Text, PollItem.Question, banner Summary/BannerMessage/Message) are MessagePart[] — concatenate TextPart.Text values for plain text, or pattern-match on the flags for rich rendering.

Raw JSON Capture for Schema Analysis

Enable:

options.DebugLogReceivedJsonItems = true;
options.DebugLogFilePath = "logs/ytlivechat_debug.json";

The file is written as a valid JSON array, so it is directly parseable by tools/scripts.

Example App

YTLiveChat.Example includes:

• UTF-8 console setup for multilingual output
• colorized one-line TUI rendering
• rank/ticker/membership/superchat tagging
• unsupported raw action hints
• optional raw JSON capture prompt
• optional continuous monitor mode prompt (beta)

Current Schema Coverage Gaps

• Creator goals are not mapped yet (awaiting enough stable raw samples).

Contributing

Bug reports and raw payload samples are highly valuable.
If you add parser support for new payloads, include:

• response model updates in YTLiveChat/Models/Response/LiveChatResponse.cs
• parser updates in YTLiveChat/Helpers/Parser.cs
• tests + fixtures in YTLiveChat.Tests

Acknowledgements

• WolfwithSword — testing and feedback

License

MIT. See LICENSE.txt.