# Tencent RTC RTC Engine — Flutter > RTC Engine documentation for Flutter platform. ## Core SDK ### Get Started - [Activate Service](https://pre.trtc.io/document/73281.md): Tencent RTC-Engine is a real-time communication SDK offering audio and video call capabilities, cloud recording, mixed-stream transcoding, and live streaming relay. This guide helps users activate the trial service, create applications, run demos, purchase official subscriptions, renew or upgrade editions, and enable automatic renewal. Follow step-by-step instructions to quickly start using Tencent RTC-Engine for your audio and video communication needs. - [Run the Demo](https://pre.trtc.io/document/39243.md): The TRTC Flutter SDK Quickstart Guide provides step-by-step instructions to create an application, obtain necessary credentials, download sample code, configure the project, and compile and run the demo on Android, iOS, Windows, and macOS. It addresses environment requirements and common troubleshooting FAQs to help developers quickly integrate and test Tencent RTC's real-time communication capabilities using Flutter. - [Integration](https://pre.trtc.io/document/64203.md): Tencent RTC Flutter SDK is a real-time communication SDK designed for Flutter developers to implement audio and video calls on Android and iOS platforms. This quickstart guide covers environment setup, SDK import, project configuration, TRTC instance creation, room entry, and enabling camera and microphone functionalities to help developers quickly integrate basic audio and video call features. ### Build with AI - [Overview](https://pre.trtc.io/document/77713.md): Tencent RTC Overview provides a comprehensive guide to integrating AI tools with Chat, Live, Call, Conference, and RTC Engine. It introduces the Model Context Protocol (MCP) server for automated credential generation and supported tools, Agent Skills for natural language task workflows, and LLMs.txt Markdown indexes for documentation. This overview helps developers quickly start, implement scenarios, and access official knowledge base resources with ease. - [Configure MCP Server](https://pre.trtc.io/document/78382.md): The MCP Server configuration guide provides step-by-step instructions to set up the AI-powered MCP solution for TRTC Knowledge Query and UI-Integrated Feature Implementation. This guide helps developers configure MCP in various AI development environments such as Cursor, Codex, Claude, and others by setting necessary environment variables and verifying the setup. It supports multiple platforms including Web, Android, iOS, and Flutter, enabling efficient integration of real-time audio/video features and API queries. - [Install Skills](https://pre.trtc.io/document/78383.md): TRTC Agent Skills is an AI-powered integration assistant SDK designed to simplify the integration of Tencent RTC products. It supports multiple IDEs and guides developers through installation, configuration, and feature integration with natural language commands. This guide covers installation steps, session reload instructions, and how to get started using the Skill for running demos, adding features, troubleshooting, and querying documentation. ### Basic Features - [UserSig Authentication](https://pre.trtc.io/document/35166.md): This guide explains how to calculate UserSig, a security signature for Tencent-RTC services, during the debugging phase. It covers obtaining SDKAppID and SDKSecretKey from the Tencent-RTC console and generating UserSig using client sample code on multiple platforms including Android, iOS, Web, Windows, Flutter, and Mac. The steps ensure secure authentication for developers testing Tencent-RTC SDKs before official deployment. - [Network Quality Probing](https://pre.trtc.io/document/58958.md): The TRTC Flutter SDK offers a callback event onNetworkQuality to monitor the current network quality during audio and video calls. This guide explains how to interpret local and remote network quality levels reported every two seconds and implement corresponding UI prompts to ensure smooth communication experiences. - [Video Quality & Encoding Profiles](https://pre.trtc.io/document/58960.md): Tencent RTC's TRTCCloud SDK for Flutter enables developers to configure video quality through parameters like TRTCAppScene, video encoder settings, and network QoS policies. It supports multiple platforms including iOS, Android, macOS, Windows, Web, Electron, and Flutter. The SDK offers various room scenarios such as video calls, interactive live streaming, audio calls, and voice chat rooms, each with tailored capabilities like user limits and latency optimizations. Recommended video encoding settings cover resolution, frame rate, and bitrate to optimize streaming quality across different use cases. - [Video Rotation](https://pre.trtc.io/document/58961.md): Tencent Real-Time Communication (TRTC) Flutter SDK is a real-time audio and video communication platform supporting multiple platforms including iOS, Android, macOS, Windows, Electron, and Flutter. It addresses the need for both portrait and landscape screen orientation modes, enabling applications like WeChat-style video calls and multi-person audio-video rooms. The SDK provides configuration methods for UI orientation, video encoder parameters, and tailored control over rotation direction and fill patterns to ensure consistent user experience across devices. - [Screen Sharing](https://pre.trtc.io/document/39859.md): Tencent Cloud TRTC Flutter SDK enables screen sharing capabilities on Android and iOS platforms. This guide helps developers start screen sharing by calling the startScreenCapture API and configuring encoding parameters such as resolution, frame rate, and bitrate. It covers Android-specific requirements like floating window display to avoid app termination and explains iOS in-app and cross-app sharing solutions for different privacy needs. ### Advanced Features - [Basic Beauty Effects](https://pre.trtc.io/document/69082.md): Tencent Special Effect Beauty SDK for Flutter provides a comprehensive guide to integrate beauty effects into Android and iOS applications. This quickstart covers seamless migration of special effect resources, adding dependencies, configuring obfuscation rules, and associating beauty effects with Tencent Real-Time Communication (TRTC). It is designed for developers aiming to enhance their Flutter apps with advanced beauty effect capabilities. - [Watermark](https://pre.trtc.io/document/64202.md): The Flutter TRTC SDK quickstart guide demonstrates how to add, display, and remove a watermark on a video stream. It provides step-by-step instructions for enabling the camera, setting a PNG watermark image with specified coordinates and size, pulling the watermarked remote video stream, and removing the watermark by setting a null value. This guide is intended for developers integrating watermarking features into their Flutter applications using Tencent RTC. - [Custom Messages / SEI Messages](https://pre.trtc.io/document/47866.md): The TRTC SDK is a real-time communication SDK that enables anchors in a video room to send custom messages to other participants. This guide covers the steps to send custom messages on supported platforms including iOS, Android, Web, macOS, Windows, Electron, and Flutter. It explains how to use the sendCustomCmdMsg API with required parameters such as message ID, data content, and reliability options to ensure ordered and reliable message delivery. ### Client APIs - [Overview](https://pre.trtc.io/document/39169.md): TRTCCloud SDK offers a detailed API reference for real-time audio and video communication, enabling developers to manage rooms, control media streams, handle device and audio effects, and implement screen sharing. This documentation supports developers integrating TRTCCloud functionalities across platforms, providing essential methods for singleton management, event handling, and media control to build interactive communication applications. - [Error Codes](https://pre.trtc.io/document/39168.md): Tencent RTC error codes document the common error values and their descriptions for troubleshooting audio and video communication problems. It covers errors related to room entry and exit, device failures such as camera and microphone issues, screen sharing errors, and more. This guide helps developers quickly identify error causes and apply appropriate fixes using callback notifications from the Tencent RTC SDK. ### FAQ - [FAQs for Beginners](https://pre.trtc.io/document/38104.md): Tencent Real-Time Communication (TRTC) FAQs provide essential information for beginners about the TRTC SDK, including UserSig security, supported platforms, room capacity, live streaming roles, screen sharing, and troubleshooting common issues. This guide helps developers understand how to use TRTC features effectively and resolve typical problems encountered during integration and usage. - [Billing](https://pre.trtc.io/document/42298.md): Tencent Real-Time Communication (TRTC) Billing FAQ provides detailed answers on billing methods, discounts for high-demand customers, usage tracking, and cost estimation. It explains how TRTC services are billed, how to view bills and usage details, and clarifies billing for audio and video durations. The FAQ also covers how free minutes and Monthly Active Users (MAU) are calculated across multiple subscription packages with the same SDKAppID, helping users manage and estimate their TRTC service expenses effectively. - [Features](https://pre.trtc.io/document/36057.md): Tencent Real-Time Communication (TRTC) SDK offers a comprehensive platform for developing interactive audio and video communication applications. Designed for developers needing group audio/video calls and low-latency live streaming, TRTC supports diverse scenarios such as video calls, live streaming, and voice chat rooms. Key features include flexible role management, manual stream subscription, support for large concurrent audiences, and multi-platform demos for rapid deployment. - [Firewall Restrictions](https://pre.trtc.io/document/35164.md): Tencent TRTC SDK firewall restriction FAQ provides detailed guidance on the ports and domain names to add to firewall allowlists for native SDK and WebRTC clients. It also explains how to configure proxies using Nginx and Coturn to enable client access to the TRTC SDK from private networks, ensuring smooth connectivity and compliance with network security requirements. - [How to Downsize Installation Package](https://pre.trtc.io/document/35165.md): This FAQ document addresses how to reduce the installation package size after integrating the TRTC SDK for iOS and Android platforms. It explains the file size increments caused by the SDK and provides detailed methods such as packaging only specific architectures for iOS, enabling Bitcode, and selectively packaging or downloading .so files for Android. These solutions help developers optimize app size while maintaining TRTC SDK functionalities. - [TRTCCalling for Web](https://pre.trtc.io/document/43096.md): TRTCCalling for Web is a real-time communication SDK based on TRTC and TIM that enables one-to-one and group audio/video calls. This FAQ page helps developers and users resolve common issues such as browser compatibility, network quality testing, device permission errors, and integration challenges. It provides detailed explanations and solutions for errors encountered during audio/video calls and SDK operations to ensure smooth communication experiences. - [Audio and Video Quality](https://pre.trtc.io/document/43094.md): Tencent Real-Time Communication (TRTC) SDK offers comprehensive troubleshooting guidance for audio and video quality issues. This FAQ helps developers and users resolve common problems such as black bars in video images, video stutter, low-quality or blurry videos, audio volume and echo issues, and device status errors. It also explains how to monitor network status and adjust video orientation and mirroring settings to optimize call and streaming experiences. - [Others](https://pre.trtc.io/document/36058.md): Tencent Real-Time Communication (TRTC) FAQ provides solutions to common issues and questions related to live streaming, interactive live streaming, relayed live streaming, and TRTC usage. It covers topics such as differences between streaming types, user ID conflicts, playback stuttering, room entry errors, log viewing, error codes, and cross-room calls. This guide helps developers and users troubleshoot and optimize their TRTC and live streaming experience across multiple platforms including iOS, Android, Windows, and Web. - [Flutter FAQs](https://pre.trtc.io/document/39242.md): Tencent RTC Flutter SDK FAQ provides solutions to common issues encountered during integration and usage on mobile platforms. It addresses problems such as image display between devices, firewall restrictions on UDP, iOS build and runtime errors including symbol not found and app crashes, Android build failures, CocoaPods errors, and dependency conflicts. This guide helps developers resolve platform-specific challenges and optimize their TRTC Flutter app experience. - [Upgrade Guide](https://pre.trtc.io/document/66724.md): Tencent RTC SDK Upgrade Guide provides detailed steps for Flutter developers to transition from tencent_trtc_cloud to the new tencent_rtc_sdk. It covers replacing import packages, updating enumerated values to Dart enums, modifying callback usage, and invoking new methods. This guide helps ensure a smooth upgrade process by outlining precautions and solutions for common issues.