animated_streaming_markdown 0.1.4

Flutter markdown streaming package for Android/iOS/macOS/Linux/Windows (web is not supported).

animated_streaming_markdown

This package is vibe-coded and currently under active construction.

API surface and behavior may change while streaming and rendering features are being stabilized.

Overview

animated_streaming_markdown is a Flutter FFI package for markdown streaming workflows. It exposes:

• append-friendly rope buffers (RopeString, NativeRopeBuffer)
• native tree-sitter markdown parsers (TreeSitterMarkdownParser)
• native incremental parser sessions (NativeIncrementalMarkdownParser)
• isolate-based parsing for UI pipelines (StreamingMarkdownParseWorker)
• a streaming-friendly Flutter renderer (StreamingMarkdownRenderView)

Platform Support

• Supported: Android, iOS, Linux, macOS, Windows
• Not supported: Web

Installation

Add dependency:

dependencies:
  animated_streaming_markdown: ^0.1.4

Then run:

flutter pub get

Quick Start

import 'package:animated_streaming_markdown/animated_streaming_markdown.dart';

Future<void> parseIncrementally() async {
  final worker = StreamingMarkdownParseWorker();
  await worker.start();

  await worker.request(
    op: 'set',
    text: '# Hello\n\n| A | B |\n| - | - |\n',
    includeNodes: true,
  );

  final result = await worker.request(
    op: 'append',
    text: '| 1 | 2 |\n',
    includeNodes: true,
  );

  // Use result.renderNodes in StreamingMarkdownRenderView.
  print(result.renderNodes.length);

  worker.dispose();
}

Flutter Rendering

StreamingMarkdownRenderView(
  nodes: renderNodes,
  tokenArrivalDelay: const Duration(milliseconds: 50),
  tokenFadeInDuration: const Duration(milliseconds: 300),
  enableTextSelection: true,
)

HTML block nodes are rendered with pure Flutter widgets (no embedded WebView), so the block naturally wraps its content height instead of using a fixed viewport.

Web is intentionally not a supported target for this package.

Public API Documentation

Public API docs are written as DartDoc comments directly in source files:

• lib/animated_streaming_markdown.dart (entrypoint and export guide)
• exported API classes in lib/src/*

Use IDE hover/completion docs or dart doc to generate HTML docs.

Example App

See example/ for a dual-pane chat demo (default theme vs custom theme) with shared question input and streaming markdown rendering.

Bundled Tree-sitter Dependencies

This package vendors only the required native sources under packages/:

• packages/tree-sitter (tree-sitter runtime)
• packages/tree-sitter-markdown (block + inline markdown grammars)

Both bundled upstream components are MIT-licensed. Current package (animated_streaming_markdown) remains Apache-2.0.

License

animated_streaming_markdown is licensed under Apache License 2.0. See LICENSE.

Third-party license details are listed in THIRD_PARTY_LICENSES.md.