agent_ui_kit_providers

Initial release.

Chat runtime

• ChatController — conversation state with streaming, cancellation, retry and tool-call bookkeeping. Supports a managed send() API backed by an AgentResponder, and a manual API (beginAssistantMessage / appendToken / upsertToolCall / completeMessage) for responses that interleave text with tool calls.
• ConversationController — manages which Conversation is loaded into a ChatController. New chat, switch threads, rename, pin, delete, and search across titles and message bodies, grouped by recency.
• Prompt editing — user messages can be rewritten in place via MessageEditor. ChatController.editMessage discards everything after the edited message and regenerates, since replies to the old wording no longer belong to the thread. Disable with allowEditing: false.
• Models — ChatMessage, ToolCall, Attachment, Citation, Conversation, with copyWith, value equality and status lifecycles.

Widgets

• ChatScreen — a complete prebuilt chat surface. Pass conversations: and it gains a ChatHistoryDrawer and a new-chat action.
• MessageList — auto-scroll that stops following when the user scrolls up, message grouping, and a jump-to-latest button.
• ChatBubble — markdown body, attachments, tool calls, citations, status and actions (copy, regenerate, feedback, edit), laid out in a single row beneath the bubble.
• CodeBlock — syntax highlighting, language label, copy button, and collapsing for very long snippets.
• ChatInputBar — a themeable composer; every control shares controlSize so it stays a true capsule with no dead space around its icons.
• MarkdownView — headings, lists, task lists, tables, blockquotes, code, links, images and autolinks, built to stream: it caches its previous parse and re-parses only the trailing block on each append, keeping rebuild cost linear across a streamed reply.
• SyntaxHighlighter — Dart, JavaScript, TypeScript, Python, JSON, SQL and shell, with a sensible fallback for unknown languages.
• More widgets — AgentAvatar, CitationChip, CitationList, AttachmentPreview, SuggestionChips, ChatEmptyState, MessageActionBar, ThinkingBubble, ChatHistoryDrawer.

Theming

• Design tokens — AgentColors, AgentTypography, AgentSpacing, AgentRadii, AgentMotion, composed into AgentThemeData with light(), dark(), glass() and fromTheme() variants.
• AnimatedAgentTheme — cross-fades between themes instead of snapping.
• Reduced-motion support throughout, via AgentTheme.motionOf. Semantics labels on every interactive element.

Providers (package:agent_ui_kit_providers/providers.dart)

• OpenRouterProvider and GeminiProvider — stream a real model's replies straight into a ChatController. asResponder() adapts either to the managed send() API; sendMessage() drives the manual API so tool calls the model requests surface as real ToolCalls. Neither executes tools itself — reporting a result back is the host app's job via controller.upsertToolCall.
• AgentProvider, ProviderEvent/TextDelta/ToolCallEvent, AgentProviderException — the shared base types behind both providers.
• This is the only part of the package with a dependency of its own (http), imported separately from lib/providers.dart. The UI layer (widgets, theme, markdown, controllers, models) has none.