Lowdefy

Highlights

• AI agents are now first-class in Lowdefy. New @lowdefy/ai-utils runtime, a config-driven AgentChat composite block built on Ant Design X, and four new provider connections (@lowdefy/connection-anthropic, @lowdefy/connection-openai, @lowdefy/connection-google, @lowdefy/connection-ai-gateway) let you wire a streaming, tool-using AI agent into any page from YAML. Agents support multi-turn tool calling, server-side hooks (instructions, onStart, onStepStart, onToolCallStart, onToolCallFinish, onStepFinish, onFinish) callable as Lowdefy endpoints, sub-agents exposed as tools, file attachments with S3 upload, reasoning/thinking display, source citation streaming, and context compaction via pruneMessages. Provider-agnostic by design through the Vercel AI SDK.

• AgentChat block: real-time streaming chat UI. Sequential message part rendering with configurable reasoning display, tool approval UI for endpoint and MCP tools marked confirm: true, file attachments (configurable accept types and max size, S3 upload integration), drawer display mode with a FloatButton trigger, source citation rendering, Mermaid diagrams, LaTeX, and syntax-highlighted code blocks (toggled via renderMermaid and codeHighlighter). Includes copy, feedback, regenerate, and delete message actions, plus suggestions and Sender.Header / Sender.Switch affordances. The new AgentConversations block provides a standalone conversations sidebar for independent placement.

• MCP integration: agents can use external tools via Model Context Protocol. New @lowdefy/connection-mcp connection type supports HTTP, SSE, and stdio transports. Agents can reference MCP connections via connectionId or inline config with build-time validation. Runtime MCP client creation does automatic tool discovery, merging, and cleanup, and tool approval support via confirm: true works for both endpoint tools and MCP sources.

• sharedState two-way binding: agents can read and write page state. The built-in update-page-state tool lets an agent write to the page state of the AgentChat block, so the agent can drive UI changes, fill forms, or read context the user has set elsewhere on the page.

• File system agent tools. Sandboxed listFiles, readFile, searchFiles, statFile, and resolvePath tools give agents scoped access to agent-specific file directories. copyAgentFileSystems emits an agentFileSystems.json manifest so the production server includes each agent's fileSystem.basePath in Next.js file tracing, so agents that read files work on Vercel and standalone (output: 'standalone') deployments without manual next.config.js configuration.

• blocks-aggrid: new cell.type: buttons renderer. Render a list of action buttons in a column with each button firing its own block-level event with the row data on the payload. Per-button properties mirror the antd Button block (title, icon, type, variant, color, size, shape, danger, ghost, hideTitle, disabled) plus row-data-path variants (titleField, iconField, disabledField, hiddenField) for per-row state. Use this for inline Edit/Delete/Approve actions without _if dispatching.

• blocks-aggrid: ag-grid upgraded to v32.3.9. Pulls in two majors of upstream fixes. The column header UX (hamburger column menu with filter popup) is preserved by default; opt into the new ag-grid v32 column menu via columnMenu: 'new' on the block. Cell focus is suppressed by default (suppressCellFocus: true) so the keyboard focus outline doesn't visually compete with built-in cell renderers; override with suppressCellFocus: false. Cell overflow is clipped so flex-rendered content stays inside its column.

• blocks-aggrid: tag cells render one tag per item for array-valued fields. The cell.type: tag renderer now accepts an array of strings in addition to a single string. Each item is rendered as its own styled tag and resolves its colour through the existing colorMap / colorFrom / default configuration. Empty arrays and arrays containing only null/empty entries render the em-dash placeholder. Single-string values are unchanged.

• blocks-aggrid: tag cells auto-colour by default. When a cell.type: tag column is used with no colorMap, colorFrom, or default, tag values are coloured from a stable hash so the same value always gets the same colour across rows, columns, and tables. The palette uses 12 antd named hues (red, volcano, orange, gold, yellow, lime, green, cyan, blue, geekblue, purple, magenta) and respects the active theme. Opt out with cell: { type: tag, default: default }.

• blocks-antd: PageHeaderMenu now has a default borderBottom, matching the existing default borders on PageSiderMenu and PageSidebarLayout, for visual consistency across the page menu blocks. The default can still be overridden via styles.header.

• blocks-markdown: antd declared as a peer dependency. MarkdownWithCode imports antd for theme-aware syntax highlighting but the package did not declare it in peerDependencies, causing module resolution failures when bundling apps that include @lowdefy/blocks-markdown without already pulling in antd. Now declares antd (>=6) as a peer dependency.

Changes

feat: Add AI agent support with multi-provider chat and tool use

Packages: @lowdefy/api, @lowdefy/build, @lowdefy/blocks-antd-x, @lowdefy/connection-ai-gateway, @lowdefy/connection-anthropic, @lowdefy/connection-google, @lowdefy/connection-mcp, @lowdefy/connection-openai, @lowdefy/server, @lowdefy/server-dev, @lowdefy/ai-utils

Agent Runtime (@lowdefy/ai-utils)

• handleAgentChat orchestrates the full agent lifecycle: tool merging, MCP client lifecycle, hook callbacks, and stream composition
• ToolLoopAgent handles multi-turn tool calling, streaming responses, and artifact cleaning
• createAgentUIStreamResponse converts agent output to a streaming HTTP response for the client
• buildAgentTools merges endpoint tools, MCP tools, and sub-agent tools into AI SDK tool objects
• buildPrepareStep enables dynamic tool phasing per step
• buildUpdatePageStateTool provides a built-in tool for the agent to write to page state via the AgentChat block
• File system agent tools: listFiles, readFile, searchFiles, statFile, resolvePath for sandboxed access to agent-scoped file directories
• pruneMessages for context compaction
• experimental_repairToolCall integration
• Sub-agent support — agents can be exposed as tools to other agents
• Reserved tool name collision detection (e.g. update-page-state)
• Server-side hooks (instructions, onStart, onStepStart, onToolCallStart, onToolCallFinish, onStepFinish, onFinish) callable as Lowdefy endpoints
• Provider-agnostic design using the Vercel AI SDK — supports reasoning/thinking display, providerOptions passthrough, and source citation streaming via sendSources
• Strip data: URL prefix from file attachments before AI SDK processing

AgentChat Block (@lowdefy/blocks-antd-x)

• New AgentChat composite block built on Ant Design X with real-time streaming display
• Sequential message part rendering with configurable reasoning/thinking display
• Tool approval UI for endpoint and MCP tools marked confirm: true
• File attachment support (configurable accept types and max size) with S3 upload integration
• Drawer display mode with a FloatButton trigger for embedding chat on any page
• Source citation rendering for source-url and source-document parts
• Mermaid diagrams, LaTeX, and syntax-highlighted code blocks (with copy + language label) — toggled via renderMermaid and codeHighlighter
• Copy, feedback, regenerate, and delete message actions
• Suggestions and Sender.Header / Sender.Switch UI affordances
• Configurable roles, avatars, and names per message role
• Event bridging for agent lifecycle events (onSuccess, onError, onFinish, onFeedback)
• sharedState two-way binding lets the agent read and write page state via the update-page-state tool

AgentConversations Block (@lowdefy/blocks-antd-x)

• New standalone conversations sidebar block, extracted from AgentChat for independent placement

Connection Plugins

• @lowdefy/connection-anthropic: Anthropic connection with AnthropicAgent resolver supporting Claude models
• @lowdefy/connection-openai: OpenAI connection with OpenAIAgent resolver supporting GPT models
• @lowdefy/connection-google: Google AI connection with GeminiAgent resolver, including thinkingConfig and safetySettings sugar props
• @lowdefy/connection-ai-gateway: Vercel AI Gateway connection with AIGatewayAgent resolver for routing to multiple providers through a single endpoint

MCP Integration (@lowdefy/connection-mcp, @lowdefy/ai-utils, @lowdefy/build)

• New Mcp connection type for HTTP, SSE, and stdio transport config
• Agents can reference MCP connections via connectionId or inline config with build-time validation
• Runtime MCP client creation with automatic tool discovery, merging, and cleanup
• Tool approval support via confirm: true on both endpoint tools and MCP sources

Build Pipeline (@lowdefy/build)

• buildAgents validates agent config (model, tools, sub-agents, MCP) and normalizes tool definitions
• writeAgents writes agent artifacts for server consumption
• Sub-agent circular reference detection
• Tool object format with confirm support
• MCP connectionId normalization (inline config vs reference)
• Lazy module variable resolution for agent properties referenced from modules
• Agent schema validation integrated into the build pipeline
• copyAgentFileSystems emits an agentFileSystems.json manifest so the production server can include each agent's fileSystem.basePath directory in Next.js file tracing — agents that read files now work on Vercel and standalone (output: 'standalone') deployments without manual next.config.js configuration

API (@lowdefy/api)

• Agent route handler (callAgent) for streaming agent responses
• Endpoint tool execution context with operator evaluation
• Sub-agent resolver methods for agents-as-tools
• MCP connectionId resolution at request time
• getAgentConfig and getAgentResolver helpers for runtime agent resolution

Servers (@lowdefy/server, @lowdefy/server-dev)

• Agent API route (/api/agent/[...path]) added to both production and development servers
• urlQuery validation
• 10 MB request body limit for file attachments
• Server-side hooks for agent lifecycle callbacks (instructions, onFinish)

feat(blocks-aggrid): Buttons cell renderer and ag-grid v32 update.

Packages: @lowdefy/blocks-aggrid

New cell.type: buttons renderer — render a list of action buttons in a column with each button firing its own block-level event with the row data on the payload. Per-button properties mirror the antd Button block (title, icon, type, variant, color, size, shape, danger, ghost, hideTitle, disabled) plus row-data-path variants (titleField, iconField, disabledField, hiddenField) for per-row state. Use this for inline Edit/Delete/Approve actions without _if dispatching.

ag-grid updated to v32.3.9 — pulls in two majors of upstream fixes. The column header UX (hamburger column menu with filter popup) is preserved by default; opt into the new ag-grid v32 column menu via columnMenu: 'new' on the block.

Cell focus suppressed by default — suppressCellFocus now defaults to true so the keyboard focus outline doesn't visually compete with built-in cell renderers (tags, buttons, links). Override with suppressCellFocus: false if needed. Cell overflow is also clipped so flex-rendered content stays inside its column.

feat(blocks-aggrid): Tag cell renders one tag per item for array-valued fields.

Packages: @lowdefy/blocks-aggrid

The cell.type: tag renderer now accepts an array of strings in addition to a single string. Each item is rendered as its own styled tag and resolves its colour through the existing colorMap / colorFrom / default configuration. Empty arrays and arrays containing only null/empty entries render the em-dash placeholder, matching the existing null-value behaviour. Single-string values are unchanged.

feat(blocks-aggrid): Auto-colour tag cells by default for consistent per-value colouring.

Packages: @lowdefy/blocks-aggrid

When a cell.type: tag column is used with no colorMap, no colorFrom, and no default, tag values are now coloured from a stable hash so the same value always gets the same colour across rows, columns, and tables. The palette uses 12 antd named hues (red, volcano, orange, gold, yellow, lime, green, cyan, blue, geekblue, purple, magenta) and respects the active theme.

The grey fallback is still available — set cell: { type: tag, default: default } on any column to opt out. When colorMap, colorFrom, or default is set, behaviour is unchanged.

Fixes & Improvements

• fix(blocks-antd): Add default header border to PageHeaderMenu. (@lowdefy/blocks-antd)

  PageHeaderMenu now has a default borderBottom matching the existing default borders on PageSiderMenu and PageSidebarLayout, for visual consistency across the page menu blocks. The default can still be overridden via styles.header.

• fix(blocks-markdown): Declare antd as a peer dependency. (@lowdefy/blocks-markdown)

  MarkdownWithCode imports antd for theme-aware syntax highlighting but the package did not declare antd in its peerDependencies, causing module resolution failures (e.g., when bundling apps that include @lowdefy/blocks-markdown without already pulling in antd). Added antd (>=6) as a peer dependency to match the version range used by @lowdefy/blocks-antd.