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ag-ui-protocol

ag-ui-protocol

github.com/meetsmoreDevelopment1185 installsUpdated today
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About ag-ui-protocol

AG-UI Protocol is an open, event-based protocol for communication between AI agents and user-facing applications. This skill provides protocol documentation for developers implementing event flows, state synchronization, tool calls, and message streaming.

Key features

  1. 01Event types and patterns
  2. 02Message structures and roles
  3. 03Tool definitions and call lifecycle
  4. 04State snapshots and incremental sync
  5. 05Server and client quickstarts

Use cases

  1. 01Implement event communication between agents and frontends
  2. 02Build message and tool-call streams
  3. 03Debug state synchronization and event flows

Install

Copy the command and run it in a terminal.

$npx skills add https://github.com/meetsmore/use-ai --skill ag-ui-protocol

After installing, type/ag-ui-protocolin Claude Code to confirm it loaded.

Bundled files

References and scripts installed along with SKILL.md.

docs/2025-11-27/
introduction.md
docs/2025-11-27/concepts/
agents.md
architecture.md
events.md
messages.md
middleware.md
serialization.md
state.md
tools.md
docs/2025-11-27/quickstart/
clients.md
introduction.md
server.md

Details

From the project README

AG-UI Protocol

The Agent-User Interaction (AG-UI) Protocol is an open, lightweight, event-based protocol that standardizes how AI agents connect to user-facing applications.

When to Use This Skill

Use this skill when:

  • Implementing AG-UI protocol events in your code
  • Building agents that communicate with frontends via AG-UI
  • Understanding the event types and their structure
  • Implementing state management, tool calls, or message streaming
  • Debugging AG-UI event flows

Documentation

See the docs/2025-11-27/ directory for complete AG-UI protocol documentation:

  • introduction.md - Protocol overview and integrations
  • concepts/architecture.md - Core architecture and design
  • concepts/events.md - Event types and patterns
  • concepts/messages.md - Message structure and types
  • concepts/state.md - State management and synchronization
  • concepts/tools.md - Tool definitions and lifecycle
  • concepts/agents.md - Agent implementation
  • concepts/middleware.md - Middleware patterns
  • concepts/serialization.md - Event serialization and compaction
  • quickstart/introduction.md - Getting started guide
  • quickstart/server.md - Server implementation
  • quickstart/clients.md - Client implementation

Quick Reference

Event Types
enum EventType {
  // Lifecycle
  RUN_STARTED = "RUN_STARTED",
  RUN_FINISHED = "RUN_FINISHED",
  RUN_ERROR = "RUN_ERROR",
  STEP_STARTED = "STEP_STARTED",
  STEP_FINISHED = "STEP_FINISHED",

  // Text Messages
  TEXT_MESSAGE_START = "TEXT_MESSAGE_START",
  TEXT_MESSAGE_CONTENT = "TEXT_MESSAGE_CONTENT",
  TEXT_MESSAGE_END = "TEXT_MESSAGE_END",

  // Tool Calls
  TOOL_CALL_START = "TOOL_CALL_START",
  TOOL_CALL_ARGS = "TOOL_CALL_ARGS",
  TOOL_CALL_END = "TOOL_CALL_END",

  // State
  STATE_SNAPSHOT = "STATE_SNAPSHOT",
  STATE_DELTA = "STATE_DELTA",
  MESSAGES_SNAPSHOT = "MESSAGES_SNAPSHOT",

  // Custom
  RAW = "RAW",
  CUSTOM = "CUSTOM",
}
Event Patterns
  1. Start-Content-End: Streams content incrementally (text, tool arguments)
  2. Snapshot-Delta: State synchronization using complete snapshots + JSON Patch updates
  3. Lifecycle: Run monitoring with mandatory start/end events
Message Roles
  • user - User messages (text and multimodal)
  • assistant - AI responses (text and tool calls)
  • system - Instructions or context
  • tool - Tool execution results
  • activity - Progress updates
  • developer - Internal debugging
Tool Definition Structure
interface Tool {
  name: string;           // Unique identifier
  description: string;    // Purpose explanation
  parameters: JSONSchema; // Accepted arguments
}
Tool Call Lifecycle
  1. TOOL_CALL_START - Initiates with unique ID
  2. TOOL_CALL_ARGS - Streams JSON arguments
  3. TOOL_CALL_END - Marks completion
State Synchronization
  • STATE_SNAPSHOT - Complete state replacement
  • STATE_DELTA - Incremental JSON Patch (RFC 6902) updates

Source

Documentation downloaded from: https://github.com/ag-ui-protocol/ag-ui/tree/main/docs

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