|
| 1 | +--- |
| 2 | +title: "Elixir SDK Overview" |
| 3 | +description: "Connect to AG-UI agents using the community Elixir SDK (ag_ui_ex)" |
| 4 | +--- |
| 5 | + |
| 6 | +The AG-UI Elixir SDK (`ag_ui_ex`) provides a complete, idiomatic Elixir implementation of the AG-UI protocol. It includes typed event structs, SSE and Phoenix Channel transports, a composable middleware pipeline, GenServer-based state management with RFC 6902 JSON Patch, and an HTTP client for consuming AG-UI event streams. |
| 7 | + |
| 8 | +## Installation |
| 9 | + |
| 10 | +Add `ag_ui_ex` to your dependencies in `mix.exs`: |
| 11 | + |
| 12 | +```elixir |
| 13 | +def deps do |
| 14 | + [ |
| 15 | + {:ag_ui_ex, "~> 0.1.0"} |
| 16 | + ] |
| 17 | +end |
| 18 | +``` |
| 19 | + |
| 20 | +Then fetch dependencies: |
| 21 | + |
| 22 | +```bash |
| 23 | +mix deps.get |
| 24 | +``` |
| 25 | + |
| 26 | +## Quick Start |
| 27 | + |
| 28 | +### Emit Events |
| 29 | + |
| 30 | +```elixir |
| 31 | +alias AgUi.Core.Events |
| 32 | + |
| 33 | +# Create a run started event |
| 34 | +event = %Events.RunStarted{ |
| 35 | + run_id: "run-001", |
| 36 | + thread_id: "thread-001", |
| 37 | + timestamp: DateTime.utc_now() |> DateTime.to_unix(:millisecond) |
| 38 | +} |
| 39 | + |
| 40 | +# Encode as SSE |
| 41 | +{:ok, sse_data} = AgUi.Encoder.EventEncoder.encode(event) |
| 42 | +``` |
| 43 | + |
| 44 | +### SSE Transport (Plug / Phoenix) |
| 45 | + |
| 46 | +```elixir |
| 47 | +# In your Phoenix router |
| 48 | +forward "/ag-ui/events", AgUi.Transport.SSE |
| 49 | + |
| 50 | +# Or use directly in a controller |
| 51 | +def stream(conn, _params) do |
| 52 | + AgUi.Transport.SSE.stream_events(conn, fn send_fn -> |
| 53 | + send_fn.(%Events.RunStarted{run_id: "run-001"}) |
| 54 | + Process.sleep(100) |
| 55 | + send_fn.(%Events.RunFinished{run_id: "run-001"}) |
| 56 | + end) |
| 57 | +end |
| 58 | +``` |
| 59 | + |
| 60 | +### Channel Transport (Phoenix WebSocket) |
| 61 | + |
| 62 | +```elixir |
| 63 | +defmodule MyApp.AgUiChannel do |
| 64 | + use Phoenix.Channel |
| 65 | + use AgUi.Transport.Channel |
| 66 | + |
| 67 | + def join("ag_ui:" <> _scope, _payload, socket) do |
| 68 | + {:ok, socket} |
| 69 | + end |
| 70 | +end |
| 71 | +``` |
| 72 | + |
| 73 | +### State Management |
| 74 | + |
| 75 | +```elixir |
| 76 | +# Start the state manager |
| 77 | +{:ok, pid} = AgUi.State.Manager.start_link(name: :my_agent_state) |
| 78 | + |
| 79 | +# Set state |
| 80 | +AgUi.State.Manager.set(pid, %{status: "running", progress: 0}) |
| 81 | + |
| 82 | +# Apply a JSON Patch delta (RFC 6902) |
| 83 | +AgUi.State.Manager.patch(pid, [ |
| 84 | + %{"op" => "replace", "path" => "/progress", "value" => 75} |
| 85 | +]) |
| 86 | + |
| 87 | +# Read current state |
| 88 | +{:ok, state} = AgUi.State.Manager.get(pid) |
| 89 | +# => %{status: "running", progress: 75} |
| 90 | +``` |
| 91 | + |
| 92 | +### Middleware Pipeline |
| 93 | + |
| 94 | +```elixir |
| 95 | +alias AgUi.Middleware.Pipeline |
| 96 | + |
| 97 | +pipeline = |
| 98 | + Pipeline.new() |
| 99 | + |> Pipeline.add(&Pipeline.add_timestamp/2) |
| 100 | + |> Pipeline.add(&Pipeline.validate_type/2) |
| 101 | + |
| 102 | +{:ok, processed_event} = Pipeline.run(pipeline, event) |
| 103 | +``` |
| 104 | + |
| 105 | +### HTTP Client |
| 106 | + |
| 107 | +```elixir |
| 108 | +# Consume an AG-UI event stream over SSE |
| 109 | +{:ok, _client} = AgUi.Client.HttpAgent.start_link( |
| 110 | + url: "http://localhost:4000/ag-ui/events", |
| 111 | + handler: fn event -> IO.inspect(event, label: "AG-UI Event") end |
| 112 | +) |
| 113 | +``` |
| 114 | + |
| 115 | +## Package Structure |
| 116 | + |
| 117 | +### Core (`AgUi.Core`) |
| 118 | + |
| 119 | +Defines all 30+ typed event structs with validation. Events are organized by category: |
| 120 | + |
| 121 | +| Category | Events | |
| 122 | +|:---------|:-------| |
| 123 | +| Lifecycle | `RunStarted`, `RunFinished`, `RunError` | |
| 124 | +| Progress | `StepStarted`, `StepFinished` | |
| 125 | +| Text | `TextMessageStart`, `TextMessageContent`, `TextMessageEnd` | |
| 126 | +| Thinking | `ThinkingTextMessageStart`, `ThinkingTextMessageContent`, `ThinkingTextMessageEnd`, `ThinkingStart`, `ThinkingEnd` | |
| 127 | +| Tools | `ToolCallStart`, `ToolCallArgs`, `ToolCallEnd` | |
| 128 | +| State | `StateSnapshot`, `StateDelta` | |
| 129 | +| Messages | `MessagesSnapshot` | |
| 130 | +| Activity | `ActivitySnapshot`, `ActivityDelta` | |
| 131 | +| Reasoning | `ReasoningStart`, `ReasoningMessageStart`, `ReasoningMessageContent`, `ReasoningMessageEnd`, `ReasoningMessageChunk`, `ReasoningEnd` | |
| 132 | +| Other | `EncryptedValue`, `Raw`, `Custom` | |
| 133 | + |
| 134 | +### Encoder (`AgUi.Encoder`) |
| 135 | + |
| 136 | +SSE and JSON encoding/decoding with automatic camelCase ↔ snake_case conversion. |
| 137 | + |
| 138 | +```elixir |
| 139 | +{:ok, sse_string} = AgUi.Encoder.EventEncoder.encode(event) |
| 140 | +{:ok, event_struct} = AgUi.Encoder.EventEncoder.decode(sse_string) |
| 141 | +``` |
| 142 | + |
| 143 | +### Transports (`AgUi.Transport`) |
| 144 | + |
| 145 | +- **`AgUi.Transport.SSE`** — Plug-compatible SSE handler for streaming events to browser clients |
| 146 | +- **`AgUi.Transport.Channel`** — Phoenix Channel macros for WebSocket-based event streaming |
| 147 | + |
| 148 | +### State (`AgUi.State`) |
| 149 | + |
| 150 | +GenServer-backed state manager using a snapshot/delta pattern with full RFC 6902 JSON Patch support via the `json_patch` library. |
| 151 | + |
| 152 | +### Middleware (`AgUi.Middleware`) |
| 153 | + |
| 154 | +Composable pipeline for event processing. Ships with built-in middleware for timestamp injection and type validation. Add custom middleware with any `(event, opts) -> {:ok, event} | {:error, reason}` function. |
| 155 | + |
| 156 | +### Client (`AgUi.Client`) |
| 157 | + |
| 158 | +`AgUi.Client.HttpAgent` — A GenServer that connects to a remote AG-UI event stream over HTTP SSE and dispatches events to a handler function. |
| 159 | + |
| 160 | +## Requirements |
| 161 | + |
| 162 | +- Elixir ~> 1.15 |
| 163 | +- Erlang/OTP ~> 26 |
| 164 | + |
| 165 | +## Source & Package |
| 166 | + |
| 167 | +- **Hex.pm**: [hex.pm/packages/ag_ui_ex](https://hex.pm/packages/ag_ui_ex) |
| 168 | +- **GitHub**: [github.com/peguesj/ag_ui_ex](https://github.com/peguesj/ag_ui_ex) |
| 169 | +- **License**: MIT |
0 commit comments