🔗 Using server side events with Req

Mix.install([
  {:req, "~> 0.5"},
  {:req_sse, github: "wojtekmach/req_sse"}
])

api_key = System.fetch_env!("CLAUDE_API_KEY")

Req.post!(
  "https://api.anthropic.com/v1/messages",
  headers: [
    anthropic_version: "2023-06-01",
    x_api_key: System.fetch_env!("CLAUDE_API_KEY")
  ],
  json: %{
    model: "claude-3-5-sonnet-20241022",
    max_tokens: 1024,
    messages: [%{role: "user", content: "What is 1 + 2?"}],
    stream: true
  },
  plugins: [ReqSSE],
  sse: [
    events: fn events, {req, resp} ->
      for event <- events, event.event == "content_block_delta" do
        IO.inspect(Jason.decode!(event.data))
      end
      {:cont, {req, resp}}
    end
  ]
)

$ elixir claude.exs
%{
  "delta" => %{"text" => "1 + 2", "type" => "text_delta"},
  "index" => 0,
  "type" => "content_block_delta"
}
%{
  "delta" => %{"text" => " = 3", "type" => "text_delta"},
  "index" => 0,
  "type" => "content_block_delta"
}