Behaviour for MCP prompts.

Prompts are reusable prompt templates that can be retrieved and filled with arguments.

Example

defmodule MyApp.MCP.Prompts.FixIssue do
  @behaviour Excessibility.MCP.Prompt

  @impl true
  def name, do: "fix-issue"

  @impl true
  def description, do: "Generate a prompt for fixing accessibility issues"

  @impl true
  def arguments do
    [
      %{
        "name" => "issue",
        "description" => "The accessibility issue to fix",
        "required" => true
      },
      %{
        "name" => "element",
        "description" => "The HTML element causing the issue",
        "required" => false
      }
    ]
  end

  @impl true
  def get(args) do
    issue = Map.get(args, "issue", "unknown issue")
    element = Map.get(args, "element")

    content = if element do
      "Fix this accessibility issue: #{issue}\n\nElement: #{element}"
    else
      "Fix this accessibility issue: #{issue}"
    end

    {:ok, %{
      "messages" => [
        %{
          "role" => "user",
          "content" => %{
            "type" => "text",
            "text" => content
          }
        }
      ]
    }}
  end
end

Callbacks

• name/0 - String identifier for this prompt
• description/0 - Human-readable description
• arguments/0 - List of argument definitions
• get/1 - Returns the prompt content given arguments