ClaudeCodeSDK.Message (claude_code_sdk v0.0.1)

Represents a message from Claude Code CLI.

Messages are the core data structure returned by the Claude Code SDK. They represent different types of communication during a conversation with Claude, including system initialization, user inputs, assistant responses, and final results.

Message Types

:system - Session initialization messages with metadata
:user - User input messages (echoed back from CLI)
:assistant - Claude's response messages containing the actual AI output
:result - Final result messages with cost, duration, and completion status

Result Subtypes

:success - Successful completion
:error_max_turns - Terminated due to max turns limit
:error_during_execution - Error occurred during execution

System Subtypes

:init - Initial system message with session setup

Examples

# Assistant message
%ClaudeCodeSDK.Message{
  type: :assistant,
  subtype: nil,
  data: %{
    message: %{"content" => "Hello! How can I help?"},
    session_id: "session-123"
  }
}

# Result message
%ClaudeCodeSDK.Message{
  type: :result,
  subtype: :success,
  data: %{
    total_cost_usd: 0.001,
    duration_ms: 1500,
    num_turns: 2,
    session_id: "session-123"
  }
}

Summary

Types

message_type()

result_subtype()

system_subtype()

t()

Functions

error?(arg1)

Checks if the message indicates an error.

final?(arg1)

Checks if the message is a final result message.

from_json(json_string)

Parses a JSON message from Claude Code into a Message struct.

session_id(arg1)

Gets the session ID from a message.

Types

message_type()

@type message_type() :: :assistant | :user | :result | :system

result_subtype()

@type result_subtype() :: :success | :error_max_turns | :error_during_execution

system_subtype()

@type system_subtype() :: :init

t()

@type t() :: %ClaudeCodeSDK.Message{
  data: map(),
  raw: map(),
  subtype: result_subtype() | system_subtype() | nil,
  type: message_type()
}

Functions

error?(arg1)

Checks if the message indicates an error.

final?(arg1)

@spec final?(t()) :: boolean()

Checks if the message is a final result message.

Final messages indicate the end of a conversation or query.

Parameters

message - The message to check

Returns

true if the message is a final result, false otherwise.

Examples

iex> ClaudeCodeSDK.Message.final?(%ClaudeCodeSDK.Message{type: :result})
true

iex> ClaudeCodeSDK.Message.final?(%ClaudeCodeSDK.Message{type: :assistant})
false

from_json(json_string)

@spec from_json(String.t()) :: {:ok, t()} | {:error, term()}

Parses a JSON message from Claude Code into a Message struct.

Parameters

json_string - Raw JSON string from Claude CLI

Returns

{:ok, message} - Successfully parsed message
{:error, reason} - Parsing failed

Examples

iex> ClaudeCodeSDK.Message.from_json(~s({"type":"assistant","message":{"content":"Hello"}}))
{:ok, %ClaudeCodeSDK.Message{type: :assistant, ...}}

session_id(arg1)

Gets the session ID from a message.