message

Documentation

Index

• func MarshalParts(parts []ContentPart) ([]byte, error)
• type ContentPart
  • func UnmarshalParts(data []byte) ([]ContentPart, error)
• type Finish
• type ImageContent
• type Message
  • func FromFantasyMessage(msg fantasy.Message) Message
  • func (m *Message) AddPart(part ContentPart)
  • func (m *Message) AddToolCall(tc ToolCall)
  • func (m *Message) Content() string
  • func (m *Message) Images() []ImageContent
  • func (m *Message) Reasoning() ReasoningContent
  • func (m *Message) ToFantasyMessages() []fantasy.Message
  • func (m *Message) ToolCalls() []ToolCall
  • func (m *Message) ToolResults() []ToolResult
• type MessageRole
• type ReasoningContent
• type TextContent
• type ToolCall
• type ToolResult

Functions

func MarshalParts

func MarshalParts(parts []ContentPart) ([]byte, error)

MarshalParts serializes a slice of ContentPart to JSON using type-tagged wrappers. Each part becomes {"type":"...", "data":{...}}.

Types

type ContentPart

type ContentPart interface {
	// contains filtered or unexported methods
}

ContentPart is the marker interface for all message content block types. A message contains a heterogeneous slice of ContentPart values, enabling rich structured messages that carry text, reasoning, tool calls, tool results, and finish markers in a single message.

func UnmarshalParts

func UnmarshalParts(data []byte) ([]ContentPart, error)

UnmarshalParts deserializes type-tagged JSON back into a slice of ContentPart.

type Finish

type Finish struct {
	Reason string `json:"reason"` // "end_turn", "tool_use", "max_tokens", etc.
}

Finish marks the end of an assistant turn, carrying the stop reason.

type ImageContent

type ImageContent struct {
	Data      []byte `json:"data"`
	MediaType string `json:"media_type"`
}

ImageContent holds image data within a message. The data is stored as raw bytes (not base64-encoded); serialization handles encoding. MediaType is a MIME type such as "image/png" or "image/jpeg".

type Message

type Message struct {
	ID        string        `json:"id"`
	Role      MessageRole   `json:"role"`
	Parts     []ContentPart `json:"parts"`
	Model     string        `json:"model,omitempty"`
	Provider  string        `json:"provider,omitempty"`
	CreatedAt time.Time     `json:"created_at"`
	UpdatedAt time.Time     `json:"updated_at"`
}

Message is a single conversation message containing a heterogeneous slice of ContentPart blocks. This design (borrowed from crush) enables a single assistant message to carry text, reasoning, and multiple tool calls as discrete, typed blocks rather than flattening everything into strings.

func FromFantasyMessage

func FromFantasyMessage(msg fantasy.Message) Message

FromFantasyMessage converts a fantasy.Message into our Message type, extracting all content parts into the appropriate block types.

func (*Message) AddPart

func (m *Message) AddPart(part ContentPart)

AddPart appends a content part and updates the timestamp.

func (*Message) AddToolCall

func (m *Message) AddToolCall(tc ToolCall)

AddToolCall appends or updates a ToolCall part. If a call with the same ID already exists, it is replaced (supports streaming where partial calls arrive before the final version).

func (*Message) Content

func (m *Message) Content() string

Content returns the concatenated text from all TextContent parts.

func (*Message) Images

func (m *Message) Images() []ImageContent

Images returns all ImageContent parts from this message.

func (*Message) Reasoning

func (m *Message) Reasoning() ReasoningContent

Reasoning returns the ReasoningContent if present, or a zero value.

func (*Message) ToFantasyMessages

func (m *Message) ToFantasyMessages() []fantasy.Message

ToFantasyMessages converts a Message to one or more fantasy.Message values. An assistant message with tool calls produces a single fantasy message with mixed TextPart and ToolCallPart content. Tool-role messages produce ToolResultPart entries.

func (*Message) ToolCalls

func (m *Message) ToolCalls() []ToolCall

ToolCalls returns all ToolCall parts from this message.

func (*Message) ToolResults

func (m *Message) ToolResults() []ToolResult

ToolResults returns all ToolResult parts from this message.

type MessageRole

type MessageRole string

MessageRole identifies the sender of a message.

const (
	RoleUser      MessageRole = "user"
	RoleAssistant MessageRole = "assistant"
	RoleTool      MessageRole = "tool"
	RoleSystem    MessageRole = "system"
)

type ReasoningContent

type ReasoningContent struct {
	Thinking  string `json:"thinking"`
	Signature string `json:"signature,omitempty"` // Anthropic
}

ReasoningContent holds extended thinking / reasoning output from the LLM. Provider-specific metadata (signatures, etc.) is preserved for round-trip fidelity when the conversation is sent back to the provider.

type TextContent

type TextContent struct {
	Text string `json:"text"`
}

TextContent holds plain text content within a message.

type ToolCall

type ToolCall struct {
	ID       string `json:"id"`
	Name     string `json:"name"`
	Input    string `json:"input"` // JSON string of arguments
	Finished bool   `json:"finished"`
}

ToolCall represents a tool invocation initiated by the LLM. It is stored as a content part within an assistant message, not as a separate message.

type ToolResult

type ToolResult struct {
	ToolCallID string `json:"tool_call_id"`
	Name       string `json:"name"`
	Content    string `json:"content"`
	IsError    bool   `json:"is_error"`
}

ToolResult represents the result of executing a tool. It is stored as a content part within a tool-role message, linked to a ToolCall by ID.