message

type ExportConversation struct {
	Messages []ExportMessage `json:"messages"`
}

type ExportMessage struct {
	Role       string      `json:"role"`
	Content    string      `json:"content,omitempty"`
	Thinking   string      `json:"thinking,omitempty"`
	ToolCalls  []call.Call `json:"tool_calls,omitempty"`
	ToolName   string      `json:"tool_name,omitempty"`
	ToolCallID string      `json:"tool_call_id,omitempty"`
	CreatedAt  *time.Time  `json:"created_at,omitempty"`
}

type Image struct {
	Data []byte
}

type Images []Image

type Message struct {
	// ID uniquely identifies this message (for UI tracking).
	ID string
	// Role is the message sender (user, assistant, system, tool).
	Role roles.Role
	// Content is the main message text.
	Content string
	// Thinking contains reasoning or internal thought process.
	Thinking string `json:",omitempty"`
	// ThinkingSignature is an opaque signature for thinking blocks (Anthropic, Google).
	// Must be preserved unmodified when round-tripping multi-turn conversations.
	ThinkingSignature string `json:"thinking_signature,omitempty"`
	// Images contains attached images for vision models.
	Images Images `json:"images,omitempty"`
	// Calls contains tool invocation requests from the assistant.
	Calls []call.Call `json:"calls,omitempty"`
	// ToolName is the name of the tool that produced this result.
	ToolName string `json:"tool_name,omitempty"`
	// ToolCallID links this tool result to its original call.
	ToolCallID string `json:"tool_call_id,omitempty"`
	// Type classifies the message (Normal, Synthetic, Ephemeral, DisplayOnly, Bookmark, Metadata).
	Type Type `json:"type,omitempty"`
	// Parts contains ordered content for incremental UI rendering.
	Parts []part.Part `json:"-"`
	// Error is set if an error occurred during message generation.
	Error error `json:"-"`
	// Tokens holds per-message token counts (exact from API or estimated).
	Tokens Tokens `json:"tokens,omitzero"`
	// CreatedAt is when the message was created.
	CreatedAt time.Time `json:"created_at,omitzero"`
}

type Messages []Message

type Tokens struct {
	// Total is the overall token count for this message.
	// Assistant: exact from usageData.Output (API-reported).
	// Tool: delta-backfilled from API usage (exact).
	// User: estimated at creation time.
	Total int `json:"total,omitempty"`
	// Content is the estimated token count for the message content.
	// Populated via provider tokenizer (estimateTokens). Assistant messages only.
	Content int `json:"content,omitempty"`
	// Thinking is the estimated token count for the thinking/reasoning content.
	// Populated via provider tokenizer (estimateTokens). Assistant messages only.
	Thinking int `json:"thinking,omitempty"`
	// Tools is Total - Content - Thinking. Assistant messages only.
	// Captures the actual cost of tool call JSON, argument encoding, special tokens.
	// Derived as the exact remainder — avoids estimating structured JSON where estimation is worst.
	Tools int `json:"tools,omitempty"`
}

type Type int