Enum MessageContent 

pub enum MessageContent {
    Text(String),
    AssistantWithToolCalls {
        text: Option<String>,
        tool_calls: Vec<ToolCall>,
        reasoning_content: Option<String>,
        thinking_blocks: Vec<ThinkingBlock>,
    },
    ToolResult(ToolResult),
    ToolResultRef(ToolResultRef),
    MultiPart {
        text: Option<String>,
        images: Vec<ImagePart>,
    },
}

Variants

Text(String)

AssistantWithToolCalls

Fields

text: Option<String>

tool_calls: Vec<ToolCall>

reasoning_content: Option<String>

Thinking-model reasoning captured alongside the tool_calls. Some provider APIs (Moonshot Kimi K2-thinking / K2.6, MiniMax-M2 when reasoning_split is on) require the historical reasoning_content to be echoed back on every assistant tool_call message or they reject the next request with a 400. DeepSeek-R1 is the opposite — it rejects the request if this field is echoed back. The send-side ReasoningPolicy (per-provider) decides whether to emit. Always captured on the receive side so we don’t lose data.

thinking_blocks: Vec<ThinkingBlock>

Anthropic-style extended-thinking blocks received alongside this turn. Carries the cryptographic signature that Claude (and Anthropic-compatible proxies routing models like deepseek-v4-pro through claude.rs) require us to echo verbatim on every subsequent request. Empty when the upstream isn’t Anthropic or thinking was disabled. provider/claude.rs::format_messages emits these as the first elements of the content array.

ToolResult(ToolResult)

ToolResultRef(ToolResultRef)

Lightweight reference to a tool result whose full output is cached on disk. Used for new tool results; old ToolResult variant kept for backward compat.

MultiPart

User message with text and/or image attachments (vision models).

Fields

text: Option<String>

images: Vec<ImagePart>

Trait Implementations

impl Clone for MessageContent

fn clone(&self) -> MessageContent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MessageContent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MessageContent

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for MessageContent

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.