Struct CreateMessageRequestParam 

pub struct CreateMessageRequestParam {
    pub max_tokens: u32,
    pub messages: Vec<SamplingMessage>,
    pub system_prompt: Option<String>,
    pub temperature: Option<f32>,
    pub stop_sequences: Option<Vec<String>>,
    pub model_preferences: Option<ModelPreferences>,
    pub include_context: Option<ContextInclusion>,
    pub tools: Option<Vec<Tool>>,
    pub tool_choice: Option<ToolChoice>,
    pub metadata: Option<Value>,
}

Create message request parameters (MCP 2025-11-25)

Parameters for requesting LLM sampling from the client.

Fields

max_tokens: u32

Maximum tokens to generate (required)

messages: Vec<SamplingMessage>

Conversation messages (required)

system_prompt: Option<String>

System prompt for the model

temperature: Option<f32>

Temperature for generation (0.0-1.0)

stop_sequences: Option<Vec<String>>

Stop sequences that will end generation

model_preferences: Option<ModelPreferences>

Model selection preferences

include_context: Option<ContextInclusion>

What server context to include

tools: Option<Vec<Tool>>

Tools available for the model to use (MCP 2025-11-25)

tool_choice: Option<ToolChoice>

How the model should use tools (MCP 2025-11-25)

metadata: Option<Value>

Additional request metadata

Implementations

impl CreateMessageRequestParam

pub fn simple(max_tokens: u32, user_message: impl Into<String>) -> Self

Create a simple text completion request

pub fn with_tools( max_tokens: u32, messages: Vec<SamplingMessage>, tools: Vec<Tool>, ) -> Self

Create a request with tools available (MCP 2025-11-25)

Trait Implementations

impl Clone for CreateMessageRequestParam

fn clone(&self) -> CreateMessageRequestParam

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CreateMessageRequestParam

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CreateMessageRequestParam

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for CreateMessageRequestParam

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

where __S: Serializer,

Serialize this value into the given Serde serializer.