Struct ToolCall 

pub struct ToolCall {
    pub id: String,
    pub name: String,
    pub arguments: String,
}

A tool call requested by the model.

The model requests a tool call via the tool_calls field of Message::Assistant; after the agent loop executes it, the result is passed back as a Message::ToolResult message right after, paired with this call by id (which disambiguates multiple calls to the same-named tool in one turn).

Example

Construct a tool request and pair it with the returned execution result (in real flows the request is generated by the model and passed back automatically after the loop executes it):

use molo::{Message, ToolCall};

let request = Message::Assistant {
    content: String::new(),
    reasoning: None,
    tool_calls: vec![ToolCall {
        id: "call_1".into(),
        name: "weather".into(),
        arguments: r#"{"city":"Beijing"}"#.into(),
    }],
};
let result = Message::tool_result("call_1", "Sunny, 23°C");

let Message::Assistant { tool_calls, .. } = &request else {
    panic!("expected an assistant message");
};
assert_eq!(tool_calls[0].id, "call_1");
assert_eq!(result, Message::tool_result("call_1", "Sunny, 23°C"));

Fields

id: String

Unique id of this call; the execution result is paired with it via the id of Message::ToolResult.

name: String

Tool name, matching the name of the tool definition Tool::schema.

arguments: String

Model-generated arguments (JSON text), parsed by the agent loop and handed to the tool for execution.

Trait Implementations

impl Clone for ToolCall

fn clone(&self) -> ToolCall

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ToolCall

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ToolCall

fn deserialize<__D>( __deserializer: __D, ) -> Result<ToolCall, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ToolCall

impl Hash for ToolCall

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ToolCall

fn eq(&self, other: &ToolCall) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ToolCall

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ToolCall