Struct BeforeToolCallResult 

pub struct BeforeToolCallResult {
    pub block: bool,
    pub reason: Option<String>,
    pub terminate: bool,
    pub args: Option<Value>,
}

Result of a before_tool_call hook. block prevents execution; the loop emits an error tool result with reason (or a default) instead. terminate participates in the batch early-termination rule (all results must set it).

args is the Rust equivalent of TS beforeToolCall mutating the validated args object in place: JS callbacks receive args by reference and write to it; Rust hands the hook an immutable &serde_json::Value, so to rewrite the args the hook returns them here. Replacement args are applied without re-validation — mirroring TS, where the mutation happens after validateToolArguments and is never re-checked. None keeps the validated args.

Fields

block: bool

reason: Option<String>

terminate: bool

args: Option<Value>

Trait Implementations

impl Clone for BeforeToolCallResult

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BeforeToolCallResult

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

Formats the value using the given formatter.

impl Default for BeforeToolCallResult

fn default() -> Self

Returns the “default value” for a type.