Struct ClosureTool 

pub struct ClosureTool { /* private fields */ }

A tool defined by a closure function.

Created via ClosureTool::new_sync or ClosureTool::new_async. For ergonomic creation, use the macros or AgentBuilder’s custom_tool method.

Implementations

impl ClosureTool

pub fn new_sync( name: impl Into<String>, description: impl Into<String>, schema: Value, handler: impl Fn(Value, &ToolContext) -> Result<AgentToolResult, ToolError> + Send + Sync + 'static, ) -> Self

Create a new sync tool from a closure.

The closure receives (params: Value, ctx: &ToolContext).

pub fn new_async( name: impl Into<String>, description: impl Into<String>, schema: Value, handler: impl Fn(Value, &ToolContext) -> Pin<Box<dyn Future<Output = Result<AgentToolResult, ToolError>> + Send>> + Send + Sync + 'static, ) -> Self

Create a new async tool from a closure.

The closure receives (params: Value, ctx: &ToolContext) and returns a Future.

Trait Implementations

impl AgentTool for ClosureTool

fn name(&self) -> &str

Tool name (used in function calls)

fn label(&self) -> &str

Human-readable label

fn description(&self) -> &str

Description for the model

fn parameters_schema(&self) -> Value

JSON Schema for parameters

fn execute<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, _tool_call_id: &'life1 str, params: Value, _signal: Option<Receiver<()>>, ctx: &'life2 ToolContext, ) -> Pin<Box<dyn Future<Output = Result<AgentToolResult, ToolError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Execute the tool with the given tool call ID and parameters.

fn essential(&self) -> bool

Whether this tool is essential (cannot be disabled). Essential tools: read, write, edit, bash, grep, find, ls Optional tools: web_search, github, subagent, etc.

fn on_progress(&self, _callback: Arc<dyn Fn(String) + Send + Sync>)

Called with progress updates during execution. Tools can override this to emit streaming updates.

fn on_browse_progress( &self, _callback: Arc<dyn Fn(BrowseProgress) + Send + Sync>, )

Structured browse progress callback for browser tool context enrichment. Default implementation is no-op. Only browse tools override this to register a callback that enriches ToolCallContext with structured data from BrowseProgress events.

fn render_call(&self, _params: &Value) -> Option<RenderOutput>

Custom rendering for tool call (TUI visualization). Return None to use the default tool_renderer.rs formatter.

fn render_result(&self, _result: &AgentToolResult) -> Option<RenderOutput>

Custom rendering for tool result (TUI visualization). Return None to use the default tool_renderer.rs formatter.

fn intent(&self) -> Option<&str>

Intent trace — a concise description of what this tool does. Returned value is included in ToolExecutionStart / ToolExecutionEnd events so the agent loop can surface intent to users or telemetry. Default None (no intent tracing).

fn execution_mode(&self) -> ToolExecutionMode

Execution mode for parallel safety. Defaults to ParallelSafe. Override for file-mutating or sequential tools.

fn tool_tier(&self) -> ToolTier

Risk tier for approval gating.

fn current_tab_id(&self) -> Option<Uuid>

Return the current active tab ID, if this tool manages browser tabs. Defaults to None. Browser tools override this to return the tab ID of the currently-open tab during execution, so the agent loop can populate ToolExecutionUpdate.tab_id.

fn set_tab_id_slot(&self, _slot: Arc<Mutex<RawMutex, Option<Uuid>>>)

Receive a shared slot where the tool can write the current tab ID. The agent loop creates the slot and passes it before on_progress; the tool writes Some(tab_id) when it opens a tab and None when it closes it. Defaults to a no-op — only tab-aware tools override.

fn to_definition(&self) -> ToolDefinition

Convert to ToolDefinition