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Interface: ToolExecutionStartEvent

Defined in: lib/types/turn_runner.ts:138

Payload emitted on the observability bus when a tool's executor begins executing the handler.

Remarks

Fired after arg validation passes and immediately before the handler is called. callId is the cross-bus join key — equal to TurnToolCallContent.checksum and @nhtio/adk!ToolCall.checksum, not @nhtio/adk!ToolCall.id. Fires for both @nhtio/adk!Tool and @nhtio/adk!ArtifactTool invocations — the payload is identical.

Properties

PropertyTypeDescriptionDefined in
argsunknownThe validated arguments that will be passed to the handler.lib/types/turn_runner.ts:152
callIdstringCross-bus join key: sha256({ tool, args }), identical to TurnToolCallContent.checksum and @nhtio/adk!ToolCall.checksum. This is not @nhtio/adk!ToolCall.id. It collides by design for identical (tool, args) within a turn — that is what @nhtio/adk!DispatchContext.toolCallCount counts. Order or disambiguate repeated calls by startedAt. Empty string when not provided.lib/types/turn_runner.ts:150
startedAtDateTimeWhen execution started.lib/types/turn_runner.ts:154
toolNamestringName of the tool being executed.lib/types/turn_runner.ts:140
turnIdstringID of the turn in which the tool is being executed.lib/types/turn_runner.ts:142