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Execution State

ThreadState.execution is present while a thread is actively running (during tool calls, hook invocations, sub-prompts) and null when the thread is at rest (from endpoints, external callers). Execution state carries step counts, the active dual-side, cancellation, and controls for stopping or forcing turns.

For everything else about threads, see Threads.

1. Availability

The execution property is:

  • Present during active execution (tools, hooks)
  • Null when accessing at rest (endpoints)
if (state.execution) {
  console.log(`Step ${state.execution.stepCount}`);
}

2. Execution Properties

PropertyTypeDescription
flowIdstringUnique execution ID
currentSide'a' | 'b'Active side (dual_ai)
stepCountnumberTotal LLM request/response cycles
sideAStepCountnumberSide A steps
sideBStepCountnumberSide B steps
stoppedbooleanExecution stopped
stoppedBy'a' | 'b' | undefinedWho stopped
messageHistoryMessage[]Current history
abortSignalAbortSignalCancellation signal
promptPathstring[]Path from root to current prompt

2.1 Prompt Path

The promptPath property tracks the current position in the prompt hierarchy:

  • At root level: ['my_prompt']
  • Inside a sub-prompt: ['my_prompt', 'sub_prompt']
  • After handoff: ['new_agent_prompt']

This allows tools and hooks to understand their execution context depth.

3. Controlling Execution

// Force next turn to a specific side (dual_ai only)
state.execution.forceTurn('b');

// Stop execution after current operation
state.execution.stop();

// Use abort signal for cancellation
fetch(url, { signal: state.execution.abortSignal });

4. TypeScript Reference

interface ExecutionState {
  readonly flowId: string;
  readonly currentSide: 'a' | 'b';
  readonly stepCount: number;
  readonly sideAStepCount: number;
  readonly sideBStepCount: number;
  readonly stopped: boolean;
  readonly stoppedBy?: 'a' | 'b';
  readonly messageHistory: Message[];
  readonly abortSignal: AbortSignal;
  readonly promptPath: string[];
  forceTurn(side: 'a' | 'b'): void;
  stop(): void;
}