Struct ExternalWorkflow 

pub struct ExternalWorkflow {
    pub continuation: Arc<WorkflowContinuation>,
    pub task_index: Arc<TaskIndex>,
    pub workflow_id: Arc<str>,
    pub metadata_json: Option<Arc<str>>,
}

Workflow definition for binding-friendly worker API.

Contains only the structural information (definition hash + continuation tree) needed by PooledWorker for position tracking, completion detection, retry policies, and timeouts. Task execution is delegated to an external executor.

Fields

continuation: Arc<WorkflowContinuation>

The continuation tree describing the workflow structure.

task_index: Arc<TaskIndex>

Per-workflow TaskId → metadata index. Built once when the workflow is registered; replaces the O(N) tree walk + per-node SHA-256 that the worker would otherwise do for every task dispatch.

workflow_id: Arc<str>

Human-readable workflow name (for log/error display and FFI task executor).

metadata_json: Option<Arc<str>>

Optional JSON-encoded workflow-level metadata.