Async Handoffs

Use start_workflows() when a workflow needs to hand discovered work off to independent top-level workflows instead of keeping everything inside one run.

If you are explicitly modelling agent runs, start_agents() and wait_for_agents() are semantic aliases with agent-oriented defaults.

For larger end-to-end examples, see Agent Orchestration.

This is useful for agent-style orchestration:

• a planner workflow discovers tasks at runtime
• each task becomes its own durable workflow
• the parent stores those workflow IDs in state
• the parent can later wait for all, any, quorum, or a named started group

The ->start_workflows() method

use Queuety\Enums\WaitMode;
use Queuety\Queuety;

$agent_task = Queuety::workflow( 'agent_task' )
    ->then( ResearchTopicStep::class )
    ->then( SummarizeTopicStep::class );

Queuety::workflow( 'brief_research' )
    ->then( PlanTopicsStep::class )
    ->start_workflows(
        items_key: 'topics',
        workflow_builder: $agent_task,
        result_key: 'child_workflow_ids',
        group_key: 'researchers',
    )
    ->wait_for_workflow_group( 'researchers', WaitMode::All, result_key: 'child_results' )
    ->then( SynthesizeBriefStep::class )
    ->dispatch( [ 'brief_id' => 42 ] );

In that example:

1. PlanTopicsStep writes an array of topic payloads to $state['topics']
2. start_workflows() dispatches one agent_task workflow per topic
3. the started workflow IDs are written to $state['child_workflow_ids']
4. wait_for_workflow_group() pauses until that started group satisfies the chosen completion condition
5. SynthesizeBriefStep receives the completed child states under $state['child_results']

Child payloads

Each item in items_key becomes the initial payload for one started workflow.

If the item is an array, its public keys are merged into the child payload:

[
    [ 'topic' => 'pricing', 'source' => 'competitors' ],
    [ 'topic' => 'reviews', 'source' => 'customers' ],
]

If the item is scalar, Queuety stores it under payload_key:

->start_workflows(
    items_key: 'topic_names',
    workflow_builder: $agent_task,
    payload_key: 'topic',
)

Inheriting parent state

By default, start_workflows() merges the parent workflow's public state into every child payload.

That means shared context such as brief_id, account_id, or campaign is automatically available in each started workflow.

The source items_key and the result_key are excluded from inheritance so each child does not receive the whole task list or the final workflow ID array.

Set inherit_state: false when each child should receive only its item payload.

Why not run_workflow()?

run_workflow() creates a parent-child relationship where the parent parks on that step until the child completes.

start_workflows() is looser:

• the started workflows are independent top-level workflows
• each started workflow can be inspected, retried, or exported on its own
• the parent decides later whether and how to wait on them

That makes start_workflows() a better fit for async agent task handoff, while run_workflow() remains the better fit for nested composition inside one orchestration tree.

Waiting later

start_workflows() is designed to pair with Workflow Dependencies:

use Queuety\Enums\WaitMode;

Queuety::workflow( 'review_board' )
    ->start_workflows( 'review_tasks', $review_task_workflow, 'review_workflow_ids' )
    ->wait_for_workflows( 'review_workflow_ids', WaitMode::Any, 'winner' )
    ->then( FinalizeDecisionStep::class )
    ->dispatch( $payload );

• WaitMode::All collects all completed child states
• WaitMode::Any resumes on the first successful child workflow

This gives you planner/executor orchestration without needing a full runtime-editable DAG engine.

Agent-friendly aliases

start_agents() is an alias for start_workflows() with defaults tuned for planner/executor flows:

• result_key defaults to agent_workflow_ids
• payload_key defaults to agent_task
• name defaults to start_agents

wait_for_agents() is an alias for wait_for_workflows() with defaults tuned for collecting agent results:

• workflows defaults to agent_workflow_ids
• result_key defaults to agent_results
• name defaults to wait_for_agents

wait_for_agent_group() is an alias for wait_for_workflow_group() with defaults tuned for agent batches.

use Queuety\Enums\WaitMode;

$agent_run = Queuety::workflow( 'agent_run' )
    ->then( ResearchTopicStep::class )
    ->then( SummarizeTopicStep::class );

Queuety::workflow( 'brief_research' )
    ->then( PlanTopicsStep::class )
    ->start_agents( 'agent_tasks', $agent_run, group_key: 'researchers' )
    ->wait_for_agent_group( 'researchers', WaitMode::Quorum, 2 )
    ->then( SynthesizeBriefStep::class )
    ->dispatch( [ 'brief_id' => 42 ] );