13 Primitive Nodes

Workflows are composed from 13 node types. Each node declares a type, an id, a depends_on edge list, and a config block validated against a JSON Schema.

Control nodes

Node	Key config	Behavior
Sequential	(structural)	Wiring node for ordered chains
Parallel	join (all / any / first_n), n	Fan-out then join
Loop	max_iterations (1-1000), condition, body	Iterate a sub-graph
Branch	cases (map), default	Route by expression
HITL	actions (approve / edit / reject / reroute), timeout_seconds	Pause for a human

Leaf nodes

Node	Key config	Behavior
LLM	template or prompt, model, role	Call a model
Tool	tool (server.tool), args	Call an MCP tool
Research	query, depth (quick / standard / deep), max_sources	Gather sources
Execution	task, sandbox (docker / firecracker / none), max_steps	Run an agent task

Dynamic and state nodes

Node	Key config	Behavior
Coordinator	sub_agents, planning_model, plan_hitl, max_iterations	Plan and delegate
Memory	action (read / write / update / delete / summarize), key	Manage memory
Subworkflow	ref, inputs, version, timeout_seconds	Call another workflow
Knowledge	store, query, top_k, rerank, min_score	Retrieve from a store

Example

nodes:
  - id: plan
    type: LLM
    config: { role: planner, template: "Draft a plan for {{input.goal}}" }
  - id: search
    type: Research
    depends_on: [plan]
    config: { query: "{{plan.output}}", depth: standard }
  - id: approve
    type: HITL
    depends_on: [search]
    config: { actions: [approve, reject], timeout_seconds: 3600 }

Every node also accepts condition, on_error, retry, timeout_seconds, sensitivity, and disabled.