start

Sole flow entry node — output only, at most one child

Graph entry point. Every flow must have exactly one start node. It has no input handle (output only) and may have at most one outgoing edge.

Run payload is not produced here. Chain start → input → … to put it on the wire, or use {{input.*}} in templates. Overview: How flows work.

Data

Input / output

Rules

• Exactly one start per flow
• No incoming edges
• At most one child (start → next only)
• All executable nodes must be reachable from start (note stickies are exempt and cannot be connected)
• Validation / run fails if these rules are broken

Examples

Minimal

{
  "id": "hello",
  "version": "v1",
  "nodes": [
    { "id": "start", "type": "start", "data": { "label": "Start" } },
    {
      "id": "out",
      "type": "output",
      "data": { "map": { "ok": "true" } }
    }
  ],
  "edges": [{ "id": "e0", "source": "start", "target": "out" }]
}

With input then HTTP

start → input → http → extract → output

{
  "edges": [
    { "id": "e0", "source": "start", "target": "input" },
    { "id": "e1", "source": "input", "target": "login" }
  ]
}

Not allowed: two starts, or start branching to two children.