Merge

Node type: merge · Version: 1 · Category: Logic Join named branches without arrival-time races. This node is not marked with the catalogue’s generic side-effect flag. That classification is not a guarantee that every configured operation is read-only; review the concrete action and its destination.

When to use this node

Converge named branches without depending on arrival timing.
Append, join, combine or deliberately choose among independent collections.

Example: Join rows by customer ID

Full-outer join two named inputs by explicit keys and nest conflicts by input.

Example settings

{
  "mode": "combine_fields",
  "inputPorts": [
    {
      "id": "input_a",
      "name": "Customers",
      "required": true
    },
    {
      "id": "input_b",
      "name": "Orders",
      "required": true
    }
  ],
  "join": "full",
  "leftKey": "id",
  "rightKey": "customerId",
  "conflictStrategy": "nest",
  "maxResults": 25000
}

This shows the important settings, not a complete exported node.

Connect each branch to its named input port.
Set both join keys and duplicate behavior.
Inspect empty inputs and expected result size before running.

Configuration

Field	Type	Default	What it controls
`mode`	string	`"wait_all"`	Wait, append, combine, join, multiply or choose named inputs. Values: `wait_all`, `append`, `combine_position`, `combine_fields`, `cartesian`, `choose_branch`.
`inputPorts`	array	`[{"id":"input_a","name":"Input A","required":true},{"id":"input_b","name":"Input B","required":true}]`	Stable ordered named input ports.
`unmatchedPolicy`	string	`"keep"`	Keep, drop or fail on unmatched positions. Values: `keep`, `drop`, `fail`.
`join`	string	`"inner"`	Inner, left, right or full outer field join. Values: `inner`, `left`, `right`, `full`.
`leftKey`	string	`"id"`	Join key path on the first input.
`rightKey`	string	`"id"`	Join key path on the second input.
`conflictStrategy`	string	`"nest"`	Nest, prefix, prefer one side or fail on property conflicts. Values: `nest`, `prefix`, `prefer_left`, `prefer_right`, `fail`.
`failedInputPolicy`	string	`"fail"`	Explicit failed-input behavior. Values: `fail`, `empty`.
`skippedInputPolicy`	string	`"empty"`	Explicit skipped-input behavior. Values: `fail`, `empty`.
`chooseStrategy`	string	`"first_non_empty"`	Choose the first non-empty or first successful input in priority order. Values: `first_non_empty`, `first_successful`.
`maxResults`	number	`25000`	Hard result bound, including Cartesian products.
`priority`	array	`["input_a","input_b"]`	Configured branch priority, independent of arrival time.

Workflow JSON

The editor stores this node with the following implemented default configuration:

Default node configuration

{
  "type": "merge",
  "version": 1,
  "configuration": {
    "mode": "wait_all",
    "inputPorts": [
      {
        "id": "input_a",
        "name": "Input A",
        "required": true
      },
      {
        "id": "input_b",
        "name": "Input B",
        "required": true
      }
    ],
    "unmatchedPolicy": "keep",
    "join": "inner",
    "leftKey": "id",
    "rightKey": "id",
    "conflictStrategy": "nest",
    "failedInputPolicy": "fail",
    "skippedInputPolicy": "empty",
    "chooseStrategy": "first_non_empty",
    "maxResults": 25000,
    "priority": [
      "input_a",
      "input_b"
    ]
  }
}

Values may be entered literally or mapped from an earlier compatible output when the inspector exposes a mapping control. See Variables and data mapping.

Inputs

Port	Type	Required	Description
`input_a`	`array`	Yes	Input A
`input_b`	`array`	Yes	Input B

Outputs

Port	Type	Required	Description
`output`	`array`	No	Merged

Execution behavior

Configured port order, never completion timing, determines append and priority order.
Cartesian results and every other result collection are hard bounded.
The editor catalogue declares output (array) for mapping. The execution inspector can contain additional evidence fields; inspect a real result before selecting nested paths from object or any outputs.

Common issues

Ordinary nodes cannot ambiguously converge; insert Merge.
Flat conflict strategies require object items; nesting is the safest general strategy.

Where it can run

Desktop local runner
Paired self-hosted runner
Hosted runner

Test and inspect

Use Test node in the editor to preview this step with the current configuration. A full run records resolved inputs, outputs, logs, duration, and any artifacts in the execution inspector. Side-effecting or destructive nodes can require an additional confirmation or approved workflow permission.

Node reference

Triggers

Logic

Data

Network

Browser

Communication

System

When to use this node

Example: Join rows by customer ID

Configuration

Workflow JSON

Inputs

Outputs

Execution behavior

Common issues

Where it can run

Test and inspect

​When to use this node

​Example: Join rows by customer ID

​Configuration

​Workflow JSON

​Inputs

​Outputs

​Execution behavior

​Common issues

​Where it can run

​Test and inspect

​Related guides

When to use this node

Example: Join rows by customer ID

Configuration

Workflow JSON

Inputs

Outputs

Execution behavior

Common issues

Where it can run

Test and inspect

Related guides