Merge

Overview

The merge node collects outputs from multiple upstream branches and combines them into a single JSON envelope, making them available as one value to downstream nodes. Use it whenever a workflow splits into parallel branches (e.g. two parallel lens nodes or battle_execute + vote_collector) and the results must be reunited before a downstream step. The merge behavior is controlled by the mode field: combine deep-merges objects by key, zip pairs array items by index, append concatenates arrays, and outer_join matches records on a shared key field. No credentials are required; the node operates purely on in-memory execution state.

Configuration

Field	Type	Required	Description
mode	enum	Yes	How the multiple upstream inputs are combined. combine merges objects by key (last writer wins on key collisions). zip pairs items positionally — output length equals the shorter input. append concatenates arrays in arrival order. outer_join matches records across inputs using the value of mergeKey.
mergeKey	string	No	The field name used to match records when mode is outer_join (e.g. id or email). Ignored for all other modes. Referencing a key that exists in only one input produces empty matches rather than an error.
strategy	enum	No	Edge-level override for how multiple values arriving on the same parameter label are resolved before the node-level mode is applied. Options: last_write_wins (default), concat (newline-joined), array (JS array), json_object (keyed by source node ID). When omitted, the run-level default last_write_wins applies.

Inputs

Port	Type	Description
input_a	any	First upstream branch. Accepts any IO type — text, json, array, object, battle_result, lens_result, etc.
input_b	any	Second upstream branch. Additional input ports are created automatically for each incoming edge — there is no fixed upper limit.
input_n	any	Nth upstream branch. Every inbound edge wires into the merge evaluation; the node waits for all connected upstream nodes to complete before executing.

Outputs

Port	Type	Description
merged	array	The combined result set produced by the selected merge mode. Downstream nodes typically reference $.merged to access the unified payload.
output	json	Full output envelope containing the merged value alongside standard execution metadata. Use this port when the downstream node expects a plain JSON object rather than an array.

Example

{
  "nodeType": "merge",
  "config": {
    "mode": "combine",
    "strategy": "json_object"
  }
}