Merge Node

Combine data from multiple workflow branches into a single context. Supports five merge strategies — from simple object combination to inner joins and cartesian products.

How It Works

The Merge node accepts 2–10 input branches and waits for all of them to complete before merging their data. Choose a strategy that fits your use case.

Merge Strategies

Combine

Merge all branch contexts into a single object. Keys from later branches overwrite keys from earlier branches on collision.

textExample

Branch A: Shiprocket — Track Shipment → { shiprocket: { current_status: "In Transit" } }
Branch B: Razorpay — Fetch Payment   → { razorpay: { status: "captured", amount: 50000 } }

Merge (Combine)
→ Output: { shiprocket: {...}, razorpay: {...} }
→ Gmail — Send Email
    body: "Payment: {{razorpay.status}} | Shipping: {{shiprocket.current_status}}"

Position

Zip arrays from two branches by index. Pairs item[0] from branch A with item[0] from branch B, and so on.

Name	Type	Required	Default	Description
`fillMode`	`string`	No	`shortest`	"shortest" — stop at end of shortest array \| "longest" — pad with null

Cross Join

Create the cartesian product of two arrays — every item from branch A paired with every item from branch B (N × M output rows).

textExample — pair each product with each warehouse

Branch A: [ { sku: "TS-S" }, { sku: "TS-M" }, { sku: "TS-L" } ]
Branch B: [ { warehouse: "Mumbai" }, { warehouse: "Delhi" } ]

Merge (Cross Join) → 6 pairs:
  { sku: "TS-S", warehouse: "Mumbai" }
  { sku: "TS-S", warehouse: "Delhi" }
  { sku: "TS-M", warehouse: "Mumbai" }
  ...

Key Match (Inner Join)

Join two arrays where a shared key value matches — like a SQL inner join. Items without a matching key are excluded.

Name	Type	Required	Default	Description
`keyPath1`	`string`	Yes	—	Dot-path key in branch 1 array, e.g. orderId
`keyPath2`	`string`	Yes	—	Dot-path key in branch 2 array, e.g. order_id

Key Difference

Return only items from branch 1 that do NOT have a matching key in branch 2 — like a SQL LEFT ANTI JOIN. Use to find orders that have not been shipped.

Output Variables

Variable	Type	Description
`{{merge.result}}`	array \| object	The merged output — object for Combine, array for all others
`{{merge.count}}`	number	Number of items in result (array strategies)
`{{merge.mode}}`	string	The strategy used: combine \| position \| crossjoin \| keymatch \| keydiff
`{{merge.mergedAt}}`	string	ISO timestamp when merge completed

Complete Workflow Examples

Parallel Data Fetch + Combine

Use case: Fetch payment details and shipping status in parallel, then send a combined status email.

textWorkflow

Webhook Trigger (GET /order-status?orderId=...)
├─ Branch A → Razorpay — Fetch Payment
│              paymentId: {{body.paymentId}}
└─ Branch B → Shiprocket — Track Shipment
               awbCode: {{body.awb}}

→ Merge (Combine)
→ Gmail — Send Email
    to:   {{body.email}}
    body: "Payment: {{razorpay.status}}
           Shipping: {{shiprocket.current_status}}
           ETA: {{shiprocket.tracking_data.etd}}"

Find Unshipped Orders (Key Difference)

Use case: Find all paid orders that don't have a Shiprocket order yet.