feat: Add passThrough to preserve fields across nodes

[jimmylegendary]

Summary

This PR adds a new "Passthrough previous node output" feature that allows nodes to automatically include specified fields from previous node outputs in their own outputs. This enables preserving important data throughout a workflow without requiring manual configuration at each step.

The feature works by adding a text field in node settings where users can provide a comma-separated list of field names to be preserved. These fields are then automatically copied from the previous node's output to the current node's output, ensuring data continuity across the workflow.

Related Linear tickets, Github issues, and Community forum posts

Review / Merge checklist

Implementation details

• Added passThrough property to node interfaces
• Implemented passThrough field processing in the workflow execution engine
• Added UI settings field for configuring passThrough fields
• Supports dot notation for nested properties (e.g., "user.name")
• Works with all executable nodes in workflows

Testing

The feature can be tested by:

• Adding fields in a node (as shown in the screenshot)
• Setting up subsequent nodes with passThrough fields listed
• Running the workflow and confirming that specified fields persist through the node chain

[Mineru98]

LGTM👍👍👍

[Joffcom]

Hey @jimmylegendary,

Thanks for the PR, We have created "GHC-1544" as the internal reference to get this reviewed.

One of us will be in touch if there are any changes needed, in most cases this is normally within a couple of weeks but it depends on the current workload of the team.

[nestezup]

Looks super convenient!! 😊👍

[jeongkpa]

LGTM

[2innnnn0]

Looks Good To Me. Thanks Jimmy 👍

[craSH]

This is really nice! The word choice of the feature "bypass" is a bit confusing though, as a Reddit commenter suggested, could we consider using the term "Passthrough"?

https://www.reddit.com/r/n8n/comments/1jxfuqu/comment/mmqa5pn/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

[jimmylegendary]

This is really nice! The word choice of the feature "bypass" is a bit confusing though, as a Reddit commenter suggested, could we consider using the term "Passthrough"?

https://www.reddit.com/r/n8n/comments/1jxfuqu/comment/mmqa5pn/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Thank you. I changed the name