> ## Documentation Index
> Fetch the complete documentation index at: https://docs.comfy.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Node ID Migration for Frontend Extensions

> Migrate ComfyUI frontend extensions to branded string node IDs and the string subgraph boundary sentinels SUBGRAPH_INPUT_ID and SUBGRAPH_OUTPUT_ID.

ComfyUI frontend now normalizes local node IDs to the branded `NodeId` string
type at internal boundaries. Serialized workflows and API payloads may still
contain numeric IDs, but node IDs in litegraph, such as `node.id`,
`LLink.origin_id` and `LLink.target_id`, should be treated as strings after
they enter the frontend. Link IDs (`LLink.id`) and reroute IDs remain numbers.

Extension authors should avoid numeric comparisons against node IDs. In
particular, subgraph boundary sentinels are exposed as branded string IDs:

* `SUBGRAPH_INPUT_ID` serializes from `-10`
* `SUBGRAPH_OUTPUT_ID` serializes from `-20`

Compare against the strings `'-10'` and `'-20'`, or normalize both sides to
strings before comparing legacy values.


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