n8n-io/n8n

Bug Description

On self-hosted instances with a large usable-credentials set (~2k), opening the Node Details View (NDV) for credential-using nodes (e.g. OpenAI Chat Model) freezes the UI for many seconds (observed ~5–22s).

Chrome Performance profiling shows the cost is almost entirely frontend main-thread work inside useNodeCredentialOptions during the dblclick handler — not network, database, or workflow size.

Hot path:

1. getCredentialOptions builds dropdown options with {...option} over Vue reactive usable credentials, which tracks every field.
2. isCredentialExisting rebuilds that full options list just to check one credential id.

This scales with instance usable-credentials size. A smaller instance on the same build (~600 credentials) does not show the lag. Reproduced on a brand-new empty workflow with only a newly added OpenAI Chat Model node.

Proposed fix

PR: https://github.com/n8n-io/n8n/pull/40198

• Spread toRaw(option) when building options
• O(1) usableCredentials map lookup for existence checks
• Keep overrideCredentials path for Instance AI

Validation

After applying the fix on a large self-hosted instance: NDV open dropped from ~ to ~ in Chrome Performance traces.