feat: Add ZenMux Chat Model node

[888-wzk]

Summary

ZenMux is the world’s first enterprise-grade large model aggregation platform with an insurance payout mechanism. The platform provides one-stop access to the latest models across providers.

Added support for new LLM provider:

• ZenMux Chat Model

Related Linear tickets, Github issues, and Community forum posts

Review / Merge checklist

• PR title and summary are descriptive. (conventions)
• Docs updated or follow-up ticket created.
• Tests included.
• PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

[CLAassistant]

All committers have signed the CLA.

[n8n-assistant]

Hey @888-wzk,

Thank you for your contribution. We appreciate the time and effort you’ve taken to submit this pull request.

Before we can proceed, please ensure the following:
• Tests are included for any new functionality, logic changes or bug fixes.
• The PR aligns with our contribution guidelines.

Regarding new nodes:
We no longer accept new nodes directly into the core codebase. Instead, we encourage contributors to follow our Community Node Submission Guide to publish nodes independently.

If your node integrates with an AI service that you own or represent, please email [email protected] and we will be happy to discuss the best approach.

About review timelines:
This PR has been added to our internal tracker as "GHC-6173". While we plan to review it, we are currently unable to provide an exact timeframe. Our goal is to begin reviews within a month, but this may change depending on team priorities. We will reach out when the review begins.

Thank you again for contributing to n8n.

[cubic-dev-ai]

2 issues found across 6 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="packages/@n8n/nodes-langchain/nodes/llms/LmChatZenMux/LmChatZenMux.node.ts">

<violation number="1" location="packages/@n8n/nodes-langchain/nodes/llms/LmChatZenMux/LmChatZenMux.node.ts:215">
P2: Rule violated: **Prefer Typeguards over Type casting**

Using `as string` for type narrowing violates the type safety rule. Consider using a type annotation with a type guard, or if `getNodeParameter` supports generics, use the generic parameter instead. While this pattern exists elsewhere in the codebase, the rule explicitly prohibits type narrowing with `as`.</violation>

<violation number="2" location="packages/@n8n/nodes-langchain/nodes/llms/LmChatZenMux/LmChatZenMux.node.ts:217">
P2: Rule violated: **Prefer Typeguards over Type casting**

Using `as { ... }` for type narrowing violates the type safety rule. Consider defining a proper interface for the options type and using a type guard function to validate the shape at runtime, or use a type annotation if the return type is compatible.</violation>
</file>

---

Since this is your first cubic review, here's how it works:

• cubic automatically reviews your code and comments on bugs and improvements
• Teach cubic by replying to its comments. cubic learns from your replies and gets better over time
• Ask questions if you need clarification on any suggestion

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}