> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/integrations/builtin/cluster-nodes/sub-nodes/n8n-nodes-langchain.modelselector.md).

# Use Model Selector in Duaer

Model Selector in Duaer is an AI or cluster node, often used with model, tool, or vector-store sub-nodes. Node note: Use this node to select one of the connected models to this node based on workflow data
## Model Selector in Duaer

Model Selector is used in Duaer’s AI or cluster features, often wired with chat-model, tool, or vector-store sub-nodes.

The product’s node note is: Use this node to select one of the connected models to this node based on workflow data.

## Credentials and parameters

Create the credential type this service needs under Credentials.

Parameters accept expressions. Tool parameters that an AI Agent should fill use $fromAI. When a run fails, read the error on the node output first.
## Questions

### How do you add Model Selector to a Duaer digital organization?

Open the node panel on the Duaer canvas, search for Model Selector, and drop it onto the digital organization. Connect it after a trigger or a previous node. If auth is required, save the credential first and select it on the node.

### What should you check first when Model Selector fails in Duaer?

Read the error text on that node’s output, then confirm the credential still works and required parameters are filled. For app nodes, also check permissions and quota on the provider side.