Working with multiple n8n instances over MCP

When the n8n_instances tool is available, the user has multi-instance mode on: one MCP connection can reach several n8n instances (e.g. prod, staging, or one per client/team). Every other n8n tool (n8n_get_workflow, n8n_list_workflows, n8n_update_partial_workflow, n8n_manage_datatable, n8n_manage_credentials, n8n_executions, n8n_test_workflow, …) runs against whichever instance this session is currently targeting. There is no per-call instance argument: you change the target only by switching. Target the wrong instance and a read returns the wrong data and a write lands in the wrong place — usually with no error (the one exception is an ambiguous credential write, which fails closed; see below). So target deliberately.

If the n8n_instances tool is not present, the account is single-instance: ignore this skill and use the n8n tools directly.

Golden rules

Six rules. Each prevents a class of silent misroute.