Why is the Output Parser returning empty?

[abhaysalvi]

The problem

Output parser connected to my LangChain node behaves so randomly. It sometimes doesn’t give the output at all!

What is the error message (if any)?

No errors at all. Just no output.

Please share your workflow

Share the output returned by the last node

{
  "action": 
    "parse",
    "response": 
    {
    }
}

Screenshot:

Information on your n8n setup

• n8n version: 1.101.1
• Database: PostgreSQL
• n8n EXECUTIONS_PROCESS setting (default: own, main): I don’t know
• Running n8n via: n8n cloud Pro

[Jim_Le]

Hey @abhaysalvi

Quick answer is your output parser schema definition should only include valid OpenAPI schema.

1. Using Define by Schema, just keep the “Output” definition and remove the rest
2. n8n also allows you to define using a json example. This way if you are unfamiliar with OpenAPI schema definitions, n8n can generate them for you.

Try both and see which you like.