INVALID_PROMPT_INPUT
A prompt template received missing or invalid input variables.
Troubleshooting
The following may help resolve this error:
- Double-check your prompt template to ensure that it is correct.
- If you are using the default f-string format and you are using curly braces {anywhere in your template, they should be double escaped like this:{{(and if you want to render a double curly brace, you should use four curly braces:{{{{).
 
- If you are using the default f-string format and you are using curly braces 
- If you are using a MessagesPlaceholder, make sure that you are passing in an array of messages or message-like objects.- If you are using shorthand tuples to declare your prompt template, make sure that the variable name is wrapped in curly braces (["placeholder", "{messages}"]).
 
- If you are using shorthand tuples to declare your prompt template, make sure that the variable name is wrapped in curly braces (
- Try viewing the inputs into your prompt template using LangSmith or log statements to confirm they appear as expected.
- If you are pulling a prompt from the LangChain Prompt Hub, try pulling and logging it or running it in isolation with a sample input to confirm that it is what you expect.