How can I remove markdown formatting from my AI agent's JSON output?

I'm using an OpenAI chat model with an auto-fixing output parser that expects raw JSON. However, my agent is returning JSON wrapped in markdown syntax (i.e. json at the beginning and at the end), which causes errors in the parser.

For example, the output looks like this:

JSONCopied
{
 "keyword": "Siamese cat graphic tee",
 "status": "pass",
 "reason": "meets all criteria"
}

The parser has the following instructions:

Instructions:

{take in the input and return a pass or fail for the value of the object status. Provide a reason for passing or failing for the value of reason. }

Completion:

{completion}

Yet, the Completion did not satisfy these constraints and resulted in an error:

{error}

I need to configure either the AI agent or the post-processing step to output raw JSON without the markdown formatting. How can I achieve this?

Please also include your workflow, the output from the last node, and details about your n8n setup (n8n version, database type, n8n EXECUTIONS_PROCESS setting, environment, etc.).