FlowiseAI/Flowise · error · Error

Invalid JSON in the OpenAI's BaseOptions:

Error message

Invalid JSON in the OpenAI's BaseOptions: 

What it means

OpenAI LLM node's baseOptions branch: JSON.parse runs only when baseOptions is not an object; a SyntaxError is caught and re-thrown with this prefix. Object inputs skip parsing.

Source

Thrown at packages/components/nodes/llms/OpenAI/OpenAI.ts:184

            streaming: streaming ?? true
        }

        if (maxTokens) obj.maxTokens = parseInt(maxTokens, 10)
        if (topP) obj.topP = parseFloat(topP)
        if (frequencyPenalty) obj.frequencyPenalty = parseFloat(frequencyPenalty)
        if (presencePenalty) obj.presencePenalty = parseFloat(presencePenalty)
        if (timeout) obj.timeout = parseInt(timeout, 10)
        if (batchSize) obj.batchSize = parseInt(batchSize, 10)
        if (bestOf) obj.bestOf = parseInt(bestOf, 10)

        if (cache) obj.cache = cache

        let parsedBaseOptions: any | undefined = undefined
        if (baseOptions) {
            try {
                parsedBaseOptions = typeof baseOptions === 'object' ? baseOptions : JSON.parse(baseOptions)
            } catch (exception) {
                throw new Error("Invalid JSON in the OpenAI's BaseOptions: " + exception)
            }
        }

        if (basePath || parsedBaseOptions) {
            obj.configuration = {
                baseURL: basePath,
                defaultHeaders: parsedBaseOptions
            }
        }

        const model = new OpenAI(obj)
        return model
    }
}

module.exports = { nodeClass: OpenAI_LLMs }

View on GitHub (pinned to abe4a8601a)

Solutions

1. Validate baseOptions as JSON in the UI before saving.
2. Pass baseOptions as an object to bypass the parse branch.
3. Lint the JSON (jq . <<< "$opts") to find the exact syntax error.

Example fix

// before
{ temperature: 0.7, top_p: 0.9, }
// after
{"temperature":0.7,"top_p":0.9}

function parseBaseOptions(raw: unknown): Record<string, unknown> | undefined {
  if (raw == null) return undefined
  if (typeof raw === 'object') return raw as Record<string, unknown>
  if (typeof raw === 'string') JSON.parse(raw)
  return undefined
}

function isJsonObjectString(v: string): v is string {
  try { const o = JSON.parse(v); return typeof o === 'object' && o !== null } catch { return false }
}

try {
  parsedBaseOptions = typeof baseOptions === 'object' ? baseOptions : JSON.parse(baseOptions)
} catch (e) {
  throw new Error(`BaseOptions is not valid JSON: ${(e as Error).message}`)
}

When it happens

Trigger: Free-form BaseOptions string in the OpenAI LLM node that is not valid JSON (trailing comma, single quotes, unquoted keys, stray characters).

Common situations: Pasting a JS object literal into the field; curly-quote corruption; stale config migrated from an object to a string representation.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Invalid JSON in the OpenAIEmbedding's BaseOptions:
• Invalid JSON in the ChatOpenAI's BaseOptions:
• Invalid JSON in the Chat NVIDIA NIM's baseOptions: ${excepti
• Invalid JSON in the ChatOpenAI's BaseOptions: ${exception}
• Invalid JSON in the Additional Configuration:

AI-assisted analysis of FlowiseAI/Flowise@abe4a8601a (2026-08-12). Data as JSON: /api/errors/8373ff192438e671. Report an issue: GitHub.