FlowiseAI/Flowise · error · Error

Invalid JSON in executeFlowOverrideConfig: ${parseError.mess

Error message

Invalid JSON in executeFlowOverrideConfig: ${parseError.message}

What it means

ExecuteFlow.run treats executeFlowOverrideConfig as a JSON object string only when it starts with '{' and ends with '}'; it then calls parseJsonBody. If parsing fails, it throws 'Invalid JSON in executeFlowOverrideConfig: <SyntaxError message>'. The error is raised before the outbound prediction call, so no request is sent.

Source

Thrown at packages/components/nodes/agentflow/ExecuteFlow/ExecuteFlow.ts:174

            const startAgentflowNode = previousNodes.find((node) => node.name === 'startAgentflow')
            const state = startAgentflowNode?.inputs?.startState as ICommonObject[]
            return state.map((item) => ({ label: item.key, name: item.key }))
        }
    }

    async run(nodeData: INodeData, _: string, options: ICommonObject): Promise<any> {
        const baseURL = (nodeData.inputs?.executeFlowBaseURL as string) || (options.baseURL as string)
        const selectedFlowId = nodeData.inputs?.executeFlowSelectedFlow as string
        const flowInput = nodeData.inputs?.executeFlowInput as string
        const returnResponseAs = nodeData.inputs?.executeFlowReturnResponseAs as string
        const _executeFlowUpdateState = nodeData.inputs?.executeFlowUpdateState

        let overrideConfig = nodeData.inputs?.executeFlowOverrideConfig
        if (typeof overrideConfig === 'string' && overrideConfig.startsWith('{') && overrideConfig.endsWith('}')) {
            try {
                overrideConfig = parseJsonBody(overrideConfig)
            } catch (parseError) {
                throw new Error(`Invalid JSON in executeFlowOverrideConfig: ${parseError.message}`)
            }
        }

        const state = options.agentflowRuntime?.state as ICommonObject
        const runtimeChatHistory = (options.agentflowRuntime?.chatHistory as BaseMessageLike[]) ?? []
        const isLastNode = options.isLastNode as boolean
        const sseStreamer: IServerSideEventStreamer | undefined = options.sseStreamer

        try {
            const credentialData = await getCredentialData(nodeData.credential ?? '', options)
            const chatflowApiKey = getCredentialParam('chatflowApiKey', credentialData, nodeData)

            if (!baseURL || !isValidURL(baseURL)) throw new Error('Invalid base URL: must be a valid URL')

            if (selectedFlowId === options.chatflowid) throw new Error('Cannot call the same agentflow!')

            let headers: Record<string, string> = {
                'Content-Type': 'application/json',

View on GitHub (pinned to abe4a8601a)

Solutions

1. Paste the override config through a JSON validator/linter and fix reported syntax errors.
2. Use double quotes for all keys and string values, remove trailing commas.
3. If using template variables, ensure they resolve to valid JSON-compatible values before the node runs.
4. Prefer passing overrideConfig as a real object rather than a string when the caller supports it.

Example fix

// before
executeFlowOverrideConfig = "{ sessionId: 'abc', }" // unquoted key + trailing comma

// after
executeFlowOverrideConfig = '{"sessionId":"abc"}'

function parseOverrideConfig(raw) {
  if (typeof raw === 'string' && raw.startsWith('{') && raw.endsWith('}')) {
    try { return JSON.parse(raw) }
    catch (e) { throw new Error('executeFlowOverrideConfig is not valid JSON: ' + e.message) }
  }
  return raw
}
overrideConfig = parseOverrideConfig(nodeData.inputs?.executeFlowOverrideConfig)

function isJsonObjectString(s) {
  return typeof s === 'string' && s.trim().startsWith('{') && s.trim().endsWith('}')
}

try { await executeFlow.run(nodeData, '', options) }
catch (e) {
  if (/Invalid JSON in executeFlowOverrideConfig/.test(e.message)) {
    // prompt user to fix the JSON in the node, then retry
  } else throw e
}

When it happens

Trigger: executeFlowOverrideConfig set to a string that looks like a JSON object (brace-wrapped) but has syntax errors: trailing comma, unquoted keys, single quotes, unescaped newlines, or a copy-paste with smart quotes.

Common situations: Operator hand-typing override config in the node; UI text field accepting malformed JSON; template variable left unresolved inside the JSON (e.g. {{var}} breaking syntax); mixed tab/space or BOM characters from a paste.

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 base URL: must be a valid URL
• Cannot call the same agentflow!
• Invalid JSON in the Additional Configuration:
• chatflowId must be a valid array
• Model is required

AI-assisted analysis of FlowiseAI/Flowise@abe4a8601a (2026-08-12). Data as JSON: /api/errors/246fbb2bec9ecad4. Report an issue: GitHub.