FlowiseAI/Flowise · error · Error

Invalid base URL: must be a valid URL

Error message

Invalid base URL: must be a valid URL

What it means

The base URL must pass isValidURL, a security-hardened check: protocol must be http or https; hash fragments are rejected (they are an interpolation-exploit entry point); and the characters double-quote, single-quote, backtick, backslash, newline, carriage-return, and tab are rejected because the URL is later interpolated into JS. An empty, non-http, or fragment-bearing URL fails at init.

Source

Thrown at packages/components/nodes/sequentialagents/ExecuteFlow/ExecuteFlow.ts:180

            typeof nodeData.inputs?.overrideConfig === 'string' &&
            nodeData.inputs.overrideConfig.startsWith('{') &&
            nodeData.inputs.overrideConfig.endsWith('}')
                ? JSON.parse(nodeData.inputs.overrideConfig)
                : nodeData.inputs?.overrideConfig

        if (!sequentialNodes || !sequentialNodes.length) throw new Error('Execute Flow must have a predecessor!')

        const baseURL = (nodeData.inputs?.baseURL as string) || (options.baseURL as string)
        const returnValueAs = nodeData.inputs?.returnValueAs as string

        // Validate selectedFlowId is a valid UUID
        if (!selectedFlowId || !isValidUUID(selectedFlowId)) {
            throw new Error('Invalid flow ID: must be a valid UUID')
        }

        // Validate baseURL is a valid URL
        if (!baseURL || !isValidURL(baseURL)) {
            throw new Error('Invalid base URL: must be a valid URL')
        }

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

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

        let headers = {}
        if (chatflowApiKey) headers = { Authorization: `Bearer ${chatflowApiKey}` }

        const chatflowId = options.chatflowid
        const sessionId = options.sessionId
        const chatId = options.chatId

        const executeFunc = async (state: ISeqAgentsState) => {
            const variables = await getVars(appDataSource, databaseEntities, nodeData, options)

            let flowInput = ''

View on GitHub (pinned to abe4a8601a)

Solutions

1. Provide a full URL with scheme, e.g. http://localhost:3000 or https://flowise.example.com.
2. Strip any '#fragment' from the URL.
3. Remove any quotes, backslashes, or template-literal characters.
4. If relying on the server default, ensure options.baseURL is configured on the Flowise instance.

Example fix

// before (throws: no scheme, has fragment)
localhost:3000/api/v1/prediction/#main

// after
http://localhost:3000/api/v1/prediction/main

import { isValidURL } from '../../../src/validator'
const baseURL = (nodeData.inputs?.baseURL as string) || (options.baseURL as string)
if (!baseURL || !isValidURL(baseURL)) throw new Error('baseURL must be an http(s) URL with no fragment or escape chars')

const isSafeHttpUrl = (u: string): boolean => {
  try {
    const p = new URL(u)
    return (p.protocol === 'http:' || p.protocol === 'https:') && !p.hash && !/["'`\\\n\r\t]/.test(u)
  } catch { return false }
}

When it happens

Trigger: baseURL is empty (and options.baseURL is also unset); a scheme-less host like 'localhost:3000'; a URL containing a '#fragment'; a URL containing a quote or backslash from copy-paste; a non-http protocol (ftp:, file:).

Common situations: Running behind a reverse proxy and typing 'localhost:3000' without a scheme; leaving baseURL empty expecting a default that is not configured in options.baseURL; appending an anchor to the URL; copy-paste introducing stray quotes.

Related errors

• Execute Flow node name is required!
• Execute Flow must have a predecessor!
• Invalid flow ID: must be a valid UUID
• Cannot call the same agentflow!
• Invalid JSON in executeFlowOverrideConfig: ${parseError.mess

AI-assisted analysis of FlowiseAI/Flowise@abe4a8601a (2026-08-12). Data as JSON: /api/errors/ba96d0c2132a0d67. Report an issue: GitHub.