n8n-nodes-ldxhub

✅ Free to try — 25,000 credits/month, no credit card required
✅ One key for everything — OpenAI, Anthropic, Google, AWS, Azure, xAI
✅ 30-second sign-up — GitHub, Google, or email; your API key is shown immediately

n8n community node for LDX hub — AI-powered document processing platform: structured data extraction (StructFlow), XLIFF translation refinement (RefineLoop), layout-preserving OCR (RenderOCR), text-based PDF conversion (CastDoc), and plain-text/JSONL extraction (ExtractDoc).

Table of Contents

• Features
• Installation
• Prerequisites
• Credentials Setup
• Usage
  • StructFlow
  • RefineLoop
  • RenderOCR
  • CastDoc
  • ExtractDoc
• AI Agent Integration
• Polling Settings
• Troubleshooting
• Support
• Changelog
• License

Features

• StructFlow: Extract structured JSON from unstructured text using AI models (medical records, customer feedback, legal documents, and more)
• RefineLoop: Iteratively improve XLIFF translation quality using frontier AI models (Google Gemini, Anthropic Claude, OpenAI GPT, and more)
• RenderOCR: Convert PDFs and images to Word/Excel/PowerPoint with layout-preserving OCR (via industry-leading OCR engines)
• CastDoc: Convert text-based PDFs to Word/Excel/PowerPoint without OCR (high-fidelity layout preservation for digital-born documents)
• ExtractDoc: Extract plain text or JSONL from PDF/DOCX/XLSX/PPTX using the ki/extract engine (no AI, no OCR, free tier) — ideal as a preprocessing step before StructFlow
• One credential for all AI providers: OpenAI, Anthropic Claude, Google Gemini, AWS Nova, Azure OpenAI, xAI Grok — accessed through a single LDX hub API key
• HTTP long-polling architecture — compatible with n8n Cloud execution model
• Proven at scale: tested with 1.19M-character academic papers

Installation

In your n8n instance:

1. Go to Settings → Community Nodes
2. Click Install
3. Enter n8n-nodes-ldxhub and confirm

Prerequisites

• An LDX hub account
• n8n version supporting community nodes (v1.x or later)
• A paid or free tier subscription (free tier includes 25,000 credits/month, suitable for evaluation)

Credentials Setup

1. Sign up at the LDX hub DevPortal — free, no credit card. Use GitHub, Google, or email; your API key is shown immediately after sign-up.
2. Choose a subscription plan — start with Free (25,000 credits/month) to evaluate, or pick Starter / Standard / Pro for production. See pricing for details.
3. Click your account email in the top-right of the DevPortal, then select My Subscriptions
4. Under API Keys, copy the Current Key
5. In n8n, create a new LDXhub API credential:
   • Base URL: https://gw.ldxhub.io (default; leave as-is for production)
   • API Key: paste the key from step 4
6. Click Save — n8n will automatically test the credential by listing available models

If the credential test fails, verify:

• The API key is active (shown with a green dot in the DevPortal)
• The Base URL has no trailing slash
• Your network allows outbound HTTPS to gw.ldxhub.io

Usage

💡 Quick start: Import ready-to-use example workflows from examples/. Each example requires a LDXhub API credential and a placeholder input file path to be updated.

1. Add LDXhub API credentials (see Credentials Setup)
2. Add the LDXhub node to your workflow
3. Select a resource and operation (see below)

StructFlow — extract structured data from text

1. Resource: StructFlow → Operation: Run Extraction Job
2. Configure Model, System Prompt, and Example Output
3. Choose Input Mode:
   • Inline Inputs: Provide ID + Data pairs directly in the workflow (good for small batches, quick prototyping)
   • Binary File: Provide a JSONL file as binary input (good for large batches, or as part of an ExtractDoc → StructFlow pipeline)

Examples: Inline mode · Binary mode

RefineLoop — XLIFF translation refinement

1. Resource: RefineLoop → Operation: Run Refinement Job
2. Provide an XLIFF file via binary input
3. Choose an AI model and set max revisions

Example: RefineLoop workflow

RenderOCR — PDF/image to Office

1. Resource: RenderOCR → Operation: Run Conversion Job
2. Provide a PDF or image file via binary input
3. Choose an OCR engine, target language, and output format (docx/xlsx/pptx)

Example: RenderOCR workflow

CastDoc — text-based PDF to Office (no OCR)

1. Resource: CastDoc → Operation: Run Conversion Job
2. Provide a PDF file via binary input
3. Choose an engine and output format (docx/xlsx/pptx)

Example: CastDoc workflow

ExtractDoc — plain text or JSONL extraction (no AI, no OCR)

1. Resource: ExtractDoc → Operation: Run Conversion Job
2. Provide a PDF / DOCX / XLSX / PPTX file via binary input
3. Choose the ki/extract engine and output format (text or jsonl)

• Input: Binary file (PDF / DOCX / XLSX / PPTX)
• Output: Plain text (.txt) or JSONL (.jsonl)
• Use case: Preprocessing step before StructFlow (the Accordion pattern); also useful as a standalone free text extractor
• Pricing: Free tier (no AI, no OCR)
• Engine: ki/extract

AI Agent Integration

The LDXhub node is marked as usableAsTool: true, so it can be attached to an AI Agent node as a tool. This enables agentic workflows where an AI agent autonomously decides when to extract structured data, translate documents, or convert files using LDX hub.

Example use cases:

• Customer support agent that extracts structured complaint data from incoming emails (StructFlow)
• Document processing agent that automatically OCRs and translates uploaded PDFs (RenderOCR → RefineLoop)
• Knowledge base ingestion agent that converts and structures diverse document formats (CastDoc → StructFlow)

Polling Settings

For large documents, jobs may take several minutes. The node polls until completion:

| Setting | Default | Description | |---|---|---| | Max Polling Attempts | 180 | Maximum number of poll requests | | Server Wait Seconds | 10 | Server-side long-poll wait per request |

Theoretical max wait = Max Polling Attempts × Server Wait Seconds seconds. Defaults give 30 minutes. For longer documents, increase Max Polling Attempts (e.g., 360 for 60 minutes).

n8n Cloud users: your plan's workflow execution timeout applies independently. Check your plan's limits.

Troubleshooting

401 Unauthorized

• The API key is invalid, revoked, or expired
• Roll the key from My Subscriptions → API Keys → Roll API Key in the LDX hub DevPortal, then update the n8n credential

400 Bad Request — invalid file_id

• The binary input is missing or the binary field name is incorrect
• Check that the previous node outputs a binary property matching the Input Binary Field setting (default: data)

Job times out / polling exhausted

• Large documents may exceed the default 30-minute window
• Increase Max Polling Attempts in Polling Settings
• For n8n Cloud, also check your plan's workflow execution timeout

StructFlow Inline mode — empty results

• Ensure Inputs collection has at least one record with non-empty ID and Data fields
• Verify Example Output is valid JSON

Credit limit exceeded

• Your subscription's monthly credit allowance has been reached
• Check usage in the DevPortal's My Subscriptions page
• Upgrade your plan or wait for the next billing period

Support

• Product: https://ldxlab.io/ldxhub
• Documentation: https://gw.portal.ldxhub.io/introduction
• Bug reports & feature requests: GitHub Issues

Changelog

See CHANGELOG.md for the full version history.

License

MIT

Copyright (c) 2026 Kawamura International Co., Ltd.