n8n Community Contributors: SAP Integration via Custom Nodes & OpenAPI Specs

Project Overview

A mid-sized manufacturing company relied on a legacy SAP ERP system for core operations but struggled to integrate it with modern SaaS tools like Salesforce, Slack, and Zendesk. Manual data entry and siloed workflows led to inefficiencies, errors, and delayed decision-making. The company partnered with n8n community contributors to automate SAP integrations using n8n’s open-source workflow automation platform.

The goal was to create a low-code, scalable solution leveraging n8n’s extensibility—custom nodes and OpenAPI specifications—to bridge SAP with other systems while preserving data integrity and reducing reliance on proprietary middleware.

Challenges

1. Legacy System Limitations: SAP’s SOAP-based APIs and complex data structures made real-time integration difficult without costly middleware.
2. Custom Logic Requirements: The company needed tailored workflows (e.g., auto-creating support tickets in Zendesk for SAP inventory alerts).
3. Security Constraints: SAP’s on-premise deployment required secure authentication (OAuth2, SSL) and data masking for sensitive fields.
4. Community Collaboration: The project relied on open-source contributors, requiring clear documentation and modular design for maintainability.

Solution

The team implemented a three-phase approach:

Phase 1: OpenAPI Specification for SAP

• Reverse-engineered SAP’s SOAP APIs into OpenAPI 3.0 specs using tools like SoapUI and swagger-codegen.
• Defined reusable schemas for SAP entities (e.g., purchase orders, inventory levels) to standardize data mapping.

Phase 2: Custom n8n Nodes

• Developed custom n8n nodes for SAP operations (e.g., SAP_GetMaterialDetails, SAP_TriggerBOMUpdate) using TypeScript.
• Added OAuth2 support for SAP’s authentication layer, with token refresh workflows.

Phase 3: Hybrid Workflow Design

• Built n8n workflows combining SAP custom nodes with existing app nodes (e.g., Salesforce, Slack). Example:
• Trigger: SAP low-stock alert → Action: Post to Slack channel + create Zendesk ticket with enriched CRM data.
• Deployed n8n on-premise alongside SAP for low-latency access, with failover to cloud backups.

Tech Stack

| Component | Tools/Technologies Used |
|-------------------------|-----------------------------------|
| Workflow Automation | n8n (self-hosted) |
| SAP Integration | Custom nodes, OpenAPI 3.0, SOAP |
| Security | OAuth2, TLS 1.3, Vault for secrets|
| Monitoring | Prometheus, Grafana |
| Collaboration | GitHub, n8n community forums |

Results

• 80% Reduction in Manual Effort: Automated 15+ workflows, including order processing and inventory syncs.
• Faster Response Times: SAP-to-Slack alerts reduced from 30 minutes to <10 seconds.
• Cost Savings: Avoided $200K+ in middleware licensing fees by using open-source tools.
• Community Impact: 3 custom nodes contributed to n8n’s public repository, reused by 50+ projects.

Key Takeaways

1. OpenAPI as a Bridge: Converting legacy APIs to OpenAPI specs future-proofs integrations for other tools.
2. Modular Design Pays Off: Building small, reusable custom nodes accelerated later workflow development.
3. Community-Driven Scalability: Public contributions reduced maintenance overhead and improved solution robustness.
4. Hybrid Deployment Matters: On-premise n8n instances ensured compliance without sacrificing cloud flexibility for non-SAP apps.

This project demonstrated how open-source automation tools like n8n—combined with community expertise—can modernize legacy systems without costly rip-and-replace approaches.