# Crosstech Impl N8n Aec Pipeline

> >

- **Type:** Skill
- **Install:** `agentstack add skill-impertio-studio-cross-tech-aec-claude-skill-package-crosstech-impl-n8n-aec-pipeline`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Impertio-Studio](https://agentstack.voostack.com/s/impertio-studio)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Impertio-Studio](https://github.com/Impertio-Studio)
- **Source:** https://github.com/Impertio-Studio/Cross-Tech-AEC-Claude-Skill-Package/tree/main/skills/source/crosstech-impl/crosstech-impl-n8n-aec-pipeline

## Install

```sh
agentstack add skill-impertio-studio-cross-tech-aec-claude-skill-package-crosstech-impl-n8n-aec-pipeline
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# crosstech-impl-n8n-aec-pipeline

## Quick Reference

### Core n8n Nodes for AEC Automation

| Node | Type Identifier | AEC Purpose |
|------|----------------|-------------|
| HTTP Request | `n8n-nodes-base.httpRequest` | Call ERPNext, Speckle, IfcPipeline REST APIs |
| Webhook | `n8n-nodes-base.webhook` | Receive IFC uploads, Speckle commit events |
| Code | `n8n-nodes-base.code` | Transform JSON data, format reports, light parsing |
| Execute Command | `n8n-nodes-base.executeCommand` | Run IfcOpenShell scripts, CLI tools on host |
| Schedule Trigger | `n8n-nodes-base.scheduleTrigger` | Nightly BIM checks, scheduled exports |
| FTP/SFTP | `n8n-nodes-base.ftp` | Upload/download IFC files from project servers |
| If | `n8n-nodes-base.if` | Route on validation pass/fail |
| Switch | `n8n-nodes-base.switch` | Route by IFC schema version or element type |
| Merge | `n8n-nodes-base.merge` | Combine data from multiple AEC sources |
| Execute Sub-workflow | `n8n-nodes-base.executeWorkflow` | Modular reusable pipeline stages |
| Send Email | `n8n-nodes-base.emailSend` | Distribute reports to project teams |

### Critical Warnings

**NEVER** run heavy IFC geometry processing inside n8n Code nodes — n8n runs JavaScript with a 10-second default timeout. ALWAYS delegate to external Python services via Execute Command or HTTP Request.

**NEVER** store IFC files in n8n's JSON data flow — binary files MUST be handled via file system paths or binary properties. n8n nodes pass JSON arrays between them; embedding multi-MB binary data causes memory exhaustion.

**NEVER** hardcode credentials in workflow JSON — ALWAYS use n8n's encrypted credential store. Workflow JSON is exportable and shareable; embedded secrets leak.

**ALWAYS** set explicit timeouts on Execute Command nodes running IfcOpenShell scripts — large IFC files (100MB+) can take minutes to process. The default timeout causes silent failures.

---

## Technology Boundary

### Side A: n8n Workflow Engine (v1.x)

| Aspect | Detail |
|--------|--------|
| Runtime | Node.js 18+ (self-hosted) or n8n Cloud |
| Data model | JSON arrays flowing between nodes |
| Execution | Sequential node execution with branching |
| Triggers | Webhook, Schedule, Manual, External event |
| Extensions | Community nodes via npm (`n8n-nodes-*`) |
| Binary handling | `$binary` object with `fileName`, `mimeType`, `data` |
| Credential storage | AES-256 encrypted in n8n database |
| Docker image | `n8nio/n8n:latest` (or pinned version tag) |

### Side B: AEC Tool APIs (Speckle, ERPNext, IfcOpenShell)

| Service | Protocol | Authentication | Data Format |
|---------|----------|---------------|-------------|
| ERPNext | REST (`/api/resource/:doctype`) | Token: `api_key:api_secret` | JSON |
| Speckle | GraphQL + REST | Bearer token (PAT) | JSON + binary streams |
| IfcOpenShell | CLI / Python scripts | N/A (local execution) | IFC (STEP), JSON output |
| IfcPipeline | REST (FastAPI) | API key header | JSON + binary IFC |
| QGIS Server | WMS/WFS (OGC) | None (internal network) | XML/GML |

### The Bridge: HTTP / Webhook / CLI Integration

n8n connects to AEC services through three integration patterns:

1. **HTTP Request nodes** → REST/GraphQL APIs (Speckle, ERPNext, IfcPipeline)
2. **Webhook nodes** → receive push events from Speckle commits, file uploads
3. **Execute Command nodes** → invoke IfcOpenShell Python scripts on the host

Data transformation happens in Code nodes (JavaScript) between these boundary crossings. The Code node transforms AEC-specific JSON structures into the format expected by the next service.

**Data loss at boundary:** IFC geometry is NEVER transmitted through n8n's JSON pipeline. Only metadata, quantities, and validation results cross the n8n boundary. Geometry stays in IFC files on disk or in dedicated services.

---

## Critical Rules

1. **ALWAYS** delegate IFC processing to external services — n8n is an orchestrator, not a compute engine
2. **ALWAYS** use `$binary` properties for file transfers — NEVER base64-encode IFC files into JSON fields
3. **ALWAYS** configure Error Trigger nodes (`n8n-nodes-base.errorTrigger`) for every production pipeline
4. **ALWAYS** use Execute Sub-workflow for reusable pipeline stages (validation, notification)
5. **NEVER** process IFC geometry in Code nodes — Code nodes run JavaScript with limited memory and timeout
6. **NEVER** expose webhook URLs without authentication in production — use header auth or webhook path secrets
7. **ALWAYS** set `continueOnFail: true` on non-critical nodes to prevent full pipeline abort
8. **ALWAYS** store AEC service credentials in n8n's credential store with the correct type

---

## Decision Tree

```
Need to automate an AEC workflow?
├── Trigger type?
│   ├── File upload event → Webhook node (POST, binary)
│   ├── Speckle model commit → Webhook node (Speckle webhook callback)
│   ├── Scheduled check → Schedule Trigger node (cron expression)
│   └── Manual/API trigger → Manual Trigger or Webhook node
├── Need IFC processing?
│   ├── Light metadata extraction → Execute Command (IfcOpenShell script)
│   ├── Heavy geometry operations → HTTP Request to IfcPipeline service
│   ├── Validation/clash detection → HTTP Request to IfcPipeline `/ifctester` or `/ifcclash`
│   └── Format conversion → HTTP Request to IfcPipeline `/ifcconvert`
├── Need to update external system?
│   ├── ERPNext BOM/Item → HTTP Request (POST /api/resource/:doctype)
│   ├── Speckle stream → HTTP Request (GraphQL mutation)
│   ├── Notification → Send Email or HTTP Request (Slack/Teams webhook)
│   └── File delivery → FTP/SFTP node
└── Error handling?
    ├── Validation failure → If node routes to notification branch
    ├── Service down → Error Trigger → retry or alert
    └── Partial failure → continueOnFail: true on non-critical nodes
```

---

## Essential Patterns

### Pattern 1: IFC Upload → Validation → Extraction → Report

**Flow:** Webhook → Execute Command (validate) → If → Execute Command (extract) → HTTP Request (ERPNext) → Send Email

```
[Webhook: IFC Upload] → [Execute Command: validate_ifc.py]
    → [If: valid?]
        ├── YES → [Execute Command: extract_quantities.py]
        │         → [Code: transform to ERPNext format]
        │         → [HTTP Request: POST /api/resource/BOM]
        │         → [Send Email: success report]
        └── NO  → [Send Email: validation failure report]
```

**Webhook node configuration:**
- Method: POST
- Path: `ifc-upload`
- Binary Property: `ifc_file`
- Options: `rawBody: true`

**Execute Command configuration:**
- Command: `python3 /scripts/validate_ifc.py --input /tmp/{{ $binary.ifc_file.fileName }}`
- ALWAYS use absolute paths to scripts
- ALWAYS pass file paths, not file content

### Pattern 2: Speckle Webhook → Change Detection → Notification

**Flow:** Webhook → HTTP Request (Speckle GraphQL) → Code (diff) → If → HTTP Request (notify)

```
[Webhook: Speckle commit] → [HTTP Request: fetch commit details]
    → [Code: compare with previous commit]
    → [If: significant changes?]
        ├── YES → [HTTP Request: Slack notification]
        └── NO  → [No operation]
```

**Speckle GraphQL query for commit details:**
```graphql
query {
  stream(id: "{{ $json.payload.streamId }}") {
    commit(id: "{{ $json.payload.commitId }}") {
      message
      authorName
      createdAt
      referencedObject
    }
  }
}
```

### Pattern 3: Scheduled BIM Quality Check → Report → Email

**Flow:** Schedule Trigger → Execute Command (quality check) → Code (format) → Send Email

```
[Schedule Trigger: 02:00 daily] → [Execute Command: bim_quality_check.py]
    → [Code: format HTML report]
    → [Send Email: distribute to project team]
```

**Schedule Trigger configuration:**
- Rule: `0 2 * * *` (daily at 02:00)
- Timezone: project-local timezone

---

## Common Operations

### Credential Configuration for AEC Services

| Service | n8n Credential Type | Header Name | Header Value |
|---------|-------------------|-------------|--------------|
| ERPNext | Header Auth | `Authorization` | `token {api_key}:{api_secret}` |
| Speckle | Header Auth | `Authorization` | `Bearer {personal_access_token}` |
| IfcPipeline | Header Auth | `X-API-Key` | `{api_key}` |

### HTTP Request to ERPNext API

```json
{
  "method": "POST",
  "url": "https://erp.example.com/api/resource/BOM",
  "authentication": "genericCredentialType",
  "genericAuthType": "httpHeaderAuth",
  "sendBody": true,
  "specifyBody": "json",
  "jsonBody": "={{ JSON.stringify({ data: { item: $json.item_code, items: $json.bom_items, quantity: 1 } }) }}"
}
```

### Execute Command for IfcOpenShell

```json
{
  "command": "python3 /scripts/extract_quantities.py --input \"{{ $json.file_path }}\" --format json",
  "timeout": 120000
}
```

**ALWAYS** set timeout to at least 120000ms (2 minutes) for IFC processing scripts. Large models require 5-10 minutes — set timeout accordingly.

### IfcPipeline Integration via HTTP Request

```json
{
  "method": "POST",
  "url": "http://ifcpipeline:8000/ifctester",
  "authentication": "genericCredentialType",
  "sendBody": true,
  "specifyBody": "json",
  "jsonBody": "={{ JSON.stringify({ ifc_file: $json.file_path, ids_file: '/specs/project.ids' }) }}"
}
```

**IfcPipeline endpoints:**

| Endpoint | Purpose | Input |
|----------|---------|-------|
| `/ifcconvert` | Convert IFC to GLB, OBJ, DAE | IFC file path + target format |
| `/ifccsv` | Export/import IFC data as CSV | IFC file path |
| `/ifcclash` | Geometric clash detection | Two IFC file paths |
| `/ifctester` | IDS validation | IFC file path + IDS file |
| `/ifcdiff` | Model version comparison | Two IFC file paths |
| `/calculate-qtos` | Quantity takeoff | IFC file path |
| `/ifc2json` | JSON export for viewers | IFC file path |

### Error Handling Pattern

ALWAYS add an Error Trigger workflow that catches failures from production pipelines:

```
[Error Trigger] → [Code: format error details]
    → [If: severity]
        ├── CRITICAL → [Send Email: ops team] + [HTTP Request: Slack alert]
        └── WARNING  → [Send Email: project lead]
```

Set `continueOnFail: true` on nodes where partial failure is acceptable (e.g., notification nodes).

### Sub-workflow Pattern for Reusable Stages

Extract common operations into sub-workflows called via Execute Sub-workflow node:

- **IFC Validation Sub-workflow**: Webhook input → validate → return pass/fail JSON
- **ERPNext BOM Creation Sub-workflow**: JSON input → create Items → create BOM → return BOM name
- **Notification Sub-workflow**: message + recipients → email + Slack

---

## n8n-nodes-ifcpipeline Community Node

The `n8n-nodes-ifcpipeline` package (install via n8n Community Nodes) provides dedicated nodes for IfcPipeline operations without manual HTTP configuration:

```bash
# Install in n8n (Settings → Community Nodes)
n8n-nodes-ifcpipeline
```

This replaces manual HTTP Request configuration for all `/ifc*` endpoints with visual node configuration.

---

## Reference Links

- [references/methods.md](references/methods.md) — n8n node reference, API endpoints, credential setup
- [references/examples.md](references/examples.md) — Complete workflow JSON snippets for AEC pipelines
- [references/anti-patterns.md](references/anti-patterns.md) — Common n8n AEC pipeline mistakes

### Official Sources

- https://docs.n8n.io/integrations/builtin/core-nodes/ — n8n core node reference
- https://docs.n8n.io/hosting/installation/server-setups/docker-compose/ — n8n Docker deployment
- https://docs.n8n.io/code/builtin/overview/ — n8n Code node reference
- https://speckle.guide/dev/server-webhooks.html — Speckle webhook documentation
- https://frappeframework.com/docs/user/en/api/rest — ERPNext/Frappe REST API
- https://github.com/jonatanjacobsson/ifcpipeline — IfcPipeline project
- https://github.com/jonatanjacobsson/n8n-nodes-ifcpipeline — n8n-nodes-ifcpipeline community node

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Impertio-Studio](https://github.com/Impertio-Studio)
- **Source:** [Impertio-Studio/Cross-Tech-AEC-Claude-Skill-Package](https://github.com/Impertio-Studio/Cross-Tech-AEC-Claude-Skill-Package)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-impertio-studio-cross-tech-aec-claude-skill-package-crosstech-impl-n8n-aec-pipeline
- Seller: https://agentstack.voostack.com/s/impertio-studio
- Browse the marketplace: https://agentstack.voostack.com/browse

---
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