🔬 Create & validate digital certificates with PDF Generator API and Gmail

⚡ 254 views · 🔬 Document Extraction & Analysis

Description

Quick overview

Issue and verify digital certificates with n8n using reusable PDF Generator API templates, unique certificate IDs, an n8n Data Table registry, Gmail delivery, and a public verification endpoint.

How it works

1. Certificate creation — A POST webhook receives the candidate’s name, surname, course, and email address.
2. Unique ID validation — The workflow generates a Certification ID and checks the Data Table to prevent identifier collisions.
3. Registry storage — Issued certificate records are persisted in an n8n Data Table for later lookup and verification.
4. Template-based PDF generation — PDF Generator API receives JSON containing candidate, course, date, and ID values mapped to placeholders in a reusable visual template.
5. Email delivery — Gmail sends the generated certificate PDF to the recipient supplied in the creation request.
6. Public verification — The verification endpoint searches the registry by Certification ID and returns whether the certificate is valid and who it belongs to.

Setup

1. Import the workflow — Import the included workflow JSON into n8n.
2. Create the Data Table — Add Name, Surname, and CertificationID fields and configure the insert and lookup nodes.
3. Import the PDF template — Import the provided PDF Generator API template and verify its placeholders match the JSON keys sent by the workflow.
4. Configure PDF Generator API — Add credentials and select the imported template in the PDF generation node.
5. Connect Gmail — Configure Gmail OAuth2 credentials for certificate delivery.
6. Test and activate — Create a sample certificate, confirm PDF mapping and email delivery, then test verification before activation.

Requirements

• n8n instance
• n8n Data Table with Name, Surname, and CertificationID
• PDF Generator API account and credentials
• Imported PDF Generator API certificate template
• Gmail OAuth2 credentials
• Publicly reachable webhooks when exposed externally
• Custom PDF Generator API template design (optional)
• QR code or additional visual elements (optional)
• Additional registry fields (optional)
• Frontend, LMS, or portal consuming the verification endpoint (optional)

Customization

• Template design — Change layout, fonts, colors, logos, signatures, QR codes, and other visual elements without embedding HTML in n8n.
• Template variables — Extend the JSON payload and matching placeholders with additional certificate information.
• Certificate ID — Replace the default ID-generation logic with another identifier format.
• Email delivery — Customize Gmail subject, body, attachment name, and recipient logic.
• Verification response — Extend the API response with additional non-sensitive certificate metadata.
• External integrations — Connect certificate creation to forms, an LMS, CRM, e-commerce flow, or another application.

Additional info

The reusable PDF template is included under PDFgeneratorAPI-Template/. Keep template placeholder names synchronized with the JSON keys sent by the workflow. Review webhook exposure, personal-data handling, authentication, and abuse prevention before production use.

🔗 Nodes Used

Webhook, Gmail, Data table

📥 Import

Download workflow.json and import into n8n: Workflow menu → Import from File

📖 Importing guide · 🔑 Credential setup