{ "name": "FilePost — Send an expiring client preview with SendGrid", "nodes": [ { "parameters": { "content": "## Expiring preview delivery\n\nThis workflow turns a temporary source URL into a FilePost link that deletes itself, then emails the recipient through SendGrid. There is no long-running Wait node: FilePost enforces expiry at the storage layer.\n\n### Webhook fields\nRequired: `file_url`, `recipient_email`. Optional: `recipient_name`, `project_name`, `message`, `filename`, and `expires_in` (`1h`, `6h`, `24h`, `3d`, or `7d`).\n\n### Setup\n1. Install and connect `n8n-nodes-filepost`.\n2. On **Send Preview Email**, add Header Auth: `Authorization: Bearer YOUR_SENDGRID_API_KEY`.\n3. Set `SENDER_EMAIL` and optionally `SENDER_NAME` in n8n variables.\n\nFilePost URLs are public-by-link. Do not use this template for files that require identity-based access control.", "height": 590, "width": 640, "color": 5 }, "id": "bcaee702-fb5c-4985-95d7-75c3ea64fe08", "name": "Setup and security note", "type": "n8n-nodes-base.stickyNote", "typeVersion": 1, "position": [-840, -420] }, { "parameters": { "httpMethod": "POST", "path": "filepost-expiring-client-preview", "responseMode": "responseNode", "options": {} }, "id": "5f07eddb-f024-4d58-9aa2-d8c13669f6c1", "name": "Receive Preview Request", "type": "n8n-nodes-base.webhook", "typeVersion": 2, "position": [-800, 100], "webhookId": "filepost-expiring-preview-template" }, { "parameters": { "jsCode": "const body = $input.first().json.body || $input.first().json;\nif (!body.file_url) throw new Error('file_url is required');\nconst email = String(body.recipient_email || '').trim().toLowerCase();\nif (!/^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$/.test(email)) throw new Error('recipient_email is invalid');\nconst fileUrl = new URL(body.file_url);\nif (!['http:', 'https:'].includes(fileUrl.protocol)) throw new Error('file_url must use http or https');\nconst allowedExpiry = new Set(['1h', '6h', '24h', '3d', '7d']);\nconst expiresIn = allowedExpiry.has(String(body.expires_in || '')) ? String(body.expires_in) : '24h';\nconst clean = (value, fallback = '', max = 500) => String(value || fallback).trim().replace(/[\\r\\n]+/g, ' ').slice(0, max);\nconst filename = clean(body.filename || fileUrl.pathname.split('/').pop(), 'preview.bin', 180);\nreturn [{ json: {\n fileUrl: fileUrl.toString(),\n recipientEmail: email,\n recipientName: clean(body.recipient_name, 'there', 120),\n projectName: clean(body.project_name, 'Your preview', 180),\n message: clean(body.message, '', 1000),\n filename,\n expiresIn,\n requestedAt: new Date().toISOString()\n} }];" }, "id": "74010588-f0fd-4ae4-ae60-92b0d56bdf7e", "name": "Validate Preview Request", "type": "n8n-nodes-base.code", "typeVersion": 2, "position": [-560, 100] }, { "parameters": { "url": "={{ $json.fileUrl }}", "options": { "response": { "response": { "responseFormat": "file", "outputPropertyName": "data" } } } }, "id": "9227801d-4dd0-4a30-be42-452932de47bb", "name": "Download Preview File", "type": "n8n-nodes-base.httpRequest", "typeVersion": 4.2, "position": [-320, 100] }, { "parameters": { "operation": "upload", "binaryPropertyName": "data", "expiresIn": "={{ $('Validate Preview Request').first().json.expiresIn }}", "filenameMode": "public" }, "id": "398406fb-e068-443f-8040-1a7c2cefa22c", "name": "Create Expiring FilePost Link", "type": "n8n-nodes-filepost.filePost", "typeVersion": 1, "position": [-80, 100] }, { "parameters": { "jsCode": "const meta = $('Validate Preview Request').first().json;\nconst hosted = $input.first().json;\nconst escapeHtml = (value) => String(value).replace(/[&<>\"']/g, (char) => ({ '&': '&', '<': '<', '>': '>', '\"': '"', \"'\": ''' })[char]);\nconst expiryLabels = { '1h': 'one hour', '6h': 'six hours', '24h': '24 hours', '3d': 'three days', '7d': 'seven days' };\nconst senderEmail = String($vars.SENDER_EMAIL || '').trim();\nif (!senderEmail) throw new Error('Set the SENDER_EMAIL n8n variable before running this workflow');\nconst senderName = String($vars.SENDER_NAME || 'File delivery').trim();\nconst note = meta.message ? `

${escapeHtml(meta.message)}

` : '';\nconst html = `

${escapeHtml(meta.projectName)}

Hi ${escapeHtml(meta.recipientName)},

Your preview ${escapeHtml(meta.filename)} is ready.

${note}

Open preview

This public-by-link URL expires in ${expiryLabels[meta.expiresIn]}. Do not forward it.

`;\nconst text = `Hi ${meta.recipientName},\\n\\nYour preview ${meta.filename} is ready: ${hosted.url}\\n\\nThis public-by-link URL expires in ${expiryLabels[meta.expiresIn]}. Do not forward it.`;\nreturn [{ json: {\n sendgridBody: { personalizations: [{ to: [{ email: meta.recipientEmail }] }], from: { email: senderEmail, name: senderName }, subject: `${meta.projectName} — preview ready`, content: [{ type: 'text/plain', value: text }, { type: 'text/html', value: html }] },\n recipientEmail: meta.recipientEmail,\n projectName: meta.projectName,\n filename: meta.filename,\n expiresIn: meta.expiresIn,\n previewUrl: hosted.url,\n filepostFileId: hosted.file_id,\n expiresAt: hosted.expires_at\n} }];" }, "id": "c03cd8ac-3897-46b0-9650-ccf3be141ea6", "name": "Build Preview Email", "type": "n8n-nodes-base.code", "typeVersion": 2, "position": [160, 100] }, { "parameters": { "method": "POST", "url": "https://api.sendgrid.com/v3/mail/send", "authentication": "genericCredentialType", "genericAuthType": "httpHeaderAuth", "sendBody": true, "specifyBody": "json", "jsonBody": "={{ JSON.stringify($json.sendgridBody) }}", "options": {} }, "id": "fd13ae09-6bd5-4c46-96c5-56d604a33422", "name": "Send Preview Email", "type": "n8n-nodes-base.httpRequest", "typeVersion": 4.2, "position": [400, 100] }, { "parameters": { "jsCode": "const delivery = $('Build Preview Email').first().json;\nreturn [{ json: {\n success: true,\n recipient_email: delivery.recipientEmail,\n project_name: delivery.projectName,\n filename: delivery.filename,\n preview_url: delivery.previewUrl,\n expires_in: delivery.expiresIn,\n expires_at: delivery.expiresAt,\n filepost_file_id: delivery.filepostFileId\n} }];" }, "id": "681c1706-d752-42c5-a939-1bc97c715c65", "name": "Build Delivery Result", "type": "n8n-nodes-base.code", "typeVersion": 2, "position": [640, 100] }, { "parameters": { "respondWith": "json", "responseBody": "={{ $json }}", "options": {"responseCode": 201} }, "id": "fa4ef8db-ad94-4fe6-9450-5dc5c1ac0739", "name": "Return Delivery Result", "type": "n8n-nodes-base.respondToWebhook", "typeVersion": 1.4, "position": [880, 100] } ], "connections": { "Receive Preview Request": {"main": [[{"node": "Validate Preview Request", "type": "main", "index": 0}]]}, "Validate Preview Request": {"main": [[{"node": "Download Preview File", "type": "main", "index": 0}]]}, "Download Preview File": {"main": [[{"node": "Create Expiring FilePost Link", "type": "main", "index": 0}]]}, "Create Expiring FilePost Link": {"main": [[{"node": "Build Preview Email", "type": "main", "index": 0}]]}, "Build Preview Email": {"main": [[{"node": "Send Preview Email", "type": "main", "index": 0}]]}, "Send Preview Email": {"main": [[{"node": "Build Delivery Result", "type": "main", "index": 0}]]}, "Build Delivery Result": {"main": [[{"node": "Return Delivery Result", "type": "main", "index": 0}]]} }, "active": false, "settings": {"executionOrder": "v1"}, "versionId": "f383d126-cbf4-4f97-9a83-f98aa564e765", "meta": {"templateCredsSetupCompleted": false}, "tags": [] }