{"id":1156,"date":"2026-05-22T13:00:00","date_gmt":"2026-05-22T18:00:00","guid":{"rendered":"https:\/\/tolinku.com\/blog\/?p=1156"},"modified":"2026-03-07T03:34:58","modified_gmt":"2026-03-07T08:34:58","slug":"webhook-email-automation","status":"publish","type":"post","link":"https:\/\/tolinku.com\/blog\/webhook-email-automation\/","title":{"rendered":"Email Automation Triggered by Deep Link Webhooks"},"content":{"rendered":"\n

A user clicks your campaign link, installs the app, and creates an account. Three days later, they haven't opened the app again. If you had an automated email sequence triggered by the install event, that re-engagement email would already be in their inbox.<\/p>\n\n\n\n

Deep link webhooks turn passive link tracking into active marketing triggers. Instead of querying an analytics dashboard to find users who installed but didn't return, you let the events drive the workflow. This guide covers how to connect Tolinku webhooks<\/a> to email platforms (SendGrid, Mailchimp, and generic SMTP) for automated sequences. For the webhook setup, see the webhook setup guide<\/a>.<\/p>\n\n\n\n

\"Tolinku\nThe webhooks page with create form, webhook list, and delivery log.<\/em><\/p>\n\n\n\n

Which Events Trigger Emails?<\/h2>\n\n\n\n

Not every webhook event should send an email. Here's how each event type maps to email use cases:<\/p>\n\n\n\n

\n\n\n\n\n\n\n\n
Event<\/th>\nEmail Use Case<\/th>\nWho Receives It<\/th>\n<\/tr>\n<\/thead>\n
install.tracked<\/code><\/td>\nWelcome sequence, onboarding tips<\/td>\nThe new user (if email is known)<\/td>\n<\/tr>\n
referral.created<\/code><\/td>\n"Your friend signed up!" notification<\/td>\nThe referrer<\/td>\n<\/tr>\n
referral.completed<\/code><\/td>\nReward confirmation, thank-you email<\/td>\nBoth referrer and referred user<\/td>\n<\/tr>\n
deferred_link.claimed<\/code><\/td>\nPersonalized onboarding based on original link context<\/td>\nThe new user<\/td>\n<\/tr>\n
link.clicked<\/code><\/td>\nRarely used for email (too high volume)<\/td>\nN\/A<\/td>\n<\/tr>\n<\/tbody><\/table><\/figure>\n\n\n\n

The key constraint: you need the recipient's email address. Webhook events carry attribution data (campaign, platform, token), not user PII. Your receiver needs to look up the email from your user database using context from the event.<\/p>\n\n\n\n

The Identity Bridge<\/h2>\n\n\n\n

Tolinku webhook events identify a deep link interaction, not a person. To send an email, you need to bridge from the event to a user record.<\/p>\n\n\n\n

There are two patterns:<\/p>\n\n\n\n

Pattern 1: Lookup on Referral Token<\/h3>\n\n\n\n

For referral events (referral.created<\/code>, referral.completed<\/code>), the event data includes a token that maps to a referral. Your backend knows which user created that referral link. Query your database to find the referrer's email.<\/p>\n\n\n\n

async function getEmailForEvent(event: any): Promise<string | null> {\n  const { event: eventType, data } = event;\n\n  if (eventType === 'referral.created' || eventType === 'referral.completed') {\n    \/\/ Look up the referrer by the referral token\n    const referrer = await db.query(\n      'SELECT email FROM users WHERE referral_token = $1',\n      [data.token]\n    );\n    return referrer.rows[0]?.email || null;\n  }\n\n  if (eventType === 'install.tracked') {\n    \/\/ The install event itself doesn't carry an email.\n    \/\/ Store the attribution data and send the email when the user registers.\n    \/\/ Your registration flow should check for pending attribution and trigger the email.\n    return null;\n  }\n\n  return null;\n}\n<\/code><\/pre>\n\n\n\n
Pattern 2: Deferred Email Trigger<\/h3>\n\n\n\n
For install events, you typically can't send an email immediately because you don't know the user's email yet. Instead:<\/p>\n\n\n\n
    \n
  1. Store the webhook event attribution data (campaign, platform, token) in a temporary table<\/li>\n
  2. When the user registers and provides their email, match the attribution data<\/li>\n
  3. Trigger the appropriate email sequence at that point<\/li>\n<\/ol>\n\n\n\n
    This means the email isn't truly triggered by the webhook alone. The webhook provides the attribution context; the registration event provides the identity. Together, they trigger a personalized email.<\/p>\n\n\n\n
    SendGrid Integration<\/h2>\n\n\n\n
    SendGrid's API<\/a> is straightforward for transactional emails.<\/p>\n\n\n\n
    Transactional Email on Referral Completion<\/h3>\n\n\n\n
    import crypto from 'crypto';\nimport express from 'express';\n\nconst app = express();\napp.use('\/webhooks', express.raw({ type: 'application\/json' }));\n\nconst WEBHOOK_SECRET = process.env.WEBHOOK_SECRET!;\nconst SENDGRID_API_KEY = process.env.SENDGRID_API_KEY!;\n\napp.post('\/webhooks\/tolinku', async (req, res) => {\n  const signature = req.headers['x-webhook-signature'] as string;\n  const expected = crypto\n    .createHmac('sha256', WEBHOOK_SECRET)\n    .update(req.body)\n    .digest('hex');\n\n  if (signature !== expected) {\n    return res.status(401).send('Invalid signature');\n  }\n\n  res.status(200).send('OK');\n\n  const event = JSON.parse(req.body.toString());\n  await handleEvent(event);\n});\n\nasync function handleEvent(event: any) {\n  if (event.event === 'referral.completed') {\n    await sendReferralRewardEmail(event);\n  }\n}\n\nasync function sendReferralRewardEmail(event: any) {\n  const referrerEmail = await getEmailForEvent(event);\n  if (!referrerEmail) return;\n\n  await fetch('https:\/\/api.sendgrid.com\/v3\/mail\/send', {\n    method: 'POST',\n    headers: {\n      'Content-Type': 'application\/json',\n      'Authorization': `Bearer ${SENDGRID_API_KEY}`,\n    },\n    body: JSON.stringify({\n      personalizations: [\n        {\n          to: [{ email: referrerEmail }],\n          dynamic_template_data: {\n            reward_type: 'credit',\n            reward_amount: '$10',\n            referred_date: new Date(event.timestamp).toLocaleDateString(),\n          },\n        },\n      ],\n      from: { email: 'rewards@example.com', name: 'Your App' },\n      template_id: process.env.SENDGRID_REFERRAL_TEMPLATE_ID,\n    }),\n  });\n\n  console.log(`Referral reward email sent to ${referrerEmail}`);\n}\n<\/code><\/pre>\n\n\n\n
    Dynamic Templates<\/h3>\n\n\n\n
    SendGrid's dynamic templates<\/a> let you design the email in SendGrid's editor and pass variables from your webhook handler. Create templates for:<\/p>\n\n\n\n