Share Link Generation

Create unique, trackable share URLs for each user and each shareable resource. Every share link carries attribution (who shared, what they shared, where they shared it) so the viral loop funnel is fully measurable.

Approach

Generate a short URL per (user, resource, channel) tuple. When a recipient clicks the link, record the click with full attribution, then redirect to the shared resource. The click data feeds the viral coefficient calculation.

Tools (pick one)

| Tool | Method | Strengths | |------|--------|-----------| | Custom API | Your own /api/share endpoint + database table | Full control, no external dependency, free | | Dub.co | REST API for branded short links | Built-in analytics, team features, generous free tier (1,000 links/mo) | | Short.io | REST API for custom-domain short links | Custom domains, bulk creation, API-first | | Rebrandly | REST API for branded links | Enterprise features, UTM builder | | Bitly | REST API for short links | Widely recognized, but limited free tier |

Implementation (Custom API — default stack)

1. Create the share links table

CREATE TABLE share_links (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  short_code VARCHAR(12) UNIQUE NOT NULL,
  sharer_user_id UUID NOT NULL REFERENCES users(id),
  resource_type VARCHAR(50) NOT NULL,  -- 'dashboard', 'report', 'achievement', 'workspace'
  resource_id UUID NOT NULL,
  channel VARCHAR(20),  -- 'twitter', 'linkedin', 'email', 'slack', 'copy'
  created_at TIMESTAMPTZ DEFAULT NOW(),
  click_count INT DEFAULT 0,
  signup_count INT DEFAULT 0,
  metadata JSONB DEFAULT '{}'
);

CREATE TABLE share_clicks (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  share_link_id UUID NOT NULL REFERENCES share_links(id),
  clicked_at TIMESTAMPTZ DEFAULT NOW(),
  referrer VARCHAR(500),
  user_agent VARCHAR(500),
  ip_hash VARCHAR(64),
  converted BOOLEAN DEFAULT FALSE,
  converted_user_id UUID
);

2. Generate share link endpoint

POST /api/share
Authorization: Bearer {user_token}
Content-Type: application/json

{
  "resource_type": "dashboard",
  "resource_id": "abc-123",
  "channel": "linkedin"
}

Response 201:
{
  "share_url": "https://yourapp.com/s/Xk9mP2",
  "og_image_url": "https://yourapp.com/api/og?title=My+Dashboard&user=Jane",
  "share_text": "Check out my dashboard on YourProduct"
}

The endpoint:

1. Generates a unique short_code (6-8 alphanumeric characters)
2. Creates the share_links row
3. Returns the share URL, pre-generated OG image URL, and suggested share text
4. Fires a PostHog event: share_link_created with properties resource_type, resource_id, channel

3. Handle share link clicks

GET /s/{short_code}

The redirect handler:

1. Looks up the share_links row by short_code
2. Increments click_count
3. Creates a share_clicks row with referrer, user agent, IP hash
4. Fires a PostHog event: share_link_clicked with properties sharer_user_id, resource_type, channel
5. Sets a first-party cookie ref={short_code} (30-day expiry) for signup attribution
6. Redirects (302) to the shared resource URL with ?ref={short_code} query parameter

4. Track conversions

When a new user signs up, check for the ref cookie or query parameter:

1. Look up the share_links row by short_code
2. Increment signup_count on the share link
3. Update the share_clicks row: set converted = TRUE, converted_user_id
4. Fire PostHog event: share_referral_converted with sharer_user_id, referee_user_id, resource_type, channel
5. Notify the sharer (via Intercom or Loops) that their share led to a signup

Implementation (Dub.co API)

# Create a share link via Dub.co API
curl -X POST https://api.dub.co/links \
  -H "Authorization: Bearer {DUB_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://yourapp.com/shared/dashboard/abc-123?ref=user_456",
    "domain": "share.yourapp.com",
    "key": "Xk9mP2",
    "tagIds": ["share", "dashboard"],
    "externalId": "user_456_dashboard_abc-123_linkedin"
  }'

Retrieve click analytics:

curl "https://api.dub.co/analytics?linkId={link_id}&event=clicks&interval=30d" \
  -H "Authorization: Bearer {DUB_API_KEY}"

Error Handling

• Duplicate short code: regenerate with retry (collision probability is negligible with 8-char alphanumeric codes)
• Resource not found: redirect to a generic "this content is no longer available" page with a signup CTA
• Rate limiting: cap share link creation at 50/user/day to prevent abuse