Conversions API

When you finish this page an offline conversion (deal closed, lead qualified, trial converted, purchase) reaches LinkedIn through POST /v1/ads/conversions, the same endpoint you use for Meta and Google. Zernio uses the LinkedIn account you already connected, so there is no separate Conversions API token to generate in Campaign Manager. Send PII as plaintext: Zernio SHA-256 hashes it per LinkedIn's spec before anything reaches LinkedIn (externalId is passed through as plaintext, per LinkedIn's requirement).

Step 1: find or create a conversion rule

Call GET /v1/accounts/{accountId}/conversion-destinations. It returns every CONVERSIONS_API rule across every sponsored ad account the connected token can access, each with the adAccountId you pass back on later calls.

import Zernio from '@zernio/node';

const zernio = new Zernio();

const { data: destinations } = await zernio.conversions.listConversionDestinations({
  path: { accountId: '66b2e19d8c3f5a7e9d0b1c2d' }
});

console.log(destinations.destinations);

Response (200):

{
  "platform": "linkedinads",
  "destinations": [
    { "id": "25639412", "name": "Trial activation", "type": "LEAD", "status": "active", "adAccountId": "517258773" }
  ]
}

To create a rule, call POST /v1/accounts/{accountId}/conversion-destinations. A LinkedIn rule binds an event type (LEAD, PURCHASE, ADD_TO_CART, ...) to the destination. By default the new rule is auto-associated with every campaign in the ad account; pass autoAssociationType: "OBJECTIVE_BASED" to associate only the campaigns whose objective matches the rule type, or "NONE" to opt out and manage associations explicitly (Step 3).

const { data: rule } = await zernio.conversions.createConversionDestination({
  path: { accountId: '66b2e19d8c3f5a7e9d0b1c2d' },
  body: {
    adAccountId: '517258773',
    name: 'Trial activation',
    type: 'Lead',
    attributionType: 'LAST_TOUCH_BY_CAMPAIGN'
  }
});

console.log(rule.destination.id);

Response (201):

{
  "platform": "linkedinads",
  "destination": { "id": "25639412", "name": "Trial activation", "type": "LEAD", "status": "active", "adAccountId": "517258773" }
}

The attribution windows keep LinkedIn's defaults unless you set them: postClickAttributionWindowSize (default 30 days) and viewThroughAttributionWindowSize (default 7 days) each take 1, 7, 30, 90 or 365, and 365 only for the LEAD, PURCHASE, ADD_TO_CART, QUALIFIED_LEAD and SUBMIT_APPLICATION rule types.

adAccountId is numeric or urn:li:sponsoredAccount:.... type is a unified name or a LinkedIn enum ("QUALIFIED_LEAD", "OUTBOUND_CLICK") for types outside the unified set:

Creation is not idempotent on LinkedIn: a retry creates a second rule.

Step 2: send a conversion event

Call POST /v1/ads/conversions with accountId, the rule id as destinationId and the events.

const { data: sent } = await zernio.conversions.sendConversions({
  body: {
    accountId: '66b2e19d8c3f5a7e9d0b1c2d',
    destinationId: rule.destination.id,
    events: [{
      eventName: 'Lead',
      eventTime: 1798848000,
      eventId: 'order_abc_123',
      value: 42.5,
      currency: 'USD',
      user: {
        email: 'customer@example.com',
        firstName: 'Jane',
        lastName: 'Doe',
        country: 'US',
        clickIds: { li_fat_id: 'AQH...' }
      }
    }]
  }
});

console.log(sent.eventsReceived, sent.eventsFailed);

Response (200):

{
  "platform": "linkedinads",
  "eventsReceived": 1,
  "eventsFailed": 0,
  "failures": []
}

eventName is informational on LinkedIn: the rule's type, set at creation, decides the conversion category. clickIds.li_fat_id is optional and improves the match rate; capture it from li_fat_id on landing-page URLs after enabling enhanced conversion tracking on the LinkedIn Insight Tag.

User identifiers

LinkedIn requires at least one of: a SHA-256-hashed email, a LinkedIn first-party click id (li_fat_id), an Acxiom or Oracle MOAT identifier, or both firstName and lastName. Send as many as you have; hashed identifiers improve the match rate.

Deduplication

Pass a stable eventId on every event. If you also fire the LinkedIn Insight Tag with the same event id, LinkedIn discards the Conversions API copy and counts only the Insight Tag event (Idempotency covers the same rule on posts).

Step 3: associate campaigns

By default createConversionDestination auto-associates the new rule with every active, paused and draft campaign in the ad account (autoAssociationType: "ALL_CAMPAIGNS"). Auto-association runs once at create time, so campaigns added later need an explicit association with POST /v1/accounts/{accountId}/conversion-destinations/{destinationId}/associations:

curl -X POST "https://zernio.com/api/v1/accounts/66b2e19d8c3f5a7e9d0b1c2d/conversion-destinations/25639412/associations" \
  -H "Authorization: Bearer $ZERNIO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "adAccountId": "517258773", "campaignIds": ["337643194", "345396555"] }'

Response (200), a per-campaign result so you can retry only the rows that failed:

{
  "platform": "linkedinads",
  "succeeded": ["337643194"],
  "failed": [{ "campaignId": "345396555", "reason": "Campaign objective does not match the rule type" }]
}

Attribution metrics

Read conversion attribution back from LinkedIn's adAnalytics endpoint, pivoted by date, with GET /v1/accounts/{accountId}/conversion-destinations/{destinationId}/metrics:

curl "https://zernio.com/api/v1/accounts/66b2e19d8c3f5a7e9d0b1c2d/conversion-destinations/25639412/metrics?adAccountId=517258773&startDate=2027-01-01&endDate=2027-01-31&granularity=DAILY" \
  -H "Authorization: Bearer $ZERNIO_API_KEY"

Response (200):

{
  "platform": "linkedinads",
  "granularity": "DAILY",
  "rows": [
    {
      "start": "2027-01-01",
      "end": "2027-01-01",
      "metrics": {
        "externalWebsiteConversions": 4,
        "externalWebsitePostClickConversions": 3,
        "externalWebsitePostViewConversions": 1,
        "conversionValueInLocalCurrency": 170,
        "qualifiedLeads": 0,
        "costInLocalCurrency": 38.2
      }
    }
  ]
}

LinkedIn's retention rules apply: granularity=DAILY covers roughly the last 6 months; MONTHLY and YEARLY extend to 24 months; granularity=ALL with a range over 6 months rounds to month boundaries.

Soft delete

LinkedIn does not expose a hard delete on conversion rules. DELETE /v1/accounts/{accountId}/conversion-destinations/{destinationId}?adAccountId=517258773 flips enabled: false (the same operation Campaign Manager's delete performs), and the rule remains fetchable as status: "inactive".

Limits

• LinkedIn's BATCH_CREATE cap is 5,000 events, and Zernio chunks a larger events array into 5,000-event calls for you. Each chunk is all-or-nothing on LinkedIn's side.
• 600 requests per minute and 300,000 per day per token (LinkedIn-side).
• eventTime must be within the last 90 days. Zernio does not enforce the bound, so an older event reaches LinkedIn and is rejected there.

If it fails

A 403 with code linkedin_reconnect_required on any call here means the connection lacks rw_conversions:

{
  "error": "The LinkedIn connection lacks the rw_conversions scope. Reconnect the account.",
  "type": "permission_error",
  "code": "linkedin_reconnect_required"
}

Send the user through the LinkedIn connect flow again (scopes) and repeat the call.

Related

• Analytics: firmographic breakdowns of the same campaigns.
• Meta Ads Conversions API and Google Ads conversions: the same endpoint on the other networks.
• Send conversions and Create a conversion destination: every field.