Pinterest Conversions API: the 2026 setup manual

Pinterest is unusually sensitive to browser-side signal loss because its buying journey is slow and discovery-led. A person may save an idea, compare products, leave the site, return from a board days later, and purchase after another visit. Pinterest attribution commonly uses a 30-day click window and a 1-day view window, which means the platform needs durable links between the ad interaction and the eventual conversion. Safari ITP, short cookie lifetimes, ad blockers, checkout redirects, and consent changes all make that link weaker when you rely on the browser Tag alone. CAPI restores part of the path by sending the final conversion from your server with the original browser context, hashed first-party identifiers, and the epik click identifier when it exists.

Pinterest will process some sparse events, but sparse payloads give the platform little to match or optimize. Use this table as the production contract for web commerce, lead, and checkout events. The important rule is consistency: event names, IDs, timestamps, and value fields should mean the same thing in the Pinterest Tag, CAPI, analytics, and your backend logs.

epik is Pinterest's first-party click identifier. When a user lands from a Pinterest ad, Pinterest can append an epik value to the URL and the Pinterest Tag can preserve that value in browser storage. For CAPI, the job is simple — read epik as early as possible, store it on the session or cart, and forward the same value with later server events. If the purchase happens after a payment redirect, your order webhook will not be able to recover the original ad click unless you already attached epik to the checkout state.

The closest Meta comparison is fbp, but the roles are not identical. fbp is a browser identifier created by Meta Pixel to recognize the browser over time; epik is closer to a Pinterest click identifier that proves the session came from a Pinterest ad. Both are sent raw, not hashed. Both should be captured before the browser context changes. Neither replaces deterministic user_data such as hashed email or phone.

function readPinterestEpik() {
  const params = new URLSearchParams(window.location.search);
  const fromUrl = params.get("epik");
  const fromCookie = document.cookie
    .split("; ")
    .find((part) => part.startsWith("_epik="))
    ?.split("=")[1];

  return fromUrl || fromCookie || null;
}

await fetch("/api/cart/context", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    epik: readPinterestEpik(),
    user_agent: navigator.userAgent
  })
});

Deduplication prevents the Pinterest Tag and CAPI from turning one user action into two conversion candidates. Generate one event_id for each meaningful action, pass it to the browser Tag, and send the same value in the server payload. A useful convention is source_entity_action: cart_10492_add, chk_10492_start, or ord_10492_purchase. The ID should be unique per action, readable in diagnostics, and stable across retries.

const eventId = "ord_10492_purchase";

pintrk("track", "checkout_complete", {
  event_id: eventId,
  value: 129.95,
  currency: "EUR",
  order_id: "10492"
});

await fetch("/api/tracklayer/pinterest-capi", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    event_name: "checkout_complete",
    action_source: "web",
    event_time: Math.floor(Date.now() / 1000),
    event_id: eventId,
    user_data: {
      em: [sha256(normalizeEmail(customer.email))],
      epik: readPinterestEpik(),
      client_user_agent: navigator.userAgent
    },
    custom_data: {
      value: 129.95,
      currency: "EUR",
      content_ids: ["SKU-481"]
    }
  })
});

Pinterest's equivalent to Meta Event Match Quality is the Pinterest Match Rate score. It reflects whether the platform has enough permitted identifiers and context to connect server events with Pinterest users and ad interactions. A higher score does not guarantee more revenue, but it usually means your payloads are less anonymous and easier to use for attribution and optimization.

Pinterest cannot treat user-denied consent as a technical detail. If advertising storage, ad measurement, or sale or sharing choices are denied under your regional policy, your server pipeline should either suppress the Pinterest event or remove identifiers that are no longer eligible. The important part is symmetry: the browser Tag and CAPI destination must respect the same CMP decision.

A durable pattern is to capture consent at the event edge, attach it to the event envelope, and evaluate destination rules just before dispatch. With denied ad consent, TrackLayer-style routing can keep the internal order event for analytics or operations while withholding Pinterest user_data, epik, or the full event according to your legal basis and platform configuration.