Script Tag

Lightweight browser SDK. No build step. Single script tag. Sends events via sendBeacon with XHR fallback.

Installation

<script
  src="https://cdn.wirelog.ai/public/wirelog.js"
  data-key="pk_your_public_key"
></script>

Script attributes

Attribute	Required	Description
data-key	Yes	Public API key (pk_...)
data-host	No	API base URL. Falls back to inferring from script src. Only needed if CDN and API are on different hosts.
data-consent	No	"true" to require optIn() before any tracking
data-auto	No	"false" to disable automatic page_view on load
data-spa	No	SPA navigation tracking. On by default. Set to "false" to disable.
data-env	No	Choice result environment. Defaults to production.
data-choice-seed	No	Stable choice assignment seed, usually your project ID. Defaults to the API key.

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Automatic behavior

• Tracks page_view on page load (unless data-auto="false")
• SPA mode (on by default) intercepts pushState, replaceState, and popstate to fire page_view on navigation. Disable with data-spa="false".
• Auto-injects event context on all tracked events: url, language, timezone
• Marks tracked events as clientOriginated: true
• Auto-captured page_view properties include: url, previous_url, referrer, title, referring_domain, viewport/screen size, attribution params (utm_*, gclid, fbclid)

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Batching and delivery

• Events queue locally, flush on 10 events or every 2 seconds
• Uses navigator.sendBeacon for reliable delivery on page close; falls back to XHR if sendBeacon returns false
• Flushes on visibilitychange (hidden) and pagehide

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Identity management

Storage	Key	Persistence
device_id	wl_did in localStorage	Permanent until reset() or optOut()
session_id	wl_sid in sessionStorage	Reused in-tab, regenerated after 30 minutes of inactivity
user_id	wl_uid in localStorage	Set via identify(), cleared via reset()

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Queue

• Capped at 500 events
• On overflow, oldest events are dropped (FIFO eviction)

---

API reference

Available as window.wirelog and window.wl.

wl.track(eventType, eventProps?, userProps?)

Track a custom event.

wl.track("button_click", { button: "signup" });

wl.track("purchase", { amount: 49.99, plan: "pro" }, { plan: "pro" });

wl.identify(userId, userProps?, userPropOps?)

Set the user ID, persist it in localStorage, and send a POST /identify call.

wl.identify("alice@acme.org", { plan: "pro" });

wl.identify("alice@acme.org", null, {
  $set: { plan: "enterprise" },
  $set_once: { signup_source: "organic" },
  $add: { login_count: 1 },
  $unset: ["legacy_flag"]
});

The user ID is attached to all subsequent track() calls until reset().

wl.reset()

Clear identity state. Use on logout.

wl.reset();

Removes user_id, device_id, and session_id. Generates a new device_id.

wl.optIn()

Enable tracking and persist consent in localStorage (wl_consent).

wl.optIn();

wl.optOut()

Disable tracking. Clears the event queue and all stored identifiers.

wl.optOut();

wl.flush()

Manually flush the event queue.

wl.flush();

Choices

choice() resolves synchronously, then records the exposure through the normal async event queue. Call identify() first for user-level experiments, or visitor() for anonymous device-level tests.

wl.identify("u_123");

const headline = wl.choice("landing_h1", [
  { key: "welcome", value: "landing.h1.welcome" },
  { key: "best", value: "landing.h1.best" },
]);

Weighted variants use { key, value, weight }. Use assignment() when you need the selected variant key in application code.

For internationalized copy, keep variant key stable and translate the selected value after assignment. choice_version ignores value, so translation edits do not rebucket users while keys and weights are unchanged.

Use data-choice-seed to preserve assignments across API key rotation:

<script src="https://cdn.wirelog.ai/public/wirelog.js"
        data-key="pk_your_key"
        data-choice-seed="proj_your_project_id"></script>

---

Consent mode

Set data-consent="true" on the script tag. No events are tracked or queued until optIn() is called. Consent state persists in localStorage across page loads.

<script
  src="https://cdn.wirelog.ai/public/wirelog.js"
  data-key="pk_your_key"
  data-consent="true"
></script>

<script>
  // After user grants consent:
  wl.optIn();
</script>