refactor conversion API to avoid facebook-nodejs-business-sdk

uses direct meta graph endpoints instead.

package.json

@@ -4,7 +4,7 @@
 		"type": "git",
 		"url": "https://gitea.auvem.com/svelte-toolkit/spectator.git"
 	},
-	"version": "0.0.2",
+	"version": "0.0.6",
 	"license": "MIT",
 	"scripts": {
 		"dev": "vite dev",
@@ -36,7 +36,7 @@
 	},
 	"peerDependencies": {
 		"@sveltejs/kit": "^2.0.0",
-		"svelte": "^5.0.0"
+		"svelte": "^5.40.0"
 	},
 	"devDependencies": {
 		"@eslint/compat": "^1.4.0",
@@ -62,8 +62,11 @@
 		"svelte"
 	],
 	"dependencies": {
+		"@types/facebook-nodejs-business-sdk": "^23.0.0",
 		"@types/umami": "^2.10.1",
-		"loglevel": "^1.9.2"
+		"http-status-codes": "^2.3.0",
+		"loglevel": "^1.9.2",
+		"valibot": "^1.2.0"
 	},
 	"publishConfig": {
 		"registry": "https://gitea.auvem.com/api/packages/svelte-toolkit/npm/"

pnpm-lock.yaml

@@ -8,12 +8,21 @@ importers:
 
   .:
     dependencies:
+      '@types/facebook-nodejs-business-sdk':
+        specifier: ^23.0.0
+        version: 23.0.0
       '@types/umami':
         specifier: ^2.10.1
         version: 2.10.1
+      http-status-codes:
+        specifier: ^2.3.0
+        version: 2.3.0
       loglevel:
         specifier: ^1.9.2
         version: 1.9.2
+      valibot:
+        specifier: ^1.2.0
+        version: 1.2.0(typescript@5.9.3)
     devDependencies:
       '@eslint/compat':
         specifier: ^1.4.0
@@ -473,6 +482,9 @@ packages:
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
+  '@types/facebook-nodejs-business-sdk@23.0.0':
+    resolution: {integrity: sha512-k9saLiTd4kvBCdBHEpTyDMYlqSsiDw0yHs2ePe5M1PTIldtdtNOGx73Gtu8dQqbTAlwBWbiG3VfI+9s45Cf88w==}
+
   '@types/json-schema@7.0.15':
     resolution: {integrity: sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA==}
 
@@ -770,6 +782,9 @@ packages:
     resolution: {integrity: sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==}
     engines: {node: '>=8'}
 
+  http-status-codes@2.3.0:
+    resolution: {integrity: sha512-RJ8XvFvpPM/Dmc5SV+dC4y5PCeOhT3x1Hq0NU3rjGeg5a/CqlhZ7uudknPwZFz4aeAXDcbAyaeP7GAo9lvngtA==}
+
   ignore@5.3.2:
     resolution: {integrity: sha512-hsBTNUqQTDwkWtcdYI2i06Y/nUBEsNEDJKjWdigLvegy8kDuJAS8uRlpkkcQpyEXL0Z/pjDy5HBmMjRCJ2gq+g==}
     engines: {node: '>= 4'}
@@ -1086,6 +1101,14 @@ packages:
   util-deprecate@1.0.2:
     resolution: {integrity: sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==}
 
+  valibot@1.2.0:
+    resolution: {integrity: sha512-mm1rxUsmOxzrwnX5arGS+U4T25RdvpPjPN4yR0u9pUBov9+zGVtO84tif1eY4r6zWxVxu3KzIyknJy3rxfRZZg==}
+    peerDependencies:
+      typescript: '>=5'
+    peerDependenciesMeta:
+      typescript:
+        optional: true
+
   vite@7.3.0:
     resolution: {integrity: sha512-dZwN5L1VlUBewiP6H9s2+B3e3Jg96D0vzN+Ry73sOefebhYr9f94wwkMNN/9ouoU8pV1BqA1d1zGk8928cx0rg==}
     engines: {node: ^20.19.0 || >=22.12.0}
@@ -1447,6 +1470,8 @@ snapshots:
 
   '@types/estree@1.0.8': {}
 
+  '@types/facebook-nodejs-business-sdk@23.0.0': {}
+
   '@types/json-schema@7.0.15': {}
 
   '@types/node@24.10.4':
@@ -1791,6 +1816,8 @@ snapshots:
 
   has-flag@4.0.0: {}
 
+  http-status-codes@2.3.0: {}
+
   ignore@5.3.2: {}
 
   ignore@7.0.5: {}
@@ -2094,6 +2121,10 @@ snapshots:
 
   util-deprecate@1.0.2: {}
 
+  valibot@1.2.0(typescript@5.9.3):
+    optionalDependencies:
+      typescript: 5.9.3
+
   vite@7.3.0(@types/node@24.10.4):
     dependencies:
       esbuild: 0.27.1

src/lib/MetaPixel.svelte

@@ -1,221 +0,0 @@
-<script lang="ts" module>
-	export class PixelControl {
-		private _pixelID: string;
-		private _testEventCode?: string = undefined;
-		private _trackingManager: MaybeGetter<TrackingManager | undefined>;
-
-		private static _baseLoaded: boolean = false;
-
-		static get baseLoaded(): boolean {
-			return this._baseLoaded;
-		}
-
-		/**
-		 * Ensures that the Meta Pixel base has been loaded before
-		 * allowing further operations.
-		 * @throws Error if the Meta Pixel API is not loaded.
-		 */
-		static loadGuard(): void {
-			if (!this._baseLoaded || !window._fbq) {
-				throw new Error('Meta Pixel API has not been loaded. Call PixelControl.load() first.');
-			}
-		}
-
-		private constructor(
-			trackingManager: MaybeGetter<TrackingManager | undefined>,
-			pixelID: string,
-			testEventCode?: string
-		) {
-			this._trackingManager = trackingManager;
-			this._pixelID = pixelID;
-			this._testEventCode = testEventCode;
-		}
-
-		/** Loads the Meta Pixel base script. */
-		static load() {
-			if (this._baseLoaded && window._fbq) return;
-			if (!window._fbq) {
-				PixelControl.revokeConsent(); // Initialize without consent
-				loadMetaPixel(); // Load the Meta Pixel script
-			}
-			this._baseLoaded = true;
-			log.debug('Meta Pixel base script loaded.');
-		}
-
-		/** Tells the Meta pixel that the user has given consent for tracking. */
-		static grantConsent() {
-			this.loadGuard();
-			window.fbq?.('consent', 'grant');
-			log.debug('Meta Pixel consent granted.');
-		}
-
-		/** Tells the Meta pixel that the user has revoked consent for tracking. */
-		static revokeConsent() {
-			this.loadGuard();
-			window.fbq?.('consent', 'revoke');
-			log.debug('Meta Pixel consent revoked.');
-		}
-
-		/**
-		 * Returns a PixelControl instance for the given Meta Pixel ID. If
-		 * the base Meta Pixel script has not been loaded yet, it will be
-		 * loaded automatically. Optionally sets a test event code for the Pixel.
-		 * Does NOT initialize the Pixel; call `fireInit()` on the returned instance
-		 * before tracking events.
-		 * @param trackingManager Tracking manager to handle user consent for tracking
-		 * @param pixelID Meta Pixel ID
-		 * @param options Optional settings
-		 * @returns PixelControl instance
-		 */
-		static for(
-			trackingManager: MaybeGetter<TrackingManager | undefined>,
-			pixelID: string,
-			options?: {
-				/**
-				 * if provided, events fired will always have this code attached
-				 * to prevent them from polluting real analytics data.
-				 */
-				testEventCode?: string;
-			}
-		): PixelControl {
-			PixelControl.load();
-			return new PixelControl(trackingManager, pixelID, options?.testEventCode);
-		}
-
-		/**
-		 * Initializes this pixel with the Meta Pixel API including any advanced
-		 * matching data and options.
-		 * @param advancedMatching Advanced matching data
-		 * @param initOptions Initialization options
-		 * @returns this PixelControl instance
-		 */
-		fireInit(advancedMatching?: AdvancedMatching, initOptions?: InitOptions): PixelControl {
-			PixelControl.loadGuard();
-			window.fbq('init', this._pixelID, advancedMatching, initOptions);
-			log.debug(`Meta Pixel [${this._pixelID}] initialized.`);
-			return this;
-		}
-
-		/**
-		 * Checks if the Meta Pixel has consent to track user data
-		 * and if the Pixel has been loaded.
-		 * @returns true if tracking is allowed, false otherwise.
-		 * @throws Error if the Meta Pixel is not loaded.
-		 */
-		consentGuard(): boolean {
-			PixelControl.loadGuard();
-			const trackingManager = resolveGetter(this._trackingManager);
-			return trackingManager?.haveUserConsent() ?? false;
-		}
-
-		/**
-		 * Sends a PageView event
-		 * @throws Error if the Meta Pixel is not initialized.
-		 */
-		pageView() {
-			if (!this.consentGuard()) return;
-			window.fbq('track', 'PageView', undefined, { test_event_code: this._testEventCode });
-			log.debug(
-				`Meta Pixel [${this._pixelID}] PageView event sent (test code: ${this._testEventCode}).`
-			);
-		}
-
-		/**
-		 * Tracks a standard event for this pixel (uses `trackSingle` under the hood)
-		 * @throws Error if the Meta Pixel is not initialized.
-		 */
-		track<K extends StandardEventName>(event: K, params?: EventParamsByName[K], eventID?: string) {
-			if (!this.consentGuard()) return;
-			window.fbq('trackSingle', this._pixelID, event, params, {
-				eventID,
-				test_event_code: this._testEventCode
-			});
-			log.debug(
-				`Meta Pixel [${this._pixelID}] ${event} event sent (test code: ${this._testEventCode}).`
-			);
-		}
-
-		/**
-		 * Tracks a custom event for this pixel (uses `trackSingleCustom` under the hood)
-		 * @throws Error if the Meta Pixel is not initialized.
-		 */
-		trackCustom(event: string, params?: CommonParams & CustomParams, eventID?: string) {
-			if (!this.consentGuard()) return;
-			window.fbq('trackSingleCustom', this._pixelID, event, params, {
-				eventID,
-				test_event_code: this._testEventCode
-			});
-			log.debug(
-				`Meta Pixel [${this._pixelID}] ${event} custom event sent (test code: ${this._testEventCode}).`
-			);
-		}
-	}
-</script>
-
-<script lang="ts">
-	import { onMount } from 'svelte';
-
-	import type { TrackingManager } from './tracking.svelte.ts';
-	import type {
-		EventParamsByName,
-		StandardEventName,
-		CommonParams,
-		CustomParams,
-		AdvancedMatching,
-		InitOptions
-	} from './types/fbq.js';
-	import { loadMetaPixel } from './util/meta-pixel-loader.ts';
-	import { onNavigate } from '$app/navigation';
-	import { resolveGetter, type MaybeGetter } from './util/getter.ts';
-	import log from 'loglevel';
-
-	interface Props {
-		/** Meta Pixel ID */
-		pixelID: string;
-
-		/**
-		 * If a test event code is available, events fired will always have this
-		 * code attached to prevent them from polluting real analytics data.
-		 */
-		testEventCode?: string;
-
-		/**
-		 * Controls whether page views are automatically tracked by this
-		 * component (default: true).
-		 */
-		autoPageView?: boolean;
-
-		/**
-		 * Tracking manager to handle user consent for tracking. If omitted
-		 * tracking is disabled by default until consent is granted via
-		 * PixelControl.grantConsent().
-		 */
-		trackingManager?: TrackingManager;
-	}
-
-	let { pixelID, testEventCode, autoPageView = true, trackingManager }: Props = $props();
-
-	let pixel = $state<PixelControl | null>(null);
-
-	onMount(() => {
-		if (!trackingManager) {
-			throw new Error('MetaPixel component requires a TrackingManager to manage consent.');
-		}
-		PixelControl.load();
-		pixel = PixelControl.for(trackingManager, pixelID, { testEventCode }).fireInit();
-
-		trackingManager.runWithConsent(() => {
-			if (autoPageView && pixel) {
-				pixel.pageView();
-			}
-		});
-	});
-
-	onNavigate(() => {
-		trackingManager?.runWithConsent(() => {
-			if (autoPageView && pixel) {
-				pixel.pageView();
-			}
-		});
-	});
-</script>

src/lib/Umami.svelte

@@ -25,7 +25,9 @@
 	const consentGranted = $derived(trackingManager ? trackingManager.consent === true : true);
 
 	// Development overrides to prevent dirty analytics
-	const devConsoleTag = $derived(`[dev][consent: ${consentGranted ? 'granted' : 'revoked'}]`);
+	const devConsoleTag = $derived(
+		`[Umami] [dev][consent: ${consentGranted ? 'granted' : 'revoked'}]`
+	);
 	const devOverride = {
 		track: (...args: unknown[]): Promise<string> | undefined => {
 			log.debug(`${devConsoleTag}: Track called with:`, ...args);
@@ -62,7 +64,7 @@
 		}
 	});
 
-	if (dev) log.debug('[dev]: Umami tracking disabled');
+	if (dev) log.info('[Umami] [dev]: tracking disabled');
 
 	onMount(() => {
 		if (dev) {

src/lib/conversion/client.ts

@@ -0,0 +1,94 @@
+import { getFbpFbc } from '../metapixel/fbc.ts';
+import type { TrackingManager } from '$lib/tracking.svelte';
+import {
+	capiErrorBodySchema,
+	capiResponseBodySchema,
+	type CAPIErrorBody,
+	type CAPIRequestBody,
+	type CAPIResponseBody
+} from './handle.ts';
+import type { CAPICustomerInfoParams, CAPIEvent } from './event.ts';
+import * as v from 'valibot';
+import { dev } from '$app/environment';
+
+/**
+ * Client abstracts HTTP communication with a spectator server endpoint for
+ * sending conversion events to Meta Conversions API.
+ */
+export class CAPIClient {
+	private _href: string;
+	private _trackingManager: TrackingManager;
+
+	/**
+	 * Creates a new CAPIClient.
+	 *
+	 * @param serverHref - The spectator server endpoint URL.
+	 * @param trackingManager - The tracking manager instance, used for consent status.
+	 */
+	constructor(serverHref: string, trackingManager: TrackingManager) {
+		this._href = serverHref;
+		this._trackingManager = trackingManager;
+	}
+
+	/**
+	 * Sends CAPIEvents to the server endpoint.
+	 * @param events - The array of CAPIEvents to send.
+	 * @returns A promise that resolves to the server response.
+	 * @throws Will throw an error if input or response shape validation fails.
+	 */
+	async sendEvents(events: CAPIEvent[]): Promise<CAPIResponseBody | CAPIErrorBody> {
+		// Respond with an empty response if consent is not given
+		if (!this._trackingManager.haveUserConsent()) {
+			if (dev) {
+				console.warn(`[CAPIClient] Consent not given. Skipping sending ${events.length} event(s).`);
+			}
+			return {
+				pixelID: '',
+				fbTraceID: '',
+				receivedEvents: 0,
+				processedEvents: 0,
+				messages: []
+			};
+		}
+
+		// Attempt to build enriched user data
+		const { fbp, fbc } = getFbpFbc();
+		const enrichedUserData: Partial<CAPICustomerInfoParams> = { fbp, fbc };
+
+		// Build request body
+		const body: CAPIRequestBody = {
+			events: events.map((e) => {
+				e.enrichUserData(enrichedUserData);
+				return e.toObject();
+			})
+		};
+		v.parse(v.object({ events: v.array(v.any()) }), body); // Validate body shape
+
+		const response = await fetch(this._href, {
+			method: 'POST',
+			headers: {
+				'Content-Type': 'application/json'
+			},
+			body: JSON.stringify(body)
+		});
+		const json = await response.json();
+
+		if (response.ok) {
+			const parsed = v.parse(capiResponseBodySchema, json);
+			return parsed as CAPIResponseBody;
+		} else {
+			const parsed = v.parse(capiErrorBodySchema, json);
+			return parsed as CAPIErrorBody;
+		}
+	}
+
+	/**
+	 * Shorthand for sending a single CAPIEvent to the server endpoint.
+	 * @param event - The CAPIEvent to send.
+	 * @returns A promise that resolves to the server response.
+	 * @throws Will throw an error if input or response shape validation fails.
+	 */
+	async trackEvent(event: CAPIEvent): Promise<CAPIResponseBody | CAPIErrorBody> {
+		return this.sendEvents([event]);
+	}
+}

src/lib/conversion/connector.ts

@@ -0,0 +1,97 @@
+import { dev } from '$app/environment';
+import log from 'loglevel';
+import type { CAPIEvent } from './event.ts';
+
+const GRAPH_VERSION = 'v24.0';
+
+/**
+ * Response body from Meta Conversion API after sending events.
+ */
+export type CAPIRequestResponseBody = {
+	/** Dataset or Pixel ID to which the event successfully posted. */
+	pixelID: string;
+	/** fbtrace_id for debugging purposes. */
+	fbtrace_id: string;
+	/** Number of events received that were sent by the request. */
+	receivedEvents: number;
+	/** Number of events successfully posted by the request. */
+	processedEvents: number;
+	/** Messages returned by the server. */
+	messages: string[];
+};
+
+/**
+ * Connector class for Meta Conversion API (CAPI). Abstraction over direct HTTP
+ * requests to Meta's CAPI endpoint.
+ *
+ * See https://developers.facebook.com/docs/marketing-api/conversions-api/get-started
+ * for more information.
+ */
+export class CAPIConnector {
+	private _accessToken: string;
+	private _pixelID: string;
+	private _testEventCode?: string;
+
+	/**
+	 * Creates a new MCAPIControl instance.
+	 *
+	 * @param accessToken - Your Meta Pixel Conversion API access token.
+	 * @param pixelID - Your Meta Pixel ID.
+	 * @param testEventCode - Optional test event code used for all events if provided.
+	 */
+	constructor(accessToken: string, pixelID: string, testEventCode?: string) {
+		this._accessToken = accessToken;
+		this._pixelID = pixelID;
+		this._testEventCode = testEventCode;
+	}
+
+	/**
+	 * Sends conversion events to the Meta Conversion API.
+	 *
+	 * @param events - Array of CAPIEvent instances to send.
+	 * @returns The response from the Meta CAPI.
+	 * @throws Will throw an error if the request fails or the API returns an error.
+	 */
+	async sendEvents(events: CAPIEvent[]): Promise<CAPIRequestResponseBody> {
+		if (dev && !this._testEventCode) {
+			log.warn(
+				`[CAPIConnector] Sending ${events.length} event(s) in dev mode without a test event code. ` +
+					'Consider providing a test event code to avoid affecting real data.'
+			);
+		}
+
+		const url = `https://graph.facebook.com/${GRAPH_VERSION}/${this._pixelID}/events?access_token=${this._accessToken}`;
+
+		const body = {
+			data: events.map((e) => e.toObject()),
+			test_event_code: this._testEventCode
+		};
+
+		const resp = await fetch(url, {
+			method: 'POST',
+			headers: {
+				'Content-Type': 'application/json'
+			},
+			body: JSON.stringify(body)
+		});
+		const json = await resp.json();
+		console.log('CAPI response:', json);
+
+		if (!resp.ok) {
+			throw new Error(`Meta CAPI error ${resp.status}: ${JSON.stringify(json, null, 2)}`);
+		}
+
+		return {} as CAPIRequestResponseBody;
+	}
+
+	/**
+	 * Shorthand for sending a single event to the Meta Conversion API.
+	 *
+	 * @param event - The CAPIEvent instance to send.
+	 * @returns The response from the Meta CAPI.
+	 * @throws Will throw an error if the request fails or the API returns an error.
+	 */
+	async trackEvent(event: CAPIEvent): Promise<CAPIRequestResponseBody> {
+		return this.sendEvents([event]);
+	}
+}

src/lib/conversion/event.ts

@@ -0,0 +1,329 @@
+import type { StandardEventName } from '../types/fbq.js';
+import * as v from 'valibot';
+import crypto from 'node:crypto';
+
+const sha256 = (value: string): string => {
+	return crypto.createHash('sha256').update(value).digest('hex');
+};
+
+const normPhone = (s?: string | null) => {
+	// E.164-ish: keep digits, include leading + if present
+	if (!s) return undefined;
+	const plus = s.trim().startsWith('+');
+	const digits = s.replace(/[^\d]/g, '');
+	return plus ? `+${digits}` : digits;
+};
+
+const trimPunctuation = (s: string) => {
+	return s.replace(/^[\p{P}\p{S}]+|[\p{P}\p{S}]+$/gu, '');
+};
+
+/**
+ * Supported user data fields for conversion events.
+ *
+ * See https://developers.facebook.com/docs/marketing-api/conversions-api/parameters/customer-information-parameters
+ * for an exhaustive list of Facebook's supported user data parameters. Mappings
+ * to Meta's expected keys are handled under the hood by CAPIEvent.
+ */
+export type CAPICustomerInfoParams = {
+	/** Email address (maps to `em`). */
+	email?: string;
+	/** Phone number (maps to `ph`). */
+	phone?: string;
+	/** First name (maps to `fn`). */
+	firstName?: string;
+	/** Last name (maps to `ln`). */
+	lastName?: string;
+	/** Client IP address (maps to `client_ip_address`). */
+	clientIP?: string;
+	/** Client user agent (maps to `client_user_agent`). */
+	clientUserAgent: string;
+	/** Facebook browser pixel ID (_fbp cookie). */
+	fbp?: string;
+	/** Facebook click ID (_fbc cookie). */
+	fbc?: string;
+	/** External ID (maps to `external_id`). */
+	externalID?: string;
+};
+
+/** valibot schema for meta's customer information parameters */
+const metaCustomerInfoParamsSchema = v.object({
+	em: v.optional(v.string()),
+	ph: v.optional(v.string()),
+	fn: v.optional(v.string()),
+	ln: v.optional(v.string()),
+	client_ip_address: v.optional(v.string()),
+	client_user_agent: v.string(),
+	fbp: v.optional(v.string()),
+	fbc: v.optional(v.string()),
+	external_id: v.optional(v.string())
+});
+
+/** Meta's customer information parameters with annoyingly abbreviated keys. */
+type meta_customerInfoParams = v.InferOutput<typeof metaCustomerInfoParamsSchema>;
+
+/** Maps our customer information parameters to Meta's abbreviated keys. */
+const _meta_customInfoParams_Map: Record<
+	keyof CAPICustomerInfoParams,
+	keyof meta_customerInfoParams
+> = {
+	email: 'em',
+	phone: 'ph',
+	firstName: 'fn',
+	lastName: 'ln',
+	clientIP: 'client_ip_address',
+	clientUserAgent: 'client_user_agent',
+	fbp: 'fbp',
+	fbc: 'fbc',
+	externalID: 'external_id'
+};
+
+/**
+ * Maps CAPICustomerInfoParams to meta_customerInfoParams by transforming keys.
+ * Transforms values as needed (e.g. hashing email/phone).
+ *
+ * WARNING: This function is unsafe and does not perform shape validation; ensure
+ * input shape is valid before consuming.
+ *
+ * @param data - The CAPICustomerInfoParams to map.
+ * @returns The mapped meta_customerInfoParams.
+ */
+const mapCustomerInfoToMeta = (data: Partial<CAPICustomerInfoParams>) => {
+	const dst = {} as meta_customerInfoParams; // unsafe
+	for (const key in data) {
+		const shortKey = _meta_customInfoParams_Map[key as keyof CAPICustomerInfoParams];
+		if (shortKey && data[key as keyof CAPICustomerInfoParams]) {
+			dst[shortKey] = data[key as keyof CAPICustomerInfoParams] as string;
+		}
+	}
+
+	// Transform values as needed
+
+	if (dst.em) {
+		dst.em = sha256(dst.em.trim().toLowerCase());
+	}
+	if (dst.ph) {
+		const normed = normPhone(dst.ph);
+		dst.ph = normed ? sha256(normed) : normed;
+	}
+	if (dst.fn) {
+		dst.fn = sha256(trimPunctuation(dst.fn.trim().toLowerCase()));
+	}
+	if (dst.ln) {
+		dst.ln = sha256(trimPunctuation(dst.ln.trim().toLowerCase()));
+	}
+
+	return dst;
+};
+
+/** valibot schema for standard parameters / custom data */
+const standardParamsSchema = v.object({
+	value: v.optional(v.number()),
+	net_revenue: v.optional(v.number()),
+	currency: v.optional(v.string()),
+	content_name: v.optional(v.string()),
+	content_category: v.optional(v.string()),
+	content_ids: v.optional(v.array(v.string())),
+	contents: v.optional(
+		v.array(
+			v.object({
+				id: v.optional(v.string()),
+				quantity: v.optional(v.number()),
+				item_price: v.optional(v.number()),
+				title: v.optional(v.string()),
+				description: v.optional(v.string()),
+				category: v.optional(v.string()),
+				brand: v.optional(v.string()),
+				delivery_category: v.optional(v.string())
+			})
+		)
+	),
+	content_type: v.optional(v.string()),
+	order_id: v.optional(v.string()),
+	predicted_ltv: v.optional(v.number()),
+	num_items: v.optional(v.number()),
+	search_string: v.optional(v.string()),
+	status: v.optional(v.string()),
+	item_number: v.optional(v.string()),
+	delivery_category: v.optional(v.string()),
+	custom_properties: v.optional(v.record(v.string(), v.unknown()))
+});
+
+/**
+ * Supported standard data fields typically used as custom data parameters
+ * for CAPI/Pixel events.
+ *
+ * See https://developers.facebook.com/docs/marketing-api/conversions-api/parameters/custom-data
+ * for an exhaustive list of Facebook's supported standard event parameters.
+ */
+export type CAPIStandardParams = v.InferOutput<typeof standardParamsSchema>;
+
+/** Supported action sources for conversion events. */
+export enum ActionSource {
+	Email = 'email',
+	Website = 'website',
+	App = 'app',
+	PhoneCall = 'phone_call',
+	Chat = 'chat',
+	PhysicalStore = 'physical_store',
+	SystemGenerated = 'system_generated',
+	BusinessMessaging = 'business_messaging',
+	Other = 'other'
+}
+
+/** valibot schema for server event parameters, sent directly as request */
+export const MetaServerEventParamsSchema = v.object({
+	event_name: v.string(),
+	event_time: v.number(),
+	user_data: metaCustomerInfoParamsSchema,
+	custom_data: v.optional(standardParamsSchema),
+	event_source_url: v.optional(v.string()),
+	opt_out: v.optional(v.boolean()),
+	event_id: v.optional(v.string()),
+	action_source: v.enum(ActionSource)
+});
+
+/**
+ * Internal type representing validated server event parameters, suitable to
+ * POST directly to the Meta Conversions API.
+ *
+ * See https://developers.facebook.com/docs/marketing-api/conversions-api/parameters/server-event
+ * for an exhaustive list of Facebook's supported server event parameters.
+ */
+export type MetaServerEventParams = v.InferOutput<typeof MetaServerEventParamsSchema>;
+
+/**
+ * Options for creating a CAPIEvent. All parameters are validated and
+ * transformed to Meta's expected keys by CAPIEvent.
+ */
+export type CAPIEventOptions = {
+	eventName: StandardEventName | string;
+	/** Will be set to the current date and time if not provided */
+	eventTime?: Date;
+	userData: CAPICustomerInfoParams;
+	customData?: CAPIStandardParams;
+	/** Required if actionSource is set to 'website' */
+	eventSourceURL?: string;
+	optOut?: boolean;
+	eventID?: string;
+	actionSource: ActionSource;
+};
+
+/**
+ * Represents a Meta Conversions API event with properly mapped parameters
+ * and input validation.
+ */
+export class CAPIEvent {
+	private _params?: MetaServerEventParams;
+	/** Returns Meta-compliant server event object. */
+	get params() {
+		return this._params;
+	}
+
+	private constructor() {}
+
+	/**
+	 * Creates a new CAPIEvent instance with the given options and generates a
+	 * Meta-compliant event object.
+	 *
+	 * @param opts - The options for creating the CAPIEvent.
+	 * @return The CAPIEvent instance.
+	 * @throws Will throw an error if option shape validation fails.
+	 */
+	static fromOpts(opts: CAPIEventOptions) {
+		const event = new CAPIEvent();
+
+		// Transform our customer info params to Meta's expected keys
+		const meta_customerInfo = mapCustomerInfoToMeta(opts.userData);
+
+		// Build event params & validate
+		event._params = {
+			event_name: opts.eventName,
+			event_time: Math.floor((opts.eventTime ?? new Date()).getTime() / 1000),
+			user_data: meta_customerInfo,
+			custom_data: opts.customData,
+			event_source_url: opts.eventSourceURL,
+			opt_out: opts.optOut,
+			event_id: opts.eventID,
+			action_source: opts.actionSource
+		};
+
+		event._params = v.parse(MetaServerEventParamsSchema, event._params);
+		return event;
+	}
+
+	/**
+	 * Unmashals a JSON string or object into a CAPIEvent instance and parses
+	 * its parameters to match Meta's expected shape.
+	 *
+	 * @param src - The JSON string to unmarshal.
+	 * @returns The CAPIEvent instance.
+	 * @throws Will throw an error if the JSON is invalid or fails validation.
+	 */
+	private static fromSrc(src: string | object): CAPIEvent {
+		const obj = typeof src === 'string' ? JSON.parse(src) : src;
+		const parsed = v.parse(MetaServerEventParamsSchema, obj);
+		const event = new CAPIEvent();
+		event._params = parsed;
+		return event;
+	}
+
+	/**
+	 * Unmarshals a JSON string into a CAPIEvent instance and parses its
+	 * parameters to match Meta's expected shape.
+	 *
+	 * @param str - The JSON string to unmarshal.
+	 * @returns The CAPIEvent instance.
+	 * @throws Will throw an error if the JSON is invalid or fails validation.
+	 */
+	static fromJSON(str: string): CAPIEvent {
+		return CAPIEvent.fromSrc(str);
+	}
+
+	/**
+	 * Unmarshals a plain object into a CAPIEvent instance and parses its
+	 * parameters to match Meta's expected shape.
+	 *
+	 * @param obj - The object to unmarshal.
+	 * @returns The CAPIEvent instance.
+	 * @throws Will throw an error if the object fails validation.
+	 */
+	static fromObject(obj: object): CAPIEvent {
+		return CAPIEvent.fromSrc(obj);
+	}
+
+	/**
+	 * Marshals the CAPIEvent to a JSON string suitable for sending to the Meta CAPI.
+	 * @returns The JSON string representation of the CAPIEvent.
+	 */
+	toJSON(): string {
+		return JSON.stringify(this._params);
+	}
+
+	/**
+	 * Marshals the CAPIEvent to a plain object suitable for sending to the Meta CAPI.
+	 * @returns The object representation of the CAPIEvent.
+	 */
+	toObject(): MetaServerEventParams {
+		return this._params as MetaServerEventParams;
+	}
+
+	/**
+	 * Enriches the CAPIEvent with additional user data.
+	 * @param additionalData - Additional user data to merge.
+	 * @throws Will throw an error if the enriched data fails validation.
+	 */
+	enrichUserData(additionalData: Partial<CAPICustomerInfoParams>) {
+		if (!this._params) return;
+		const additionalMetaData = mapCustomerInfoToMeta(additionalData);
+
+		// Merge additional data, only overwriting if no previous value exists
+		this._params.user_data = {
+			...additionalMetaData,
+			...this._params.user_data
+		};
+
+		// Re-validate after enrichment
+		this._params = v.parse(MetaServerEventParamsSchema, this._params);
+	}
+}

src/lib/conversion/handle.ts

@@ -0,0 +1,76 @@
+import { json, type RequestHandler } from '@sveltejs/kit';
+import { StatusCodes } from 'http-status-codes';
+import { getFbpFbcFromCookies } from '../metapixel/fbc.ts';
+import type { CAPIConnector } from './connector.ts';
+import { getRequestIP } from '../util/ip.ts';
+import * as v from 'valibot';
+import { CAPIEvent, MetaServerEventParamsSchema, type CAPICustomerInfoParams } from './event.ts';
+
+export const capiRequestBodySchema = v.object({
+	events: v.array(MetaServerEventParamsSchema)
+});
+
+/** Request body for conversion events */
+export type CAPIRequestBody = v.InferOutput<typeof capiRequestBodySchema>;
+
+export const capiErrorBodySchema = v.object({
+	error: v.string()
+});
+
+/** Returned by the conversion request handler in case of an error */
+export type CAPIErrorBody = v.InferOutput<typeof capiErrorBodySchema>;
+
+export const capiResponseBodySchema = v.object({
+	pixelID: v.string(),
+	fbTraceID: v.string(),
+	receivedEvents: v.number(),
+	processedEvents: v.number(),
+	messages: v.array(v.string())
+});
+
+/** Returned by the conversion request handler in case of a successful response */
+export type CAPIResponseBody = v.InferOutput<typeof capiResponseBodySchema>;
+
+/**
+ * Creates a SvelteKit request handler for processing conversion events.
+ *
+ * @param connector - The CAPIConnector instance to send events through.
+ * @returns A SvelteKit RequestHandler function.
+ */
+export const createCAPIHandler: (connector: CAPIConnector) => RequestHandler = (connector) => {
+	const handle: RequestHandler = async ({ request, getClientAddress, cookies }) => {
+		try {
+			const json = await request.json();
+			const parsed = v.parse(capiRequestBodySchema, json);
+
+			// Build enriched user data with IP, user agent, and fbp/fbc from cookies
+			const ip = getRequestIP(request, getClientAddress);
+			const ua = request.headers.get('user-agent') ?? undefined;
+			const { fbp, fbc } = getFbpFbcFromCookies(cookies);
+
+			const enrichedUserData: Partial<CAPICustomerInfoParams> = {
+				clientIP: ip,
+				clientUserAgent: ua,
+				fbp,
+				fbc
+			};
+
+			// Enrich each event's user data
+			const events: CAPIEvent[] = parsed.events.map((eventParams) => {
+				const event = CAPIEvent.fromObject(eventParams);
+				event.enrichUserData(enrichedUserData);
+				return event;
+			});
+
+			// Send the event via the control
+			const response = await connector.sendEvents(events);
+			return json(response, { status: StatusCodes.OK });
+		} catch (e) {
+			const response: CAPIErrorBody = { error: e instanceof Error ? e.message : String(e) };
+			return json(response, {
+				status: StatusCodes.INTERNAL_SERVER_ERROR
+			});
+		}
+	};
+	return handle;
+};

src/lib/conversion/index.ts

@@ -0,0 +1,4 @@
+export * from './event.ts';
+export * from './connector.ts';
+export * from './handle.ts';
+export * from './client.ts';

src/lib/index.ts

@@ -3,12 +3,16 @@
 import { dev } from '$app/environment';
 import log from 'loglevel';
 
+export type * from './types/conversion.d.ts';
 export type * as fbq from './types/fbq.d.ts';
-export { default as MetaPixel, PixelControl } from './MetaPixel.svelte';
+export * from './metapixel/index.ts';
 export * from './tracking.svelte.ts';
 export { default as Umami } from './Umami.svelte';
+export * from './conversion/index.ts';
 
 // set log level to debug if we're in dev mode
 if (dev) {
 	log.setLevel('debug');
+} else {
+	log.setLevel('warn');
 }

src/lib/metapixel/MetaPixel.svelte

@@ -0,0 +1,74 @@
+<!-- @component
+MetaPixel integrates the Meta (Facebook) Pixel into your Svelte application,
+allowing you to track page views and custom events while respecting user consent
+for tracking. The component manages the lifecycle of the Meta Pixel script and
+PixelControl interface.
+-->
+
+<script lang="ts">
+	import { onMount } from 'svelte';
+
+	import type { TrackingManager } from '../tracking.svelte.ts';
+	import { onNavigate } from '$app/navigation';
+	import { PixelControl, type PixelControlOptions } from './pixel-control.ts';
+	import { ensureFbc, type EnsureFbcOptions } from './fbc.ts';
+
+	interface Props {
+		/**
+		 * Tracking manager to handle user consent for tracking. If omitted
+		 * tracking is disabled by default until consent is granted via
+		 * PixelControl.grantConsent().
+		 */
+		trackingManager?: TrackingManager;
+
+		/** Meta Pixel ID */
+		pixelID: string;
+
+		/** Meta Pixel Options */
+		pixelOptions?: PixelControlOptions;
+
+		/**
+		 * Controls whether page views are automatically tracked by this
+		 * component (default: true).
+		 */
+		autoPageView?: boolean;
+	}
+
+	let { pixelID, pixelOptions, autoPageView = true, trackingManager }: Props = $props();
+
+	let pixel = $state<PixelControl | null>(null);
+
+	const fbcOptions: EnsureFbcOptions = {
+		sameSite: 'Lax'
+	};
+
+	onMount(() => {
+		if (!trackingManager) {
+			throw new Error('MetaPixel component requires a TrackingManager to manage consent.');
+		}
+		pixel = PixelControl.initialize(trackingManager, pixelID, pixelOptions);
+
+		trackingManager.runWithConsent(() => {
+			if (autoPageView && pixel) {
+				pixel.pageView();
+				ensureFbc(fbcOptions);
+			}
+		});
+	});
+
+	onNavigate(() => {
+		trackingManager?.runWithConsent(() => {
+			if (autoPageView && pixel) {
+				pixel.pageView();
+				ensureFbc(fbcOptions);
+			}
+		});
+	});
+
+	export const getPixelControl = (): PixelControl => {
+		if (!pixel) {
+			throw new Error('MetaPixel component has not been initialized yet, wait for onMount.');
+		}
+		return pixel;
+	};
+</script>

src/lib/metapixel/fbc.ts

@@ -0,0 +1,98 @@
+import type { Cookies } from '@sveltejs/kit';
+import log from 'loglevel';
+
+export type EnsureFbcOptions = {
+	days?: number; // cookie lifetime, default 180
+	domain?: string; // optional cookie domain
+	sameSite?: 'Lax' | 'Strict' | 'None'; // default Lax
+	secure?: boolean; // default inferred from location.protocol === 'https:'
+	pixelLoaded?: boolean; // if true, skip manual set and let Pixel handle it
+};
+
+function getParam(name: string): string | undefined {
+	const params = new URLSearchParams(location.search);
+	const v = params.get(name);
+	return v || undefined;
+}
+
+function getCookie(name: string): string | undefined {
+	return document.cookie
+		.split('; ')
+		.find((c) => c.startsWith(name + '='))
+		?.split('=')[1];
+}
+
+function setCookie(
+	name: string,
+	value: string,
+	{
+		days = 180,
+		domain,
+		sameSite = 'Lax',
+		secure
+	}: Pick<EnsureFbcOptions, 'days' | 'domain' | 'sameSite' | 'secure'> = {}
+) {
+	const d = new Date();
+	d.setTime(d.getTime() + days * 864e5);
+	const parts = [
+		`${name}=${encodeURIComponent(value)}`,
+		`expires=${d.toUTCString()}`,
+		'path=/',
+		`SameSite=${sameSite}`
+	];
+	if (domain) parts.push(`domain=${domain}`);
+	const isSecure = secure ?? location.protocol === 'https:';
+	if (isSecure) parts.push('Secure');
+	document.cookie = parts.join('; ');
+}
+
+function isValidFbc(value: string | undefined): boolean {
+	if (!value) return false;
+	// Expect "fb.1.<unix>.<fbclid>"
+	if (!value.startsWith('fb.1.')) return false;
+	const parts = value.split('.');
+	return parts.length >= 4 && /^\d+$/.test(parts[2]) && parts[3].length > 0;
+}
+
+/**
+ * Ensure _fbc cookie exists when landing URL contains fbclid.
+ * Call after consent. If pixelLoaded is true, it skips manual setting.
+ */
+export function ensureFbc(options: EnsureFbcOptions = {}) {
+	try {
+		const { pixelLoaded = false, ...cookieOpts } = options;
+
+		if (pixelLoaded) throw new Error('Pixel loaded, skipping manual _fbc set'); // Let the Pixel set _fbc if it’s active
+
+		const fbclid = getParam('fbclid');
+		if (!fbclid) throw new Error('No fbclid param present');
+
+		const existing = getCookie('_fbc');
+		if (isValidFbc(existing)) throw new Error('_fbc cookie already present and valid');
+
+		const ts = Math.floor(Date.now() / 1000);
+		const fbc = `fb.1.${ts}.${fbclid}`;
+		setCookie('_fbc', fbc, cookieOpts);
+		log.debug('[ensureFbc] Set _fbc cookie:', fbc);
+	} catch (e) {
+		log.debug('[ensureFbc]', (e as Error).message);
+	}
+}
+
+/**
+ * Helper to read both _fbp and _fbc for your CAPI payload from browser cookies.
+ */
+export function getFbpFbc(): { fbp?: string; fbc?: string } {
+	const fbp = getCookie('_fbp');
+	const fbc = getCookie('_fbc');
+	return { fbp, fbc };
+}
+
+/**
+ * Helper to read both _fbp and _fbc for your CAPI payload from cookies object.
+ */
+export function getFbpFbcFromCookies(cookies: Cookies): { fbp?: string; fbc?: string } {
+	const fbp = cookies.get('_fbp') || undefined;
+	const fbc = cookies.get('_fbc') || undefined;
+	return { fbp, fbc };
+}

src/lib/metapixel/index.ts

@@ -0,0 +1,4 @@
+export { default as MetaPixel } from './MetaPixel.svelte';
+export { PixelControl, type PixelControlOptions } from './pixel-control.ts';
+export * from './fbc.ts';
+export * from './pixel-control.ts';

src/lib/metapixel/pixel-control.ts

@@ -0,0 +1,326 @@
+import type { TrackingManager } from '../tracking.svelte.ts';
+import type {
+	EventParamsByName,
+	StandardEventName,
+	CommonParams,
+	CustomParams,
+	AdvancedMatching,
+	InitOptions
+} from '../types/fbq.js';
+import { loadMetaPixel } from '../util/meta-pixel-loader.ts';
+import { resolveGetter, type MaybeGetter } from '../util/getter.ts';
+import log from 'loglevel';
+import { dev } from '$app/environment';
+import { CAPIClient } from '../conversion/client.ts';
+import { ActionSource, CAPIEvent, type CAPIStandardParams } from '../conversion/event.ts';
+
+const pixelParamsToCustomData = (params: CommonParams & CustomParams): CAPIStandardParams => {
+	const customData: CAPIStandardParams = {};
+	if (params.value) customData.value = params.value;
+	if (params.currency) customData.currency = params.currency;
+	if (params.content_name) customData.content_name = params.content_name;
+	if (params.content_category) customData.content_category = params.content_category;
+	if (params.content_ids) customData.content_ids = params.content_ids;
+	if (params.contents) {
+		const acc: CAPIStandardParams['contents'] = [];
+		customData.contents = params.contents.reduce((acc, content) => {
+			acc.push({
+				id: content.id.toString(),
+				quantity: content.quantity
+			});
+			return acc;
+		}, acc);
+	}
+	if (params.num_items) customData.num_items = params.num_items;
+	if (params.search_string) customData.search_string = params.search_string;
+	if (params.predicted_ltv) customData.predicted_ltv = params.predicted_ltv;
+	return customData;
+};
+
+/**
+ * Options for configuring a PixelControl instance.
+ */
+export type PixelControlOptions = {
+	/**
+	 * if provided, events fired will always have this code attached
+	 * to prevent them from polluting real analytics data.
+	 */
+	testEventCode?: string;
+	/**
+	 * if provided, all events fired will be passed to the server endpoint
+	 * at this URL to be sent via the Conversion API. Any events sent
+	 * without a event ID will be assigned a random one.
+	 */
+	conversionHref?: string;
+	/** Advanced matching data */
+	advancedMatching?: AdvancedMatching;
+	/** Initialization options */
+	initOptions?: InitOptions;
+};
+
+/**
+ * Manages multiple Meta Pixel instances and provides methods to
+ * interact with them, including consent management and event tracking.
+ */
+export class PixelControl {
+	private _pixelID: string;
+	private _testEventCode?: string = undefined;
+	private _trackingManager: MaybeGetter<TrackingManager | undefined>;
+	private _conversionClient?: CAPIClient = undefined;
+
+	private static _baseLoaded: boolean = false;
+	private static _registeredPixels: Record<string, PixelControl> = {};
+
+	/** Indicates whether the Meta Pixel base script has been loaded. */
+	static get baseLoaded(): boolean {
+		return this._baseLoaded;
+	}
+
+	/**
+	 * Ensures that the Meta Pixel base has been loaded before
+	 * allowing further operations.
+	 * @throws Error if the Meta Pixel API is not loaded.
+	 */
+	static loadGuard(): void {
+		if (!this._baseLoaded || !window.fbq) {
+			throw new Error('Meta Pixel API has not been loaded. Call PixelControl.load() first.');
+		}
+	}
+
+	private constructor(
+		trackingManager: MaybeGetter<TrackingManager | undefined>,
+		pixelID: string,
+		options?: PixelControlOptions
+	) {
+		this._trackingManager = trackingManager;
+		this._pixelID = pixelID;
+		this._testEventCode = options?.testEventCode;
+
+		const resolvedTrackingManager = resolveGetter(trackingManager);
+		if (options?.conversionHref && resolvedTrackingManager) {
+			this._conversionClient = new CAPIClient(options.conversionHref, resolvedTrackingManager);
+		} else if (options?.conversionHref) {
+			log.warn(
+				`[PixelControl] Conversion Client ${options.conversionHref} for Meta Pixel [${this._pixelID}] not initialized, TrackingManager is required for user consent.`
+			);
+		}
+	}
+
+	/** Loads the Meta Pixel base script. */
+	static load() {
+		if (this._baseLoaded && !!window.fbq) return;
+		loadMetaPixel(); // Load the Meta Pixel script
+		this._baseLoaded = true;
+		log.debug('[PixelControl] Meta Pixel base script loaded.', this._baseLoaded);
+	}
+
+	/** Tells the Meta pixel that the user has given consent for tracking. */
+	static grantConsent() {
+		this.loadGuard();
+		window.fbq?.('consent', 'grant');
+		log.debug('[PixelControl] Pixel consent granted.');
+	}
+
+	/** Tells the Meta pixel that the user has revoked consent for tracking. */
+	static revokeConsent() {
+		this.loadGuard();
+		window.fbq?.('consent', 'revoke');
+		log.debug('[PixelControl] Pixel consent revoked.');
+	}
+
+	/**
+	 * Registers a PixelControl instance for the given Meta Pixel ID. If
+	 * the base Meta Pixel script has not been loaded yet, it will be
+	 * loaded automatically. Optionally sets a test event code for the Pixel.
+	 * Should only be called once for each Pixel ID, use PixelControl.get()
+	 * to retrieve existing instances.
+	 * @param trackingManager Tracking manager to handle user consent for tracking
+	 * @param pixelID Meta Pixel ID
+	 * @param options Optional settings
+	 * @returns PixelControl instance
+	 */
+	static initialize(
+		trackingManager: MaybeGetter<TrackingManager | undefined>,
+		pixelID: string,
+		options?: PixelControlOptions
+	): PixelControl {
+		// Load the base script if not already loaded
+		PixelControl.load();
+
+		// Check for existing PixelControl instance
+		if (this._registeredPixels[pixelID]) {
+			log.warn(
+				`[PixelControl] Instance for Meta Pixel ID: ${pixelID} already exists. Returning existing instance.`
+			);
+			return this._registeredPixels[pixelID];
+		}
+
+		// Create and register the PixelControl instance
+		const pixel = new PixelControl(trackingManager, pixelID, options);
+		this._registeredPixels[pixelID] = pixel;
+
+		// Fire initialization
+		window.fbq('init', pixel._pixelID, options?.advancedMatching, options?.initOptions);
+		log.debug(`[PixelControl] [${pixel._pixelID}] initialized.`);
+
+		return pixel;
+	}
+
+	/**
+	 * Returns an existing PixelControl instance for the given Meta Pixel ID.
+	 * @param pixelID Meta Pixel ID
+	 * @returns PixelControl instance
+	 * @throws Error if no PixelControl instance is found for the given ID.
+	 */
+	static get(pixelID: string): PixelControl {
+		const pixel = this._registeredPixels[pixelID];
+		if (!pixel) {
+			throw new Error(`No PixelControl instance found for Meta Pixel ID: ${pixelID}`);
+		}
+		return pixel;
+	}
+
+	/**
+	 * Checks if the Meta Pixel has consent to track user data
+	 * and if the Pixel has been loaded.
+	 * @returns true if tracking is allowed, false otherwise.
+	 * @throws Error if the Meta Pixel is not loaded.
+	 */
+	consentGuard(): boolean {
+		PixelControl.loadGuard();
+		const trackingManager = resolveGetter(this._trackingManager);
+		return trackingManager?.haveUserConsent() ?? false;
+	}
+
+	/**
+	 * Shorthand utility to send a PageView event
+	 * @param disableCAPI If true, disables sending this event to the Conversion API
+	 * @throws Error if the Meta Pixel is not initialized.
+	 */
+	pageView(disableCAPI: boolean = false) {
+		this.track('PageView', undefined, undefined, disableCAPI);
+	}
+
+	/**
+	 * Forwards an event to the Conversion API client if configured.
+	 *
+	 * @param event - The event name.
+	 * @param params - The event parameters.
+	 * @param eventID - Optional event ID for deduplication.
+	 * @returns The event ID used, either provided or generated.
+	 */
+	private forwardToCAPI(
+		event: StandardEventName | string,
+		params?: CommonParams & CustomParams,
+		eventID?: string
+	): string | undefined {
+		if (!this._conversionClient) return eventID;
+
+		if (!eventID) {
+			eventID = crypto.randomUUID();
+		}
+
+		this._conversionClient
+			.trackEvent(
+				CAPIEvent.fromOpts({
+					eventName: event,
+					eventID: eventID,
+					actionSource: ActionSource.Website,
+					eventTime: new Date(),
+					userData: {
+						clientUserAgent: navigator.userAgent
+					},
+					customData: params ? pixelParamsToCustomData(params) : undefined
+				})
+			)
+			.then((response) => {
+				log.debug(
+					`[PixelControl] [${this._pixelID}] ${event} event sent to Conversion API with Event ID: ${eventID}, Response: ${JSON.stringify(
+						response,
+						null,
+						2
+					)}`
+				);
+			})
+			.catch((error) => {
+				log.error(
+					`[PixelControl] [${this._pixelID}] Failed to send ${event} event to Conversion API with Event ID: ${eventID}`,
+					error
+				);
+			});
+	}
+
+	/**
+	 * Tracks a standard event for this pixel (uses `trackSingle` under the hood)
+	 * @param event Standard event name
+	 * @param params Event parameters
+	 * @param eventID Optional event ID for deduplication with Conversion API
+	 * @param disableCAPI If true, disables sending this event to the Conversion API
+	 * @throws Error if the Meta Pixel is not initialized.
+	 */
+	track<K extends StandardEventName>(
+		event: K,
+		params?: EventParamsByName[K],
+		eventID?: string,
+		disableCAPI: boolean = false
+	) {
+		if (!this.consentGuard()) return;
+
+		// Optionally, send to conversion API endpoint
+		if (!disableCAPI) {
+			eventID = this.forwardToCAPI(event, params, eventID);
+		}
+
+		// Send the event to Meta via the pixel
+		if (!dev || this._testEventCode) {
+			window.fbq('trackSingle', this._pixelID, event, params, {
+				eventID,
+				test_event_code: this._testEventCode
+			});
+			log.debug(
+				`[PixelControl] [${this._pixelID}] ${event} event sent${dev && ` (test code: ${this._testEventCode})`}.`
+			);
+		} else {
+			log.info(
+				`[PixelControl] [${this._pixelID}] ${event} event not sent in development mode without a test event code.`
+			);
+		}
+	}
+
+	/**
+	 * Tracks a custom event for this pixel (uses `trackSingleCustom` under the hood)
+	 * @param event Custom event name
+	 * @param params Event parameters
+	 * @param eventID Optional event ID for deduplication with Conversion API
+	 * @param disableCAPI If true, disables sending this event to the Conversion API
+	 * @throws Error if the Meta Pixel is not initialized.
+	 */
+	trackCustom(
+		event: string,
+		params?: CommonParams & CustomParams,
+		eventID?: string,
+		disableCAPI: boolean = false
+	) {
+		if (!this.consentGuard()) return;
+
+		// Optionally, send to conversdion API endpoint
+		if (!disableCAPI) {
+			eventID = this.forwardToCAPI(event, params, eventID);
+		}
+
+		// Send the event to Meta via the pixel
+		if (!dev || this._testEventCode) {
+			window.fbq('trackSingleCustom', this._pixelID, event, params, {
+				eventID,
+				test_event_code: this._testEventCode
+			});
+			log.debug(
+				`[PixelControl] [${this._pixelID}] ${event} custom event sent (test code: ${this._testEventCode}).`
+			);
+		} else {
+			log.info(
+				`[PixelControl] [${this._pixelID}] ${event} custom event not sent in development mode without a test event code.`
+			);
+		}
+	}
+}

src/lib/tracking.svelte.ts

@@ -1,4 +1,6 @@
-import { setContext, getContext, onDestroy } from 'svelte';
+import { browser } from '$app/environment';
+import log from 'loglevel';
+import { onDestroy, onMount, createContext } from 'svelte';
 
 /**
  * Options for initializing the TrackingManager.
@@ -36,17 +38,69 @@ type InternalService<T> = Service<T> & {
  * Manages user tracking preferences and services that require consent.
  */
 export class TrackingManager {
+	/** tracking consent, persisted to localStorage by saveOpts */
 	private _consent: boolean | null = $state(null);
 	private _services: Record<string, InternalService<unknown>> = {};
 	private _changeCallbacks: Array<(consent: boolean | null) => void> = [];
 	private _consentQueue: Array<() => void> = [];
 
+	/**
+	 * Saves consent state to localStorage if browser storage is available.
+	 * Automatically called after updating consent.
+	 * @throws Error if storage is not available.
+	 */
+	saveOpts(): TrackingManager {
+		if (!browser || !window?.localStorage) {
+			throw new Error('Cannot access localStorage to save tracking state');
+		}
+
+		window.localStorage.setItem(
+			'trackingOpts',
+			JSON.stringify({ consent: this._consent } as TrackingManagerOpts)
+		);
+		return this;
+	}
+
+	/**
+	 * Loads tracking options from localStorage if available. Suitable to call
+	 * after initialization, e.g. in onMount after a TrackingManager is created.
+	 * @throws Error if storage is not available.
+	 */
+	loadOpts(): TrackingManager {
+		if (!browser || !window?.localStorage) {
+			throw new Error('Cannot access localStorage to load tracking state');
+		}
+
+		const raw = window.localStorage.getItem('trackingOpts');
+		if (raw) {
+			const opts = JSON.parse(raw) as TrackingManagerOpts;
+			if (opts.consent !== undefined && opts.consent !== null) {
+				this.setConsent(opts.consent);
+			}
+			log.debug('[TrackingManager] Loaded tracking options from storage:', opts);
+		}
+
+		return this;
+	}
+
+	/**
+	 * Creates a TrackingManager instance.
+	 * @param opts Optional initial options.
+	 */
 	constructor(opts?: TrackingManagerOpts) {
 		if (opts) {
 			if (opts.consent !== undefined) this._consent = opts.consent;
 		}
 	}
 
+	/**
+	 * Creates a TrackingManager instance from localStorage data.
+	 * @throws Error if storage is not available.
+	 */
+	static fromLocalStorage(): TrackingManager {
+		return new TrackingManager().loadOpts();
+	}
+
 	/** Indicates whether tracking is currently allowed. */
 	get consent() {
 		return this._consent;
@@ -78,7 +132,7 @@ export class TrackingManager {
 
 	/**
 	 * Sets whether tracking is consented. If set to true, all queued callbacks
-	 * will be executed.
+	 * will be executed. Automatically persists to localStorage if available.
 	 */
 	setConsent(value: boolean) {
 		if (this._consent === value) return;
@@ -95,6 +149,7 @@ export class TrackingManager {
 		this._changeCallbacks.forEach((cb) => {
 			cb(this._consent);
 		});
+		this.saveOpts();
 	}
 
 	/**
@@ -113,16 +168,23 @@ export class TrackingManager {
 
 	/**
 	 * Runs callback immediately if we have consent already or queues it for later.
-	 * Removes callback from queue onDestroy.
 	 * @param callback The function to run when consent is granted.
 	 */
 	runWithConsent(callback: () => void) {
-		if (this._consent) {
-			callback();
-		} else {
-			this._consentQueue.push(callback);
+		if (this._consent) callback();
+		else this._consentQueue.push(callback);
 	}
 
+	/**
+	 * Runs callback onMount if we have consent already or queues it for later.
+	 * Removes the callback from the queue onDestroy.
+	 * @param callback The function to run when consent is granted.
+	 */
+	lifecycleWithConsent(callback: () => void) {
+		onMount(() => {
+			if (this._consent) callback();
+			else this._consentQueue.push(callback);
+		});
 		onDestroy(() => {
 			this._consentQueue = this._consentQueue.filter((cb) => cb !== callback);
 		});
@@ -192,19 +254,31 @@ export class TrackingManager {
 	}
 }
 
-const trackingManagerKey = Symbol();
+const [getTrackingContext, setTrackingContext] = createContext<TrackingManager>();
 
 /**
  * Gets the TrackingManager from context, or creates one if it doesn't exist.
- * @param initializer Optional initializer function to customize the TrackingManager.
+ * If called from the browser, attempts to load saved state from localStorage.
  * @returns The TrackingManager instance.
  */
 export const getTrackingManager = (): TrackingManager => {
-	const saved = getContext<TrackingManager>(trackingManagerKey);
-	if (saved) return saved;
+	try {
+		const saved = getTrackingContext();
+		if (saved) {
+			log.debug('[TrackingManager] Using existing instance from context');
+			return saved;
+		}
+	} catch {
+		// ignore missing context, we'll create a new one
+	}
+
+	log.debug('[TrackingManager] Creating new instance');
+	const manager = $state(new TrackingManager());
+	setTrackingContext(manager);
+
+	if (browser) {
+		manager.loadOpts();
+	}
 
-	console.debug('initializing a new TrackingManager');
-	const manager = new TrackingManager();
-	setContext(trackingManagerKey, manager);
 	return manager;
 };

src/lib/types/fbq.d.ts

@@ -39,7 +39,7 @@ export type CommonParams = Partial<{
 	/**
 	 * Product IDs associated with the event, such as SKUs (e.g. ["ABC123", "XYZ456"]).
 	 */
-	content_ids: (string | number)[];
+	content_ids: string[];
 
 	/**
 	 * Name of the page/product.
@@ -230,27 +230,27 @@ export type StandardEventName =
  */
 export type AdvancedMatching = {
 	/** Primary contact email (or hashed email) */
-	email?: string;
+	em?: string;
 	/** Phone number (E.164 or local) */
-	phone?: string;
+	ph?: string;
 	/** First name */
-	first_name?: string;
+	fn?: string;
 	/** Last name */
-	last_name?: string;
+	ln?: string;
 	/** City */
-	city?: string;
+	ct?: string;
 	/** State/region */
-	state?: string;
+	st?: string;
 	/** Postal / ZIP code */
-	zip?: string;
+	zp?: string;
 	/** Country code */
 	country?: string;
 	/** External id to match users (optional) */
 	external_id?: string;
 	/** Gender */
-	gender?: string;
+	ge?: string;
 	/** Date of birth (ISO-like or YYYY-MM-DD) */
-	date_of_birth?: string;
+	db?: string;
 	// allow additional provider-specific keys
 	[key: string]: string | undefined;
 };
@@ -340,6 +340,11 @@ export interface FBQ {
 	// consent and LDU
 	(cmd: 'consent', state: 'grant' | 'revoke'): void;
 	(cmd: 'dataProcessingOptions', options: string[], countryCode?: number, stateCode?: number): void;
+
+	/** Prevent automatic listening to history.pushState/popstate */
+	disablePushState?: boolean;
+	/** Allow duplicate page view events (legacy / undocumented behavior) */
+	allowDuplicatePageViews?: boolean;
 }
 
 declare global {

src/lib/util/ip.ts

@@ -0,0 +1,20 @@
+/**
+ * Extracts the client's IP address from the request headers or falls back to a provided function.
+ *
+ * @param request - The incoming Request object.
+ * @param getClientAddress - A function that returns the client's IP address as a fallback.
+ * @returns The client's IP address as a string.
+ */
+export const getRequestIP = (request: Request, getClientAddress: () => string) => {
+	return (
+		request.headers.get('x-forwarded-for') ||
+		request.headers.get('cf-connecting-ip') ||
+		request.headers.get('x-real-ip') ||
+		request.headers.get('x-client-ip') ||
+		request.headers.get('x-cluster-client-ip') ||
+		request.headers.get('x-original-forwarded-for') ||
+		request.headers.get('forwarded-for') ||
+		request.headers.get('forwarded') ||
+		getClientAddress()
+	);
+};

src/lib/util/meta-pixel-loader.ts

@@ -1,4 +1,5 @@
 import { browser } from '$app/environment';
+import log from 'loglevel';
 
 const SCRIPT_SRC = 'https://connect.facebook.net/en_US/fbevents.js';
 
@@ -8,22 +9,60 @@ type QueuedFBQ = ((...args: unknown[]) => void) & {
 	loaded?: boolean;
 	version?: string;
 	push?: unknown;
+	disablePushState?: boolean;
+	allowDuplicatePageViews?: boolean;
 };
 
 /**
  * Loads the Meta Pixel script and configures the `fbq` function to queue
  * commands until the script is fully loaded. You may optionally await the
  * returned Promise to ensure the script has loaded before proceeding.
+ *
+ * Options:
+ * - `disablePushState` (default: true) — when true, sets
+ *   `window.fbq.disablePushState = true` before the pixel script loads so the
+ *   pixel does not auto-listen to `history.pushState`/`popstate` (recommended
+ *   for SPA frameworks like Svelte).
+ * - `allowDuplicatePageViews` (default: false) — when true, sets
+ *   `window.fbq.allowDuplicatePageViews = true` on the stub.
  */
-export const loadMetaPixel = (): Promise<void> => {
+export const loadMetaPixel = (opts?: {
+	disablePushState?: boolean;
+	allowDuplicatePageViews?: boolean;
+}): Promise<void> => {
 	// Make sure we're using the browser
 	if (!browser || !window) {
-		return Promise.reject(new Error('Window is undefined'));
+		return Promise.reject(new Error(`Not in browser, can't access window`));
 	}
 
+	// Default behavior: disable pushState handling since Svelte apps manage
+	// navigation themselves and Meta's auto-patching of history APIs can
+	// cause duplicate/incorrect pageview events. Consumers can pass
+	// `opts.disablePushState = false` to opt out.
+	const disablePushState = opts?.disablePushState ?? true;
+	const allowDuplicatePageViews = opts?.allowDuplicatePageViews ?? false;
+
 	// If fbq is already defined, resolve immediately
 	const existing = window.fbq as QueuedFBQ | undefined;
-	if (existing && existing.loaded) {
+	if (existing) {
+		// If the existing stub is present but hasn't set these flags yet, set
+		// them now so the loaded library (if it inspects them) sees intended
+		// behavior. Setting these is a no-op if initialization already
+		// completed.
+		if (disablePushState) existing.disablePushState = true;
+		if (allowDuplicatePageViews) existing.allowDuplicatePageViews = true;
+		const existingScript = getExistingScript();
+		if (existingScript) {
+			return new Promise((resolve, reject) => {
+				attachToScript(existingScript, resolve, reject);
+			});
+		}
+
+		log.debug(
+			'Meta Pixel fbq already present, skipping injection',
+			existing.version,
+			existing.queue
+		);
 		return Promise.resolve();
 	}
 
@@ -40,18 +79,18 @@ export const loadMetaPixel = (): Promise<void> => {
 	q.push = q;
 	q.loaded = true;
 	q.version = '2.0';
+	// set control flags on the stub before the meta script runs
+	if (disablePushState) q.disablePushState = true;
+	if (allowDuplicatePageViews) q.allowDuplicatePageViews = true;
 	window.fbq = q;
+	window._fbq = q;
 
 	return new Promise((resolve, reject) => {
 		// Avoid adding the same script twice
-		const existingScript = document.querySelector(
-			`script[src="${SCRIPT_SRC}"]`
-		) as HTMLScriptElement | null;
+		const existingScript = getExistingScript();
 		if (existingScript) {
-			existingScript.addEventListener('load', () => resolve());
-			existingScript.addEventListener('error', () =>
-				reject(new Error('Failed to load Meta Pixel script'))
-			);
+			attachToScript(existingScript, resolve, reject);
+			log.debug('Meta Pixel script already present, waiting for load');
 			return;
 		}
 
@@ -59,8 +98,23 @@ export const loadMetaPixel = (): Promise<void> => {
 		const script = document.createElement('script');
 		script.src = SCRIPT_SRC;
 		script.async = true;
-		script.addEventListener('load', () => resolve());
-		script.addEventListener('error', () => reject(new Error('Failed to load Meta Pixel script')));
+		attachToScript(script, resolve, reject);
 		document.head.appendChild(script);
+		log.debug('Meta Pixel script added to document');
 	});
 };
+
+const getExistingScript = (): HTMLScriptElement | null => {
+	return document.querySelector(
+		`script[src*="connect.facebook.net"][src*="fbevents.js"]`
+	) as HTMLScriptElement | null;
+};
+
+const attachToScript = (
+	el: HTMLScriptElement,
+	resolve: () => void,
+	reject: (err: Error) => void
+) => {
+	el.addEventListener('load', () => resolve());
+	el.addEventListener('error', () => reject(new Error('Failed to load Meta Pixel script')));
+};