improve logs & capi event source URL handling

src/lib/capi/event.ts

@@ -1,6 +1,7 @@
 import type { StandardEventName } from '../types/fbq.js';
 import * as v from 'valibot';
 import crypto from 'node:crypto';
+import log from 'loglevel';
 
 const sha256 = (value: string): string => {
 	return crypto.createHash('sha256').update(value).digest('hex');
@@ -202,7 +203,11 @@ export type CAPIEventOptions = {
 	eventTime?: Date;
 	userData: CAPICustomerInfoParams;
 	customData?: CAPIStandardParams;
-	/** Required if actionSource is set to 'website' */
+	/**
+	 * Required by Meta if actionSource is set to 'website'. If not provided and
+	 * actionSource is 'website', a warning will be emitted and the field may be
+	 * filled by the server receiving the event, however, accuracy is not guaranteed.
+	 */
 	eventSourceURL?: string;
 	optOut?: boolean;
 	eventID?: string;
@@ -220,6 +225,12 @@ export class CAPIEvent {
 		return this._params;
 	}
 
+	/** Returns human-readable event name, optionally including event ID. */
+	get readableName() {
+		if (!this._params) return 'Unknown Event';
+		return `${this._params.event_name}${this._params.event_id ? ` (${this._params.event_id})` : ''}`;
+	}
+
 	private constructor() {}
 
 	/**
@@ -249,9 +260,28 @@ export class CAPIEvent {
 		};
 
 		event._params = v.parse(MetaServerEventParamsSchema, event._params);
+		event.paramIntegrationCheck();
 		return event;
 	}
 
+	/**
+	 * Performs integration checks on the event parameters and logs warnings
+	 * if potential issues are detected.
+	 */
+	private paramIntegrationCheck() {
+		if (
+			this._params &&
+			this._params.action_source === ActionSource.Website &&
+			!this._params.event_source_url
+		) {
+			console.warn(
+				`[CAPIEvent] Warning: ${this.readableName} ` +
+					`with actionSource 'website' is missing eventSourceURL. Provide eventSourceURL to improve ` +
+					`data quality and avoid blocks by Meta.`
+			);
+		}
+	}
+
 	/**
 	 * Unmashals a JSON string or object into a CAPIEvent instance and parses
 	 * its parameters to match Meta's expected shape.
@@ -265,6 +295,7 @@ export class CAPIEvent {
 		const parsed = v.parse(MetaServerEventParamsSchema, obj);
 		const event = new CAPIEvent();
 		event._params = parsed;
+		event.paramIntegrationCheck();
 		return event;
 	}
 
@@ -309,7 +340,8 @@ export class CAPIEvent {
 	}
 
 	/**
-	 * Enriches the CAPIEvent with additional user data.
+	 * Enriches the CAPIEvent with additional user data. Will not override
+	 * existing user data fields if already set.
 	 * @param additionalData - Additional user data to merge.
 	 * @throws Will throw an error if the enriched data fails validation.
 	 */
@@ -326,4 +358,25 @@ export class CAPIEvent {
 		// Re-validate after enrichment
 		this._params = v.parse(MetaServerEventParamsSchema, this._params);
 	}
+
+	/**
+	 * Enriches the CAPIEvent with an event source URL. Will not override
+	 * existing event source URL if already set AND will only apply if the
+	 * action source is 'website'. A message will be logged to warn the user
+	 * that an implicit event source URL is being set.
+	 * @param url - The event source URL to set.
+	 */
+	unsafeEventSourceURL(url?: string) {
+		if (!this._params) return;
+		if (!url) {
+			log.warn(
+				`[CAPIEvent] ${this.readableName} could not implicitly set eventSourceURL, event will be submitted without it.`
+			);
+			return;
+		}
+		if (!this._params.event_source_url && this._params.action_source === ActionSource.Website) {
+			this._params.event_source_url = url;
+			log.warn(`[CAPIEvent] ${this.readableName} implicitly setting eventSourceURL to ${url}`);
+		}
+	}
 }

src/lib/capi/handle.ts

@@ -45,6 +45,7 @@ export const createCAPIHandler: (connector: CAPIConnector) => RequestHandler = (
 			const ip = getRequestIP(request, getClientAddress);
 			const ua = request.headers.get('user-agent') ?? undefined;
 			const { fbp, fbc } = getFbpFbcFromCookies(cookies);
+			const eventSourceURL = request.headers.get('referer') ?? undefined;
 
 			const enrichedUserData: Partial<CAPICustomerInfoParams> = {
 				clientIP: ip,
@@ -53,10 +54,11 @@ export const createCAPIHandler: (connector: CAPIConnector) => RequestHandler = (
 				fbc
 			};
 
-			// Enrich each event's user data
+			// Enrich each event's user data & event source URL
 			const events: CAPIEvent[] = parsed.events.map((eventParams) => {
 				const event = CAPIEvent.fromObject(eventParams);
 				event.enrichUserData(enrichedUserData);
+				event.unsafeEventSourceURL(eventSourceURL);
 				return event;
 			});
 

src/lib/metapixel/pixel-control.ts

@@ -12,7 +12,12 @@ import { resolveGetter, type MaybeGetter } from '../util/getter.ts';
 import log from 'loglevel';
 import { dev } from '$app/environment';
 import { CAPIClient } from '../capi/client.ts';
-import { ActionSource, CAPIEvent, type CAPIStandardParams } from '../capi/event.ts';
+import {
+	ActionSource,
+	CAPIEvent,
+	type CAPIEventOptions,
+	type CAPIStandardParams
+} from '../capi/event.ts';
 
 const pixelParamsToCustomData = (params: CommonParams & CustomParams): CAPIStandardParams => {
 	const customData: CAPIStandardParams = {};
@@ -101,7 +106,7 @@ export class PixelControl {
 			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.`
+				`${this.logPrefix} CAPI Client ${options.conversionHref} available but not initialized, TrackingManager is required for user consent.`
 			);
 		}
 	}
@@ -150,7 +155,7 @@ export class PixelControl {
 		// Check for existing PixelControl instance
 		if (this._registeredPixels[pixelID]) {
 			log.warn(
-				`[PixelControl] Instance for Meta Pixel ID: ${pixelID} already exists. Returning existing instance.`
+				`${this._registeredPixels[pixelID].logPrefix} Instance already exists. Returning existing instance.`
 			);
 			return this._registeredPixels[pixelID];
 		}
@@ -161,7 +166,7 @@ export class PixelControl {
 
 		// Fire initialization
 		window.fbq('init', pixel._pixelID, options?.advancedMatching, options?.initOptions);
-		log.debug(`[PixelControl] [${pixel._pixelID}] initialized.`);
+		log.debug(`${pixel.logPrefix} initialized.`);
 
 		return pixel;
 	}
@@ -196,12 +201,17 @@ export class PixelControl {
 	private devModeWarn() {
 		if (dev && !this._testEventCode) {
 			log.warn(
-				`[PixelControl] [${this._pixelID}] Sending events in dev mode without a test event code. ` +
+				`${this.logPrefix} Sending events in dev mode without a test event code. ` +
 					'Consider providing a test event code to avoid affecting real data.'
 			);
 		}
 	}
 
+	/** Returns the log prefix including the pixel ID */
+	private get logPrefix(): string {
+		return `[PixelControl] [${this._pixelID}]`;
+	}
+
 	/**
 	 * Shorthand utility to send a PageView event
 	 * @param disableCAPI If true, disables sending this event to the Conversion API
@@ -230,22 +240,28 @@ export class PixelControl {
 			eventID = crypto.randomUUID();
 		}
 
-		this._conversionClient
+		const opts: CAPIEventOptions = {
-			.trackEvent(
-				CAPIEvent.fromOpts({
 			eventName: event,
 			eventID: eventID,
 			actionSource: ActionSource.Website,
+			eventSourceURL: window.location.href,
 			eventTime: new Date(),
 			userData: {
 				clientUserAgent: navigator.userAgent
 			},
 			customData: params ? pixelParamsToCustomData(params) : undefined
-				})
+		};
-			)
+		const ev = CAPIEvent.fromOpts(opts);
+
+		log.debug(
+			`${this.logPrefix} ${ev.readableName} forwarding to CAPI with body: ${JSON.stringify(ev.params, null, 2)}`
+		);
+
+		this._conversionClient
+			.trackEvent(ev)
 			.then((response) => {
 				log.debug(
-					`[PixelControl] [${this._pixelID}] ${event} event forwarded to Conversion API with Event ID: ${eventID}, Response: ${JSON.stringify(
+					`${this.logPrefix} ${ev.readableName} forwarded to CAPI, response: ${JSON.stringify(
 						response,
 						null,
 						2
@@ -253,15 +269,22 @@ export class PixelControl {
 				);
 			})
 			.catch((error) => {
-				log.error(
+				log.error(`${this.logPrefix} ${ev.readableName} failed to forward to CAPI. Error: `, error);
-					`[PixelControl] [${this._pixelID}] Failed to forward ${event} event to Conversion API with Event ID: ${eventID}`,
-					error
-				);
 			});
 
 		return eventID;
 	}
 
+	private getEventReadableName(
+		event: StandardEventName | string,
+		eventID?: string,
+		testCode?: string
+	): string {
+		return (
+			event + (eventID ? ` (${eventID})` : '') + (testCode ? ` [test_event_code: ${testCode}]` : '')
+		);
+	}
+
 	/**
 	 * Tracks a standard event for this pixel (uses `trackSingle` under the hood)
 	 * @param event Standard event name
@@ -290,7 +313,7 @@ export class PixelControl {
 			test_event_code: this._testEventCode
 		});
 		log.debug(
-			`[PixelControl] [${this._pixelID}] ${event} event sent with event ID ${eventID} ${dev && ` (test code: ${this._testEventCode})`}.`
+			`${this.logPrefix} ${this.getEventReadableName(event, eventID, this._testEventCode)} sent.`
 		);
 	}
 
@@ -322,7 +345,7 @@ export class PixelControl {
 			test_event_code: this._testEventCode
 		});
 		log.debug(
-			`[PixelControl] [${this._pixelID}] ${event} custom event sent with event ID ${eventID} ${dev && ` (test code: ${this._testEventCode})`}.`
+			`${this.logPrefix} ${this.getEventReadableName(event, eventID, this._testEventCode)} sent.`
 		);
 	}
 }