Pixelflow
Meta Event Parameters

Required Meta Events Parameters

When sending events to Meta through PixelFlow, certain parameters must always be included to ensure proper delivery and attribution. PixelFlow handles all required parameters automatically—you never need to worry about missing data in Facebook Ads Manager.

Required Parameters for Every Event

Meta requires these four parameters on every event sent via Conversions API. PixelFlow captures and sends all of them automatically:

1. event_name

  • Defines the type of event you are sending.

  • Examples: Purchase, Lead, AddToCart, PageView.

  • Meta uses the event name to understand what action took place and to group it with other similar events for reporting and optimization.

2. event_time

  • The exact time the event occurred, represented as a Unix timestamp in seconds.

  • This ensures that events are logged in the correct order and aligned with ad interactions.

  • Without event_time, Meta cannot accurately attribute the event to an ad impression or click.

3. event_source_url

  • The URL where the event took place.

  • This gives context about the source of the action and allows you to see which pages are driving conversions.

  • It also helps with reporting inside Meta Events Manager.

4. action_source

  • Describes where the event originated.

  • Common values include:

    • website (events from your website)

    • app (events from your mobile app)

    • phone_call (events from a call center or phone order)

    • chat (events from messaging platforms)

  • PixelFlow automatically sets this to website for all web events.

Parameters PixelFlow Collects Automatically

Beyond the four required parameters, PixelFlow automatically captures additional data on every event to improve event match quality and attribution. You don't need to configure anything—these are collected by default:

User Identification Parameters

fbp (Facebook Browser ID)

  • A cookie that uniquely identifies the browser

  • Automatically set when someone visits your site

  • Critical for matching events to Meta accounts

fbc (Facebook Click ID)

  • Automatically captured when someone clicks a Facebook ad

  • Provides direct attribution from ad click to conversion

  • Increases event match quality by +1.5 points

Network and Device Parameters

client_ip_address

  • The user's IP address

  • Captured automatically from every visitor

  • Used for geographic location derivation and event matching

client_user_agent

  • Browser and device information from the user's request

  • Includes browser type, version, operating system, and device details

  • Helps Meta understand the environment where the event occurred

Geographic Parameters

PixelFlow automatically derives these from the user's IP address:

  • Country: The user's country

  • State: The user's state or region

  • City: The user's city

These geographic parameters provide location context for better ad targeting and reporting.

What about zip code? PixelFlow does not automatically capture zip code data. If you need zip code for specific use cases, you can collect it through form fields and send it as a custom parameter.

Deduplication Parameters

event_id

  • A unique identifier generated for each event

  • Ensures the same event isn't counted twice when sent from both browser and server

  • PixelFlow automatically generates and manages event IDs for deduplication

Base Event Match Quality Score

These automatically collected parameters provide a baseline Event Match Quality (EMQ) score of 5.2 out of 10 before any user data is added. This includes:

  • fbp (Facebook Browser ID)

  • IP address

  • User agent

  • Geographic data (country, state, city)

This is why PageView events—which happen before you collect user information—typically score around 5-6/10. When you add user data like email and phone through form tracking, conversion events can reach 8-9.5/10.

Pro tip: To maximize event match quality for conversion events like Lead and Purchase, configure form tracking to capture email and phone. These parameters can boost your score from 5.2 to 9.5/10. Learn more in Recommended User Data Parameters.

Why These Parameters Matter

Each parameter serves a specific purpose in event delivery and optimization:

  • Accuracy: event_time ensures conversions are matched to the right ads.

  • Context: event_source_url and action_source show Meta where and how the event happened.

  • Classification: event_name tells Meta what type of action to record.

  • Attribution: IP, user agent, geographic data, and browser IDs help Meta match events to specific users and ad interactions.

  • Deduplication: event_id prevents double-counting when using both Pixel and CAPI.

Together, these parameters form the foundation of every event you send to Meta. PixelFlow handles them all automatically, guaranteeing that your data flows correctly into Meta Events Manager.

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