Overview

Meta Web Conversions API (Web CAPI) enables Branch to forward web conversion events to Meta's Conversions API server-side. When users select your Meta ads that link to a Branch Ad Link, Branch captures click metadata, attributes the resulting web conversions, and forwards those events to Meta. This connects ad clicks, attribution, and campaign optimization.

Branch has always attributed web conversions. With Meta Web CAPI enabled, Branch also shares that web conversion signal with Meta. This gives Meta's algorithm the data it needs to improve Event Match Quality (EMQ) and optimize ad delivery. Meta Events Manager then shows more complete conversion reporting without relying solely on browser-based pixel tracking.

For more information about integrating ad partners in general, visit our Ad Partner Integration Guide.

Note: Meta Web CAPI vs. Meta SAN attribution

Meta Web CAPI sends web conversion signal from Branch to Meta to support optimization and reporting. It's separate from the Meta self-attributing network (SAN) integration, which returns app attribution claim data to Branch. Enabling Meta Web CAPI doesn't change how Branch attributes conversions or how Branch assigns Meta SAN credit.

Partner capabilities

Capability	Details
Supported event sources	Branch Web SDK, Server-to-server (S2S)
Platforms	Web
Event Match Quality (EMQ)	Supported, and enhanced when fbc is present
Event deduplication	Supported via event_id (mapped from event_data.transaction_id)

Before you begin

To set up Meta Web CAPI, you first need to:

• Enable Branch's Performance Product for your Branch account. Contact your Branch account manager or speak with our Sales team.
• Enable the Meta (Facebook) integration in Branch under Configuration > Integrations > Ad partners.
• Implement the Branch Web SDK on your website with event tracking configured, or send web conversion events through server-to-server (S2S) ingestion.
• Place Branch Ad Links in your Meta web campaigns. This is a primary matching signal Branch uses when forwarding events to Meta CAPI, and it improves EMQ. For more information, see Event Match Quality (EMQ).

Enable Meta Web CAPI

To begin, navigate to Configuration > Integrations in Branch, select the Ad partners tab, and use the Search partners bar to find Facebook.

Meta CAPI requires a Dataset ID and CAPI Access Token from your Meta Events Manager account. Follow the steps below to retrieve these credentials and enable CAPI forwarding in Branch.

Step 1: Retrieve your Dataset ID

1. Log in to Meta Events Manager.
2. Navigate to Datasets.
3. Select your dataset (pixel) from the left panel.
4. Copy your Dataset ID from the Events Activities window.

Step 2: Generate a CAPI access token

1. In Meta Events Manager, select the dataset from Step 1.
2. Select the Settings tab.
3. Under Conversions API, locate the Access Token section.
4. Select Generate access token.
5. Copy the token.

Step 3: Enter credentials in Branch

1. On the Facebook page in Branch, select Partner settings.
2. Under Postback Credentials, enter the Dataset ID from Step 1 in the Dataset ID field.
3. Enter the token from Step 2 in the CAPI Access Token field.
4. Select Save.

Once saved, Branch begins forwarding eligible web conversion events to Meta CAPI based on your configuration.

Configure postbacks

Branch forwards web conversion events to Meta CAPI based on your postback configuration. Branch maps these to Meta's standard Conversions API event names as follows:

Meta event	Branch event
Purchase	PURCHASE
AddToCart	ADD_TO_CART
ViewContent	VIEW_ITEM
InitiateCheckout	INITIATE_PURCHASE
CompleteRegistration	COMPLETE_REGISTRATION
Search	SEARCH
AddToWishlist	ADD_TO_WISHLIST
Subscribe	SUBSCRIBE
StartTrial	START_TRIAL
{custom_event_name}	{custom_event_name}

To forward all web conversion events Branch receives, not just events attributed to Meta campaigns, turn on Send all events on the Postback config tab, and then select Save Changes. This gives Meta the broadest possible signal for optimization and reporting.

To add postbacks for additional events or to customize behavior, follow the steps in the "Configure postbacks" section in the general Ad Partner Integration Guide.

Deduplicate events with Meta Pixel

If you also use the Meta Pixel or send events through CAPI from other sources, the same conversion event may reach Meta more than once. Meta deduplicates these events using a shared event_id. If both events carry the same event_name and event_id, Meta counts them as a single conversion.

Branch uses transaction_id as the event_id it sends to Meta CAPI. To enable deduplication, pass the same transaction_id in your Branch Web SDK event as you do for the eventID in your Meta Pixel event for the same conversion.

Caution: transaction_id required for deduplication

If you don't provide a transaction_id on the event, Branch omits event_id from the CAPI payload. Meta can't deduplicate those events with Pixel, which may result in duplicate conversions in Meta reporting.

Verify your data

After you save your credentials and configure postbacks, verify that events flow correctly:

• In Liveview: Confirm that web conversion events from your site appear in real time. Filter for Platform = Web to isolate web events.
• In Meta Events Manager: Navigate to your dataset and confirm that events forwarded by Branch appear under the Overview tab.
• In Meta Events Manager > Test Events: Use the Test Events tool to send a test conversion and verify that Meta receives and matches it correctly.

CAPI data mappings

Branch maps the following fields from web conversion events to the Meta Conversions API payload:

Meta CAPI field	Branch source field	Notes
event_name	name	Mapped to Meta standard event names. See Configure postbacks.
event_time	event_timestamp	Unix timestamp in seconds.
event_id	event_data.transaction_id	Used for event deduplication. Omitted if transaction_id isn't present on the event.
action_source	Hardcoded: "website"	Required by Meta for all web CAPI events.
event_source_url	user_data_http_origin	The URL of the page where the conversion occurred.
user_data.client_ip_address	user_data_ip	Captured from the originating web request.
user_data.client_user_agent	user_data_user_agent	Captured from the originating web request.
user_data.fbc	&fbclid (via Branch Ad Link)	Formatted as fb.1.{create_timestamp}.{fbclid}. Omitted if fbclid isn't present.
custom_data.value	revenue	Included when present on the event.
custom_data.currency	currency	Included when present on the event.
custom_data.contents	content_items[]	Maps $sku, $quantity, and $price from each content item.
custom_data.content_ids	content_items[].$sku	Array of $sku extracted from content items.

Map content type to product

Branch automatically sets content_type to product when the event carries content_items[]. Otherwise, Branch doesn't add the content_type parameter.

Troubleshoot

Use the checks below to troubleshoot common issues with Meta Web CAPI.

Events not appearing in Meta Events Manager

If forwarded events don't appear in Meta Events Manager, check the following:

• You entered your Dataset ID and CAPI Access Token correctly in Branch. An invalid token causes Meta to reject all events.
• Branch Liveview shows your web events, which means the Branch Web SDK or S2S is tracking them. Branch can only forward events it receives.
• Send all events is on in the Postback config tab, or your active postbacks include the specific events you expect.

Low EMQ score

If Meta reports a low EMQ score for forwarded events, check the following:

• Your Meta campaigns use Branch Ad Links. Without Branch Ad Links, Branch can't capture the fbc parameter, so CAPI events don't include it. The fbc parameter is the primary click-level matching signal and improves EMQ.
• Your Branch Web SDK implementation captures the page URL where conversions occur (event_source_url). Along with IP address and user agent, this field contributes to match quality when fbc is absent.

Duplicate conversions in Meta reporting

If you use both Meta Pixel and Branch CAPI and see higher-than-expected conversion counts in Meta reporting, deduplication may not be working. Check the following:

• The transaction_id in your Branch Web SDK event matches the eventID in your Meta Pixel event for the same conversion.
• Both the Pixel event and the CAPI event use the same event_name. Meta requires both the event name and the event ID to match for deduplication.