Key takeaways
- CAPI integration connects your first-party data to a platform's Conversions API, sending events server-side rather than from the browser.
- The pattern is the same across Meta, Snap, TikTok, LinkedIn, and Reddit, even though each platform's endpoint differs.
- Identifiers such as email and phone are hashed with SHA-256 before send, so platforms receive irreversible strings.
- A CAPI integration runs alongside the pixel, deduplicated on a shared event ID, not instead of it.
- You can build the integration directly, or use a managed connector that maintains it across platforms.
- It recovers and stabilises signal that already exists; it does not manufacture demand.
- Showmax went live on Meta Web CAPI in about 15 minutes, and Giving Movement saw a 15.8x ROAS increase on Snap's Conversions API.
What is CAPI integration?
CAPI integration is the work of wiring your conversion data into a platform’s Conversions API, the server-side interface most ad platforms now provide. A browser pixel measures actions client-side, where ad blockers, tracking prevention, and cookie limits suppress a share of events. A CAPI integration sends those events from your server, where the restrictions do not apply, so the platform receives a fuller record. The pattern is consistent across platforms: Meta for Developers, Snap Business Help, and the other platforms each document a Conversions API that takes hashed events server-side. Datahash keeps its first-party data and CAPI writing on the mechanics current across all of them.
How does a CAPI integration work?
A CAPI integration works by building each conversion event on your server and posting it to the platform with hashed identifiers attached. The steps run in order:
- A customer acts on your site, app, or in your CRM: a purchase, a lead, a subscription.
- Your server builds the event with a name, timestamp, value, and a unique event ID.
- It normalises and SHA-256 hashes the identifiers, such as email and phone, and attaches the platform’s click ID where present.
- It posts the event to that platform’s Conversions API endpoint.
- The platform matches the event to a person and deduplicates against the pixel on the shared event ID.
The only real difference between platforms is the endpoint and the exact fields each expects. The identifier discipline, normalise, hash, deduplicate, is the same everywhere, which is why a single first-party data layer can feed all of them.
Which platforms have a Conversions API to integrate?
Most major ad platforms now offer a Conversions API, so a CAPI integration is rarely a one-platform job. The table shows the common destinations and what each one is used for.
| Platform | Conversions API | Common use |
|---|---|---|
| Meta | Conversions API for web, app, offline, CRM | Recover web events, send offline and CRM outcomes |
| Snap | Conversions API for web and app | Server-side purchases and app events |
| TikTok | Events API for web, app, offline | Server-side conversions and combined online-offline |
| LinkedIn and Reddit | Conversions API for leads and web | B2B lead and web conversion signal |
Datahash exposes these as ready connections, including Meta’s server-side integrations, Snap’s Conversions API integrations, and LinkedIn’s server-side integrations, so the same event flow reaches each platform without a separate build per destination.
How do you set up a CAPI integration?
Setting up a CAPI integration is the same shape on every platform once you decide how to build it. The steps run in order:
- Choose the build: a direct server-side integration, or a managed connector that maintains it for you.
- Identify the events that matter and map them to the platform’s standard events.
- Normalise and hash the identifiers, and attach a shared event ID for deduplication with the pixel.
- Connect to each platform’s Conversions API endpoint and send the events.
- Verify delivery and deduplication in each platform’s events tool before scaling spend.
What are the benefits of a CAPI integration?
The benefits of a CAPI integration all come from giving each platform a more complete and reliable record of your conversions. The main ones are:
- Recovered events: conversions the browser pixel loses to blockers and cookie limits still reach the platform from your server.
- Better attribution: more matched conversions mean campaigns are credited accurately, so you see which ones truly drive revenue.
- Stronger optimisation: automated bidding and lookalikes learn from a fuller set of real conversions, not a suppressed sample.
- Offline and CRM reach: a CAPI integration can carry sales that close off-site, which the pixel never sees at all.
- One data layer across platforms: the same event flow feeds Meta, Snap, TikTok, and more, so you build once rather than per platform.
The gains are largest for accounts that were losing the most signal to browser restrictions, because a CAPI integration recovers exactly the events those restrictions were suppressing. It does not add demand, but it stops you paying to generate conversions the platform then fails to see.
Manual build or managed connector: which for a CAPI integration?
The choice in a CAPI integration is between building it yourself and using a managed connector, and it turns on engineering capacity more than anything else. A manual build gives full control of the payload and routing, which suits teams with unusual events and in-house engineers, but every platform endpoint is then yours to maintain as it changes. A managed connector stands the integration up quickly, handles the hashing and deduplication, and keeps current with each platform for you, at the cost of a dependency on the provider. For most businesses running several platforms, the maintenance burden of a manual multi-platform build is the deciding factor, because each Conversions API evolves on its own schedule and a stale integration silently drops events. The connector route trades a little control for not having to notice, and fix, those changes yourself.
What are the limits of CAPI integration?
A CAPI integration improves how reliably events reach a platform; it does not create events that never happened. If customers do not convert, there is nothing to send, and server-side plumbing cannot rescue a weak funnel. Match quality still depends on the identifiers you hold, so events with no email, phone, or click ID match poorly. Running it without deduplication double-counts, which corrupts both reporting and optimisation. And maintaining a direct integration across several platforms is real, ongoing engineering, because each endpoint changes on its own schedule. A CAPI integration recovers and stabilises signal that already exists. Across platforms, keeping it alive is the work most teams underestimate.
What Datahash does about this
Datahash runs CAPI integration as managed infrastructure across Meta, Snap, TikTok, Google, LinkedIn, and Reddit from one first-party data layer. It hashes identifiers server-side, populates each event with the match keys that lift attribution, and configures deduplication against every platform’s pixel, so one setup covers destinations that would otherwise be separate builds. Because the hashing happens before anything leaves your systems, the flow stays consistent with GDPR and DPDP. Showmax went live on Meta Web CAPI in about 15 minutes, and Giving Movement recorded a 15.8x ROAS increase on Snap’s Conversions API, each attributed to its own platform and scope. The Showmax integration is documented as a case study, and delivery is visible per connection, so the integration is measured rather than assumed.