> ## Documentation Index
> Fetch the complete documentation index at: https://docs.senderz.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Meta audiences

> Sync a Senderz segment 1:1 to a Meta Custom Audience — outbound only.

Connect Meta to keep a Custom Audience in lockstep with a Senderz segment: whoever enters the segment joins the audience, whoever leaves is removed.

<Info>
  This is **outbound only**. There are no inbound events from Meta — Senderz
  pushes membership, it never reads back.
</Info>

## How it works

<Steps>
  <Step title="Connect Meta">
    Authorise Senderz to manage your Custom Audiences.
  </Step>

  <Step title="Link a segment">
    Map a Senderz segment to a Meta Custom Audience — a 1:1 connection.
  </Step>

  <Step title="Continuous sync">
    On a schedule, Senderz diffs the segment against the last-synced snapshot
    and applies only the changes (joins and removes).
  </Step>
</Steps>

## Identity & hashing

Members are matched on hashed email and phone. **Normalisation is provider-specific** — Meta's rules differ from Google's, so Senderz normalises per provider before hashing. Feeding one provider the other's normalisation produces a valid hash that matches nobody.

<Warning>
  Ad-audience matching depends on correct per-provider normalisation. Senderz
  handles this internally — the point is that email/phone must be normalised
  Meta's way before the SHA-256, which the connector does for you.
</Warning>

## Shared foundation with Google

Meta and Google Customer Match share provider-agnostic tables and the same membership-diff engine. The two connectors reuse that foundation rather than forking separate models.

<Note>
  The Meta connector is in progress. See
  [Google Customer Match](/en/integrations/google-customer-match) for the
  sibling ad-sync integration.
</Note>