Goal

Bootstrap a sibling plugin only when:

1. mam-main is installed and active
2. mam-main is at the required version
3. The customer is entitled to use this plugin

Background

mam-main exposes two filters for sibling-plugin gating:

• mam_check_required_version — checks whether a plugin is at a sufficient version
• mam_plugin_entitlement — checks the WPMAM entitlement record for a plugin slug

A well-behaved sibling plugin checks both before bootstrapping its hooks. A poorly-behaved one bootstraps unconditionally and produces fatal errors when mam-main isn’t loaded — or worse, runs on un-entitled customer sites.

Steps

1. Wrap your bootstrap in a plugins_loaded callback at priority 11

mam-main runs its register_*() chain on its own constructor (called early). By priority 11 on plugins_loaded, mam-main’s hooks are registered and its filters are answerable.

add_action( 'plugins_loaded', 'mam_my_plugin_bootstrap', 11 );

2. Check the required version

function mam_my_plugin_bootstrap() {

    $required_version = '1.9.1';
    $mam_version      = apply_filters( 'mam_check_required_version', $required_version, 'MAM My Plugin' );

    if ( version_compare( $mam_version, $required_version, '<' ) ) {
        // mam-main is too old (or missing).
        add_action( 'admin_notices', 'mam_my_plugin_required_version_notice' );
        return;
    }

    // ... continue
}

The filter takes two args — the required version and a plugin label — and returns the installed mam-main version string (it also logs an admin alert when the installed version is below the requirement). Compare the returned version yourself with version_compare(); it does not return a boolean.

3. Check entitlement

function mam_my_plugin_bootstrap() {

    // ...required version check...

    $entitlement = apply_filters( 'mam_plugin_entitlement', null, 'mam-my-plugin' );
    $state       = is_array( $entitlement ) ? ( $entitlement['state'] ?? '' ) : '';

    if ( 'blocked' === $state ) {
        // Not purchased, or entitlement revoked — silently skip.
        return;
    }

    if ( 'expired' === $state ) {
        // Past expiry — show admin notice but don't bootstrap.
        add_action( 'admin_notices', 'mam_my_plugin_expired_notice' );
        return;
    }

    // state is 'entitled' or 'grace' → bootstrap functional code
}

The filter always returns an array with a state key — one of entitled, grace, blocked, or expired (plus reason, plugin_slug, and expires_at for grace/expired). It never returns a bare false, so gate on the state value, not on truthiness. Cache misses and unreachable WPMAM fail open (returned as entitled).

4. Bootstrap your plugin

function mam_my_plugin_bootstrap() {
    // ...gate checks...

    // OK to bootstrap.
    new MAM_My_Plugin_Manager();
}

Common admin-notice patterns

function mam_my_plugin_required_version_notice() {
    echo '<div class="notice notice-warning"><p>';
    echo 'MAM My Plugin requires MAM Main version 1.9.1 or later.';
    echo '</p></div>';
}

function mam_my_plugin_expired_notice() {
    echo '<div class="notice notice-error"><p>';
    echo 'MAM My Plugin entitlement has expired. Contact support to renew.';
    echo '</p></div>';
}

Show notices only on admin pages where they’re useful — guard with is_admin() and screen checks if needed.

Caching the gate decision

The entitlement filter is cached on the mam_entitlement_manager side, so calling it once on bootstrap is fine. Don’t re-check on every request:

// Good — bootstrap-time check, cached for the session
function mam_my_plugin_bootstrap() {
    $entitlement = apply_filters( 'mam_plugin_entitlement', null, 'mam-my-plugin' );
    if ( 'blocked' === ( $entitlement['state'] ?? '' ) ) return;
    // ...
}

// Bad — checking on every request
add_filter( 'some_hook', function ( $value ) {
    $entitlement = apply_filters( 'mam_plugin_entitlement', null, 'mam-my-plugin' );  // ← redundant
    if ( 'blocked' === ( $entitlement['state'] ?? '' ) ) return $value;
    // ...
} );

What “entitled” means

The entitlement record is per-customer-site and per-plugin. A site might have:

• Some plugins entitled, others not
• A plugin entitled at one tier (basic) but not another (premium)
• An entitlement that expires and renews via WPMAM
• An entitlement that’s been blocked by support

Your plugin should respect the record’s state field (entitled, grace, blocked, expired) and adapt accordingly.

Gotchas

• Priority 11 on plugins_loaded. Not 10 — at priority 10, mam-main’s register_*() chain hasn’t necessarily completed.
• Don’t bootstrap on file include. Wait for plugins_loaded so mam-main is loaded.
• Entitlement can change at runtime. A plugin that bootstraps once per request and caches the gate decision in PHP memory will not pick up a same-request entitlement change. Acceptable for most cases; if your plugin needs to react to revocation, use a longer-running mechanism (cron + invalidation).
• WPMAM unreachability can produce stale entitlement reads. The graceful-degradation hook (mam_account_code_verify_fallback-style) typically defaults to “still entitled” during planned outages — confirm behavior with WPMAM ops.
• Don’t try to “auto-recover” from blocked entitlement. A blocked entitlement means contact support.

Related articles

• Extending mam-main: developer guide
• Integration: Account code and enrollment server
• Hook: mam_plugin_entitlement
• Frozen public contracts reference

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