Developer reference

The Monitor is 17 files of GPL PHP with a deliberately small public surface. Everything below is the supported integration contract.

Filters

aismon_cost_rates

The model price table. Keys are lowercase model-id prefixes (longest match wins); values are [input, output] in USD per 1M tokens.

add_filter( 'aismon_cost_rates', function ( $rates ) {
    // Your contracted rate for GPT-4o.
    $rates['gpt-4o'] = array( 2.00, 8.00 );
    // A model missing from the bundled table.
    $rates['grok-3'] = array( 3.00, 15.00 );
    return $rates;
} );

Unknown models record tokens but show ”—” for cost.

aismon_retention_days

Retention window for recorded calls (default 90, minimum 7). A daily cron prunes older rows.

add_filter( 'aismon_retention_days', fn() => 30 );

Actions

aismon_usage_recorded

Fires after each call is stored. Receives the stored row (array $data, column => value) and the row id. This is the integration point AI Spend Governance uses; it’s stable API.

aismon_dashboard_after_summary

Fires after the dashboard summary cards, with $totals and $period. Render extra panels here (Governance injects its budget card this way).

Database

One table: {$wpdb->prefix}aismon_usage, indexed on created_at, source_slug, and status.

Column	Notes
created_at	UTC datetime
status	completed or blocked (blocked rows are written by Governance)
source_type / source_slug / source_name	plugin, theme, or core attribution
provider / model / capability	from the AI Client’s result metadata
prompt_tokens / completion_tokens / total_tokens	total = prompt + completion
est_cost_usd	NULL when the model has no rate

Uninstalling drops the table and all options/transients.

How attribution works

The recorder listens to the AI Client’s wp_ai_client_after_generate_result lifecycle hook and walks the backtrace to the first file inside a plugin or theme directory — the same technique Query Monitor uses. Calls from WP-Cron attribute to the plugin whose callback ran; calls from WP-CLI or custom code outside plugins attribute as core.

CSV export format

One row per call, columns matching the table above, formula-injection-safe quoting, capped at 50,000 rows per export.

What there is no API for

Recording is automatic and can’t be triggered manually; there is intentionally no public write API into the usage table beyond the recorder itself (Governance’s blocked-row logging is the one internal exception).