API Reference

⚙️Metrics API Reference

Built-in Prometheus metrics for request count, duration histograms, and memory usage. Exposed at `/metrics` endpoint.

Overview#

Built-in Prometheus metrics for request count, duration histograms, and memory usage. Exposed at /metrics endpoint.

php

use Siro\Core\Metrics;

Setup#

php

// In routes/api.php (auto-enabled)
Metrics::init('siro', true);
Metrics::registerRoute($app->router);

// Now GET /metrics returns Prometheus-formatted data

Metrics Collected#

Metric	Type	Labels	Description
`http_requests_total`	Counter	`method`, `path`, `status`	Total request count
`http_request_duration_ms`	Histogram	`method`, `path`	Request duration buckets
`http_request_memory_mb`	Histogram	`method`	Memory usage per request

Custom Metrics#

php

// Counter
Metrics::counter(
    name: 'orders_created_total',
    value: 1,
    labels: ['status' => 'pending'],
    help: 'Total orders created',
);

// Histogram
Metrics::histogram(
    name: 'payment_processing_ms',
    value: 153.2,
    labels: ['gateway' => 'stripe'],
    help: 'Payment processing time',
    buckets: [50, 100, 200, 500, 1000],
);

// Gauge (current value, not cumulative)
Metrics::gauge(
    name: 'active_users',
    value: 42,
    labels: ['plan' => 'premium'],
    help: 'Currently active users',
);

Export Format (OpenMetrics)#

# HELP http_requests_total Total request count
# TYPE http_requests_total counter
http_requests_total{method="GET",path="/api/products",status="200"} 1542 1712345678

# HELP http_request_duration_ms Request duration in milliseconds
# TYPE http_request_duration_ms histogram
http_request_duration_ms_bucket{method="GET",path="/api/products",le="10"} 890
http_request_duration_ms_bucket{method="GET",path="/api/products",le="50"} 1420
http_request_duration_ms_bucket{method="GET",path="/api/products",le="+Inf"} 1542
http_request_duration_ms_sum{method="GET",path="/api/products"} 28450.5
http_request_duration_ms_count{method="GET",path="/api/products"} 1542

Available Methods#

Method	Description
`init(string $namespace, bool $persist)`	Initialize metrics system
`counter(string $name, int $value, array $labels, string $help)`	Increment counter
`histogram(string $name, float $value, array $labels, string $help, array $buckets)`	Record observation
`export()`	Get OpenMetrics text
`registerRoute(Router $router, string $path)`	Auto-register `/metrics` endpoint
`persistNow()`	Flush to cache immediately