# ReadMetrics.srv

## Overview

`ReadMetrics.srv` reads the current metrics from the Cartographer node. It returns metric families with their values as of the reported timestamp.

## Request

This service has an empty request.

## Response

| Field | Type | Description |
| --- | --- | --- |
| `status` | `cartographer_ros_msgs/StatusResponse` | The outcome of the request; check `code` against `StatusCode.OK`. |
| `metric_families` | `cartographer_ros_msgs/MetricFamily[]` | The metric families describing counters, gauges, and histograms. |
| `timestamp` | `builtin_interfaces/Time` | The time at which the metrics were captured. |

## Usage

- Consumers group metrics by `MetricFamily.name` and distinguish instances by their labels.
- The `timestamp` indicates how fresh the reported values are.