---
title: "App Starts Module"
url: https://develop.sentry.dev/sdk/telemetry/traces/modules/app-starts/
---

# App Starts Module

The App Starts module records metrics from spans in `ui.load` transactions using specific span operations.

# [Transaction Conventions](https://develop.sentry.dev/sdk/telemetry/traces/modules/app-starts.md#transaction-conventions)

## [Transaction Measurements](https://develop.sentry.dev/sdk/telemetry/traces/modules/app-starts.md#transaction-measurements)

| Key              | Unit         | Description                                                      | Conditions                   |
| ---------------- | ------------ | ---------------------------------------------------------------- | ---------------------------- |
| `app_start_cold` | milliseconds | The time it took to load the first frame during a cold app start | required for cold app starts |
| `app_start_warm` | milliseconds | The time it took to load the first frame during a warm app start | required for warm app starts |

# [Span Conventions](https://develop.sentry.dev/sdk/telemetry/traces/modules/app-starts.md#span-conventions)

## [Span Operations](https://develop.sentry.dev/sdk/telemetry/traces/modules/app-starts.md#span-operations)

| Span OP              | Description                          | Conditions                                                                           |
| -------------------- | ------------------------------------ | ------------------------------------------------------------------------------------ |
| `app.start.cold`     | An operation during cold start       | At least one span with the description "Cold Start" must be present in a transaction |
| `app.start.warm`     | An operation during warm start       | At least one span with the description "Warm Start" must be present in a transaction |
| `db.sql.query`       | A database query                     | -                                                                                    |
| `db.sql.transaction` | -                                    | -                                                                                    |
| `db`                 | An operation on the database         | -                                                                                    |
| `file.read`          | Reading a file from the file system  | -                                                                                    |
| `file.write`         | Writing to a file on the file system | -                                                                                    |
| `http.client`        | An outgoing network request          | -                                                                                    |
| `ui.load`            | An operation on a mobile UI          | -                                                                                    |

## [Android-Specific Span Operations](https://develop.sentry.dev/sdk/telemetry/traces/modules/app-starts.md#android-specific-span-operations)

| Span OP                | Description                                                                         |
| ---------------------- | ----------------------------------------------------------------------------------- |
| `activity.load`        | Calling `onCreate` for an activity                                                  |
| `application.load`     | Calling the application `onCreate`                                                  |
| `contentprovider.load` | Calling `onCreate` for a content provider                                           |
| `db.sql.room`          | A database query using the Room library                                             |
| `process.load`         | Duration of time spent by the OS prior to the first content provider initialization |