---
title: Dart configuration
description: 'Release, sampling, analytics, and feature flags for the talaria package.'
package: talaria
tags:
  - dart
  - analytics
  - feature-flags
  - sampling
  - release
id: dart-configuration
navTitle: Configuration
type: guide
section: platforms
platform:
  - dart
feature:
  - analytics
  - feature-flags
order: 50
lastReviewed: '2026-10-29'
owner: docs
---
# Dart configuration

## What you're setting up

Release, sampling, analytics, and feature flags for the talaria package.

## Steps

### 1. Release

Pass `release` as a version or git SHA through `--dart-define=TALARIA_RELEASE=…` or your own environment. Local runs should still send one. Release health groups on that string.

### 2. API key and environment

The API key chooses the environment. Do not add an environment field to `TalariaOptions`. Compile the define into the binary you ship. A development key is for local runs. Restart after rotating a rejected key. The failure is cached for about 24 hours.

### 3. Sampling

Successful traces follow the traces sample rate from Project settings. Error traces stay. A response with `retry: false` stops that signal until the process starts again.

### 4. Project settings

Tracing and analytics follow [Project configuration](../../get-started/project-settings.md). Dart always fetches project configuration.

### 5. Analytics

Enable Analytics in Project settings. This package has no consent-banner integration. `optIn` is the call that allows sending when you have already collected consent in the app. Server-side tools pass `userId` or `anonymousId` on the call.

```dart
await Talaria.analytics.identify('user_42', traits: {'plan': 'pro'});
await Talaria.analytics.track(
  'Invoice Sent',
  properties: {'plan': 'pro'},
  userId: 'user_42',
);
```

`page` and `screen` are on the same client. See [Product analytics setup](../../features/analytics.md).

### 6. Feature flags

```dart
final on = await Talaria.flags.boolVariation('new-checkout', false);
```

`stringVariation` and `jsonVariation` take a key and a default. When you need local evaluation (a server that should not round-trip on every read), call `Talaria.flags.loadDefinitions()` once at startup. That requires `flags:read` on a secret key. Mobile clients should stay on remote evaluate.

### 7. Privacy in events

`setExtra` is a map of app metadata. Do not put tokens or raw queries there. `DbSpan` stores a sanitized statement, not bind values, when you pass SQL through it.

## Check it worked

`search_issues` with `environment: development` for a local key. `get_project_stats` analytics counts stay at 0 while analytics is off.

## Next steps

- [Dart SDK](README.md)
- [Instrumentation and tracing](tracing.md)
- [Errors, logs, and breadcrumbs](errors.md)