.NET V1.0.X


The following documentation will help you get Flagship running in your .Net environment (server-side or client side) with preconfigured methods to implement the Decision API & Bucketing.

Feel free to contact us if you have any questions regarding this documentation.

SDK features

That SDK version helps you :


  • This SDK requires .Net with the following target framework versions:
    • net40
    • net45
    • netstandard2.0
    • net5.0
  • Your server/device must have an access to the internet.

Good to know

Getting Started


Follow these steps to install the .Net SDK

Install from nuget

To install from nuget, just run a Install-Package Nuget command to add the SDK to your project

Install-Package Flagship.SDK


Environment ID

You can find your environment id in the parameters\integration section of your Flagship account. (Check Getting Started)

// Use the Flagship package
using Flagship;
// ...
// Using the Decision API (default)
var client = FlagshipBuilder.Start(

// Using the Bucketing mode
var builder = new FlagshipOptions.Builder()

var client = FlagshipBuilder.Start(
  new FlagshipOptions.Builder()

To initialize and start the library, just call the Start function of the Flagship package,
using the bucketing function builder if you want to use the bucketing mode

The start function return a Flagship client instance for your environment.

envIdstringEnvironment id provided by Flagship.
apiKeystringApi authentication key provided by Flagship.
optionsFlagshipOptionsOption to customize the SDK behavior


You can find your apiKey and your environmentId on your Flagship account, in Parameters > Environment & Security. Find this ID

Decision Mode

API Mode

When the SDK is running in API mode, the campaign assignments and targeting validation take place server-side.
In this mode, each call to the SynchronizeModifications method from the visitor instance to refresh the modifications will create an HTTP request.


When the SDK is running in BUCKETING mode, the SDK downloads all the campaigns configurations at once in a single bucketing file so that variation assignment can be computed client-side by the SDK.
This bucketing file is stored in cache and will only be downloaded again when campaign configurations are modified in the Flagship interface.
It is possible to configure the interval of polling refresh with the PollingInterval configuration builder. Learn more


You can customize the SDK behavior using the FlagshipOptions class.
The FlagshipOptions class can be created with the FlagshipOptions.Builder class:

var builder = new FlagshipOptions.Builder()

The FlagshipOptions.Builder object has the following methods:

Builder WithDecisionMode(Mode mode)

Start Flagship SDK in the selection mode (API is the default).

ModeMode (enum)Decision mode to select for the SDK

Builder WithAPIOptions(TimeSpan timeout)

Customize the options for the API decision mode.
Right now, the only option is the timeout.
If the Decision API call times out after the specified timeout, then default modification values will be returned when calling GetModifications.

timeoutTimeSpanThe Decision API call timeout

Builder WithBucketingOptions(TimeSpan? pollingInterval = null)

WithBucketingOptions method enables you to customize the bucketing engine.
For now, the only available option is the the polling interval, to determine how often
the bucketing engine will poll the Flagship CDN for the newest configuration.

pollingIntervalTimeSpan?Bucketing polling interval (default to 1 minute).

Create a visitor

The SDK provides a method create a new visitor with an ID and a context.

The visitor context is a property dataset which defines the current user of your app. This dataset is sent and used
by the Flagship decision API as targeting for campaign allocation. For example, you could pass a VIP status in the context and then the decision API would enable or disable a specific feature flag.


Visitor context values are used to match a visitor to the targeting of a campaign


Visitor context values type must be:

  • string
  • number (int, float or double)
  • bool
// Create visitor context
var context = new Dictionary<string, object>();
context.Add("key", "value");
// Create a visitor
var visitor = client.NewVisitor("visitor_id", context);

The NewVisitor function takes the following parameters:

visitorIDstringThe ID of the visitor (must be unique for a visitor)
contextmap[string]interface{}The context of the visitor. It should match those defined in your campaigns to target your users on it.

Updating the visitor Context

The visitor context can be updated in case some context linked to your visitor has changed.
The SDK provides 2 methods to change the visitor context:

  • Either change a single key of the context
  • Or replace the whole context with a new one
// Update a single key
visitor.UpdateContext("vipUser", true);
visitor.UpdateContext("age", 30);

// Update the whole context
var newContext = new Dictionary<string, object>();
newContext.Add("vipUser", true);
newContext.Add("age", 30);

void UpdateContext(string key, object value)

This functions update the visitor context value matching the given key.
A new context value associated with this key will be created if there is no previous matching value.

keystringkey to associate with the following value
valueobjectnew context value

void UpdateContext(IDictionary<string, object> context);

newContextIDictionary<string, object>new context dictionary


Visitor context values type must be:

  • string
  • number (int, float or double)
  • bool

Campaign synchronization

Synchronizing campaigns

Synchronizing campaign modifications allows you to automatically call the Flagship decision API (or bucketing engine), which makes the allocation according to user context and gets all their modifications.

All the applicable modifications are stored in the SDK and are updated synchronously when SynchronizeModifications() is called.

This function has no parameters, and return an awaitable Task:

Task SynchronizeModifications();

Example of utilisation:

// In an async function
await visitor.SynchronizeModifications();


SynchronizeModifications must be called before trying to get a modification value

Getting modifications

Once the campaign has been assigned and synchronized all the modifications are stored in the SDK. Then, you can retrieve them with the following functions:

var discountName = visitor.GetModification("discountName", "Black Friday", true);

// If there is not error (and if there is, your value will still be set to defaut), you can use your modification value in your business logic
var discountValue = getDiscountFromDB(discountName);

GetModification is a generic method that takes a modification key, a default value & a bool and returns the modification value.

T GetModification<T>(string key, T defaultValue = default, bool activate = true)

keystringYeskey associated to the modification.
defaultValuestring, bool, int, float, double, ObjectYesdefault value returned when the key doesn't match any modification value.
activateboolNofalse by default Set this parameter to true to automatically report on our server that the current visitor has seen this modification. If false, call the ActivateModification() later.

Getting campaign information

You may need to send campaign IDs to a third-party for reporting and/or analytics purposes. It is now possible to retrieve campaign IDs for a specific modification key.

var infos = visitor.GetModificationInfo("key");

ModificationInfo GetModificationInfo(string key)

keystrKey associated with the modification.

It returns a struct containing CampaignId, VariationGroupID, VariationID, IsReference, or null if the modification is not found (i.e. user does not belong to the campaign).

Activating modifications

Once a modification has been printed on the screen for a user, you must send an activation event to tell Flagship that the user has seen this specific modification.

// Activate the modification automatically when retrieving it
var color = visitor.GetModification("discountName", "Black Friday", true);

// ---OR---

// Activate the modification later on manually

Task ActivateModification(string key);

keystringkey which identifies the modification

Hit Tracking

This section helps send tracking and learn how to build hits in order to aprove campaign goals.

The different types of Hits are:

They must all be built and sent with the following function:

Task SendHit<T>(T hit) where T : BaseHit;

Common parameters

These parameters can be sent with any type of hit. They are part of the BaseHit class that all Hit types implements

UserIPstringoptional User IP
ScreenResolutionstringoptional Screen Resolution.
UserLanguagestringoptional User Language
CurrentSessionTimeStampstringoptional Current Session Timestamp
SessionNumberintoptional Session Number

Hit types


await visitor.SendHit(new Page
  DocumentLocation: "http://localhost:8080",

This hit should be sent each time a visitor arrives on a new interface.

Hit parameterTypeRequiredDescription
DocumentLocationstringYesURL of the page, must be a valid URL


await visitor.SendHit(new Screen
  DocumentLocation: "My interface name",

This hit should be sent each time a visitor arrives on a new interface.

Hit parameterTypeRequiredDescription
DocumentLocationstringYesName of the interface


This hit should be sent when a user complete a Transaction.

await visitor.SendHit(new Transaction
    Id = "tid",
    Affiliation = "affiliation"
Hit ParameterTypeRequiredDescription
TransactionIdstringYesTransaction unique identifier.
AffiliationstringYesTransaction name. Name of the goal in the reporting.
Revenuedecimal?NoTotal revenue associated with the transaction. This value should include any shipping or tax costs.
Shippingdecimal?NoSpecifies the total shipping cost of the transaction.
ShippingMethodstringNoSpecifies the shipping method of the transaction.
Taxdecimal?NoSpecifies the total taxes of the transaction.
CurrencystringNoSpecifies the currency used for all transaction currency values. Value should be a valid ISO 4217 currency code.
PaymentMethodstringNoSpecifies the payment method for the transaction.
ItemCountint?NoSpecifies the number of items for the transaction.
CouponCodestringNoSpecifies the coupon code used by the customer for the transaction.


This hit is linked to a transaction. It must be send after the corresponding transaction.

await visitor.SendHit(new Item
    TransactionId = "tid",
    Name = "product",
    Code = "product-1"

class Item(transactionId: string, productName: string) : HitBuilder<Item>()

Hit ParameterTypeRequired Description
TransactionIdstringYesTransaction unique identifier.
NamestringYesProduct name.
PricedoubleNoSpecifies the item price.
CodestringYesSpecifies the item code or SKU.
CategorystringNoSpecifies the item category.
QuantityintNoSpecifies the item quantity


This hit can be anything you want: for example a click or a newsletter subscription.

await visitor.SendHit(new Event
    Category = EventCategory.ActionTracking,
    Action = "bookedEvent",
    Value = 1
Hit ParameterTypeRequired Description
CategoryEventCategoryYescategory of the event ("Action Tracking" or "User Engagement").
ActionstringYesthe event action.
LabelstringNolabel of the event.
ValueintNoSpecifies a value for this event. must be non-negative.

Release notes



  • Basic flow
  • Decision modes API & Bucketing
  • OptionBuilder