#### [Abblix\.SecurityEvents](https://www.abblix.com/en/docs/api/abblix-securityevents 'index')
### [Abblix\.SecurityEvents\.Delivery](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery 'Abblix\.SecurityEvents\.Delivery')

## ReplayIdentifier Class

Composes what a receiver reserves in [IReplayCache](https://www.abblix.com/en/docs/api/abblix-jwt/Abblix.Jwt.ReplayPrevention.IReplayCache 'Abblix\.Jwt\.ReplayPrevention\.IReplayCache') for one token\.

```csharp
public static class ReplayIdentifier
```

Inheritance [System\.Object](https://learn.microsoft.com/en-us/dotnet/api/system.object 'System\.Object') → ReplayIdentifier

### Remarks
Every receiver in this package answers the same question of the cache and must answer it the
same way, which is why the composition lives here rather than at each call site\. Two receivers
deriving one rule separately do not fail on the day they disagree \- they keep working, in
different key spaces, and the disagreement surfaces only when somebody tightens one of them\.
### Methods

## ReplayIdentifier\.ForToken\(string, string\) Method {#Abblix.SecurityEvents.Delivery.ReplayIdentifier.ForToken(string,string)}

Composes the identifier for a token, scoping its own identifier to its issuer\.

```csharp
public static string ForToken(string issuer, string tokenId);
```
#### Parameters

###### `issuer` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.SecurityEvents.Delivery.ReplayIdentifier.ForToken(string,string).issuer}

The `iss` claim of the token\.

###### `tokenId` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.SecurityEvents.Delivery.ReplayIdentifier.ForToken(string,string).tokenId}

The `jti` claim of the token\.

#### Returns
[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')  
The value to reserve\.

### Remarks
The issuer belongs in the value because a `jti` is unique only "within a particular
event feed" \(RFC 8417 Section 2\.2\), so reserving the identifier alone would let one
provider's token refuse another provider's\. Escaping removes the separator from both halves,
so two distinct pairs cannot compose onto one identifier \- without it an issuer ending in
the separator and a short identifier produce the same value as a shorter issuer and a longer
identifier, and one provider could reserve another's\.