Integrate enmeshed

Communication and sharing of information between two Identities requires the existence of a Relationship between them. This guide describes how a Connector can establish an active Relationship to another Identity. Firstly, we explain how to create a RelationshipTemplate on a Connector, the so-called templator, and how to make the RelationshipTemplate available to the other Identity. The RelationshipTemplate can then be used by the other Identity, the so-called initiator, to initiate a Relationship with the templator. This Relationship can finally be accepted by the templator in order to establish an active Relationship between them.

Create a RelationshipTemplate

The creation of a RelationshipTemplate on the templator is the first required step in the process of establishing a Relationship. A RelationshipTemplate is a formal description of the aspects of a Relationship that can be established between two Identities. In particular, it can specify a Request sent from the templator to the initiator, which must be accepted by the initiator as a prerequisite for the establishment of the Relationship.

Input for Creating a RelationshipTemplate

To create a RelationshipTemplate on the templator, you need to follow the instructions described in the Create own RelationshipTemplate use case documentation using the following JSON payload as input:

{
  "maxNumberOfAllocations": <maximum number of allocations>,
  "expiresAt": "<expiration date of RelationshipTemplate>",
  "content": {
    // RelationshipTemplateContent or ArbitraryRelationshipTemplateContent
    ...
  }
}

You need to replace the placeholders marked with <...> appropriately as usual. The maxNumberOfAllocations property is optional, so you can omit it. If you need help filling the content property or the maxNumberOfAllocations property with appropriate values, see the RelationshipTemplate description in the Data Model Overview. It is important to note that if you intend to use the RelationshipTemplate to establish a Relationship between the templator and an App user, you must use a RelationshipTemplateContent as the value of the content property. The input must then be as follows:

{
  "maxNumberOfAllocations": <maximum number of allocations>,
  "expiresAt": "<expiration date of RelationshipTemplate>",
  "content": {
    // RelationshipTemplateContent
    "@type": "RelationshipTemplateContent",
    "title": "<title of RelationshipTemplate>",
    "metadata": <custom metadata>,
    "onNewRelationship": {
      // Specification of a Request
      ...
    },
    "onExistingRelationship": {
      // Specification of another Request
      ...
    }
  }
}

The properties content.title, content.metadata and content.onExistingRelationship are optional, so you can omit them. In case the content property of the RelationshipTemplate contains a RelationshipTemplateContent and therefore in particular at least one Request, you should check the Requests’ validity before you create the RelationshipTemplate. An Identity to which the RelationshipTemplate will be made available and which does not yet have a Relationship to the templator will receive the Request specified in the onNewRelationship property of the RelationshipTemplateContent. However, if a Relationship already exists between them and a Request has been specified in the onExistingRelationship property of the RelationshipTemplateContent, the Identity will receive this Request instead.

How to send a Request via a RelationshipTemplate is explained in detail in the Requests via RelationshipTemplates guide.

If the RelationshipTemplate is intended to establish a Relationship between the templator and another Connector, an ArbitraryRelationshipTemplateContent can be used instead of a RelationshipTemplateContent as the value of the RelationshipTemplate’s content. An ArbitraryRelationshipTemplateContent has a single value property with no type restriction and is appropriate if the standard way is insufficient.

Personalize the RelationshipTemplate

If the RelationshipTemplate is only for creating a Relationship with a single known Identity, you can set that Identity’s address in the RelationshipTemplate:

{
  // ...
  "content": {
    // ...
  },
  "forIdentity": "<address that the RelationshipTemplate is intended for>"
}

Only that Identity will be able to continue with establishing a Relationship. This also protects sensitive data of that Identity contained in the RelationshipTemplate from outside access.

Successfully Created RelationshipTemplate

If you have successfully created the RelationshipTemplate on the templator, you will receive a success response from which you can read its id. As the templator is the creator of the RelationshipTemplate, the createdBy property contains the Address of the templator. For this reason, the value of the isOwn property is set to true in this context.

Save the id of the RelationshipTemplate so that you can refer to it and make it available to other Identities later. For the same reason, save the value of the property truncatedReference.

Make the RelationshipTemplate Available

For an Identity to initiate a Relationship with the templator, it must use a valid RelationshipTemplate which is owned by the templator. Depending on whether the Identity is a Connector or an App user, a different approach must be used to make the RelationshipTemplate available to the Identity:

Make It Available to a Connector

If a Connector wants to initate a Relationship with the templator, it must first load a RelationshipTemplate, which is owned by the templator, onto itself. This can be done by following the Load RelationshipTemplate created by others use case description and providing the input:

{
  "reference": "<truncated reference of RelationshipTemplate>"
}

In doing so, it is necessary to insert the value of the truncatedReference property read from the created RelationshipTemplate into the reference property.

When the RelationshipTemplate of the templator is successfully loaded onto the Connector, the transport.peerRelationshipTemplateLoaded Connector event is triggered and a success response is sent. This success response looks like the success response you receive when you have successfully created a RelationshipTemplate on the templator, except that the value of the property isOwn is now false instead of true. Assuming that there is no Relationship between the Connector and the templator yet and that the RelationshipTemplate contains a RelationshipTemplateContent in its content property, the Connector will additionally receive a new incoming Request. The Integrator of the Connector can accept it if they want to initiate a Relationship with the templator.

Make It Available to an App User

If an App user wants to initiate a Relationship with the templator, the App user must first scan a QR code that contains the reference to a RelationshipTemplate which is owned by the templator. To create this QR code on the templator, proceed as described in the documentation of the Get RelationshipTemplate use case, use the id of the created RelationshipTemplate and specify the value image/png in the Accept header field. After scanning the QR code, the App user receives the conditions for establishing a Relationship to the templator as specified in the RelationshipTemplate. If these are accepted, the App user can now initiate a Relationship with the templator.

Initiate a Relationship

After the templator has created a RelationshipTemplate and made it available to another Identity, this Identity can use it to initiate a Relationship with the templator. For this reason, this other Identity is also referred to below as the initiator.

Check the Feasibility of a Relationship Initiation

There may be several reasons why a RelationshipTemplate has been received but it is not possible to establish a Relationship based on it. The RelationshipTemplate could have already expired, for example, or the templator has deleted its Identity in the meantime. The Check if Relationship can be created use case can be executed to check whether a Relationship currently can be initiated based on a given RelationshipTemplate. Consult the use case documentation for more details on the various reasons why it may not be possible to initiate a Relationship.

Initiate It as a Connector

Assuming that the initiator in this section is a Connector, our starting situation is that the initiator has successfully loaded the created RelationshipTemplate onto itself. The received RelationshipTemplate may or may not contain a RelationshipTemplateContent in its content property. We now describe separately in both cases how the initiator can use the RelationshipTemplate to initiate a Relationship with the templator. An overview of this procedure is given in the following diagram.

RelationshipTemplate With RelationshipTemplateContent

We assume that there is no Relationship between the initiator and the templator yet and that a RelationshipTemplateContent is used within the RelationshipTemplate. In this case, the initiator receives a new incoming Request after loading the RelationshipTemplate and the consumption.incomingRequestReceived Connector event is triggered. By proceeding as described in the Query incoming Requests use case documentation and specifying source.reference=<ID of RelationshipTemplate> as a query parameter, this Request can be queried on the initiator. The result contains the corresponding LocalRequest, from which you can read the id of the Request.

Save the id of the incoming Request so that you can accept or reject it.

The content of the LocalRequest is the Request specified in the onNewRelationship property of the RelationshipTemplateContent. This Request defines the conditions for establishing an active Relationship between the initiator and the templator. If the initiator agrees to them, it can initiate a Relationship with the templator by accepting the Request.

The Request Module enabled by default ensures that the initiator receives a new incoming Request when the RelationshipTemplate is loaded and that a Relationship is initiated by accepting the incoming Request. If an Integrator of a Connector has disabled the Request Module, they must trigger these and other processes manually, which is not described in this guide. Please note, however, that App users cannot deactivate the Request Module, which is why their processes are more standardized.

Accepting the Request is done by following the instructions of the Accept incoming Request use case and providing the id of the Request as well as an appropriate input to build the Response of the initiator to the Request. In case of success, the status of the LocalRequest will change from "ManualDecisionRequired" to "Decided" and the consumption.incomingRequestStatusChanged Connector event will be triggered. The Response of the initiator to the Request will be contained within the response.content property of the LocalRequest. By accepting the Request, a data object of type Relationship with "Pending" as status is created and the transport.relationshipChanged Connector event is triggered. The Relationship’s creationContent.response property contains the initiator’s Response to the Request.

It is not necessary, but you can query this Relationship by proceeding as described in the Query Relationships use case documentation, using the query parameter template.id=<ID of RelationshipTemplate>. If you decide to do this, you will receive a result as response from which you can read the id of the Relationship.

Note that it is of course also possible to reject the incoming Request, if the initiator does not wish to establish an active Relationship to the templator under the given conditions. In order to do this, make use of the documentation of the Reject incoming Request use case. More detailed information about how to reject as well as how to accept an incoming Request can also be found in the Requests via RelationshipTemplates guide.

RelationshipTemplate With ArbitraryRelationshipTemplateContent

We now consider the situation in which the RelationshipTemplate loaded onto the initiator contains an ArbitraryRelationshipTemplateContent in its content property instead of a RelationshipTemplateContent. In this case, the initiator does not receive an incoming Request. Nevertheless, it can initiate a Relationship with the templator by explicitly creating a data object of type Relationship with "Pending" as status based on the RelationshipTemplate. To do this, follow the instructions of the Create Relationship with RelationshipTemplate use case, use an ArbitraryRelationshipCreationContent as creationContent and provide as input:

{
  "templateId": "<ID of RelationshipTemplate>",
  "creationContent": {
    // ArbitraryRelationshipCreationContent
    ...
  }
}

In case of success, the transport.relationshipChanged Connector event will be triggered and you will receive a result as response, which contains the created data object of type Relationship. The specified ArbitraryRelationshipCreationContent is contained within the creationContent property of the Relationship.

Saving the id of the Relationship is useful if you want to return to the created Relationship later in order to retrace changes to the Relationship.

Initiate It as an App user

As already mentioned in the description of the input for creating a RelationshipTemplate, a RelationshipTemplateContent must be used as the value of the content property of the RelationshipTemplate if you intend to use the RelationshipTemplate to establish a Relationship between the templator and an App user. Assuming that there is no Relationship between them yet, the App user receives the Request specified in the onNewRelationship property of the RelationshipTemplateContent after scanning the QR code associated with the RelationshipTemplate. The App user has the option of accepting or rejecting the Request. If they accept the Request appropriately, a Relationship with the templator is initiated. This means the creation of a data object of type Relationship with "Pending" as status. The Response of the App user to the Request is contained within the creationContent.response property of the Relationship.

Please note that the general procedure is the same if an App user instead of a Connector wants to initiate a Relationship with the templator. The difference is that the RelationshipTemplate does not need to contain a RelationshipTemplateContent in its content property if it is intended to be used by a Connector.

Undo the Initiation of a Relationship

The initiation of a Relationship by the initiator leads to the creation of a Relationship with "Pending" as status. After that, the templator has the option of establishing an active Relationship by accepting the pending Relationship. Before the templator has accepted the pending Relationship, the Integrator of the initiator may change their mind and no longer want to establish an active Relationship. In this case, the initiator can revoke the pending Relationship by executing the Revoke Relationship use case. As a result, the status of the Relationship changes from "Pending" to "Revoked". This revoked Relationship can then no longer be accepted by the templator in order to establish an active Relationship.

If the initiator initiates another Relationship at a later point in time, a new Relationship is created with "Pending" as status. The status of the previous Relationship is not changed from "Revoked" to "Pending". This means that previous attempts to establish an active Relationship, which were then revoked by the initiator, can still be viewed by executing the Query Relationships use case using the status=Revoked query parameter.

Establish an Active Relationship

After the initiator has initiated the Relationship, the Integrator of the templator can accept it if they want to establish an active Relationship to the initiator. We now explain all required steps for establishing an active Relationship, including the necessary synchronization of the templator and any other Connector that may be involved at certain points in time. Please note that the synchronization can also be automated by using the Sync Module.

Receive the Pending Relationship

The templator must first synchronize the updates of the Backbone in order to receive the data object of type Relationship with "Pending" as status previously created by the initiator. The synchronization causes the transport.relationshipChanged Connector event to be triggered and the result of the response after synchronization contains the information about the created Relationship. In particular, the id of the Relationship can be read from it.

Read the id of the Relationship from the relationships.id property for the next step.

Accept the Pending Relationship

If the templator accepts the pending Relationship, the status of the data object of type Relationship will change from "Pending" to "Active" and therefore an active Relationship between the templator and the initiator will be established. In addition, the transport.relationshipChanged Connector event will be triggered. To accept the pending Relationship, consult the Accept Relationship use case description and specify the id of the Relationship.

For rejecting the pending Relationship and therefore not establishing an active Relationship between the templator and the initiator, take a look at the documentation of the Reject Relationship use case. By rejecting a pending Relationship, its status changes from "Pending" to "Rejected". This rejected Relationship can then no longer be accepted by the templator in order to establish an active Relationship. If the templator has rejected a pending Relationship and the initiator initiates another Relationship at a later point in time, a new Relationship is created with "Pending" as status. The status of the previous Relationship is not changed from "Rejected" to "Pending". This means that previous attempts to establish an active Relationship, which were then rejected by the templator, can still be viewed by executing the Query Relationships use case using the status=Rejected query parameter.

Get Informed About the Acceptance of the Relationship

Assuming the initiator is a Connector, it must synchronize the updates of the Backbone after the templator has accepted the Relationship. The synchronization causes the transport.relationshipChanged Connector event to be triggered and the result of the response after synchronization shows in particular that the status of the Relationship has been changed from "Pending" to "Active". Now the initiator is informed that the templator has accepted the Relationship and therefore an active Relationship has been established between them. If the initiator is an App user instead, they are informed about the acceptance of the Relationship analogously.

What’s Next?

After an active Relationship between the two Identities is established, they are able to share information with each other. For example, they can exchange Messages. A possible scenario that demonstrates how a Connector can send a Message to another Identity with which it has an active Relationship is described in the Requests via Messages scenario documentation. It is also possible for both Identities involved in the Relationship to terminate the Relationship as soon as it is no longer wanted.