# High-Level Architecture

dSunbird-RC's credentialling service is an amalgamation of three microservices.

* **Identity Microservice:** This service is the central lynchpin to maintain identities across the system. All identities in Sunbird-RC are DID-compliant and are web-resolvable. The other microservices (Credential Schema Service and Credential Service) depend on this for generating any identity.
* **Credential Schema Microservice:** This service stores the schema of the Verifiable Credential along with the associated view template.
* **Credential Issuance Microservice:** This is the core issuance service. This service is called with the payload, which is then transformed into a W3C-compliant Verifiable Credential in JSON-LD format.  The payload is then signed using the private key which was generated as part of the original Issuer creation. 

### High level component Diagram

<figure><img src="https://1967278543-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjLrXPhvTmZD220FLQYLt%2Fuploads%2FpnTqnu0YS6o36j5QYVrJ%2Fcredentialling.drawio.png?alt=media&#x26;token=ef3b2b1b-2903-4592-9583-728cbea6d67b" alt=""><figcaption></figcaption></figure>

### How it works

The sequence diagram explains the following flows:

* Creating an identity
* Creating a schema
* Issuing a Credential
* Verifying a Credential

<figure><img src="https://1967278543-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjLrXPhvTmZD220FLQYLt%2Fuploads%2FHr3EjxAPj4xC6QnRs2jQ%2Fcredential-sequence-1.png?alt=media&#x26;token=dbf8c272-e19e-43f3-83d6-ba0fa87f0b6d" alt=""><figcaption></figcaption></figure>