> For the complete documentation index, see [llms.txt](https://docs.energyweb.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.energyweb.org/legacy-documentation/ew-dos-technology-components-2023/identity-and-access-management-iam/ssi-hub.md).

# SSI Hub

## SSI Hub

NodeJS server application using [NestJS](https://nestjs.com/) framework. The server caches specific smart contract data such as [ENS namespaces](https://ens.domains/) and [DID documents](/legacy-documentation/foundational-concepts/self-sovereign-identity-introduction.md#did-documents) in order to improve read-query performance for applications and packages that rely on on-chain data.

The SSI Hub also facilitates the credentials exchange between credential requesters and issuers, which enables other applications such as [Switchboard](broken://pages/-Mdw3Vke0uRCbFguK6gD#switchboard) or [Decentralized Service Bus](#decentralized-service-bus) to use credentials for role permissioning.

SSI Hub **persists** the following information that is created, read and updated by the [IAM library](#identity-access-and-management-iam-client-library):

* Organization namespaces
* Application namespaces
* Role namespaces
* User [credentials](https://github.com/energywebfoundation/ewf-gitbook/blob/develop/foundational-concepts/credentials.md)

### **Documentation Resources**

* [GitHub repository](https://github.com/energywebfoundation/iam-cache-server)
* [ReadTheDocs](https://energy-web-foundation-did-acl-cache-server.readthedocs-hosted.com/en/latest/api/globals/)

#### See an overview of all Identity and Access Management (IAM) components in EW-DOS [here](/legacy-documentation/foundational-concepts/self-sovereign-identity-introduction.md#ew-dos-identity-and-access-management-stack)

### Dependencies and Dependents

| EW-DOS Dependencies                                                                                         | EW-DOS Dependents                                              |
| ----------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------- |
| [DID Library](#did-library)                                                                                 | [Decentralized Service Bus](#decentralized-service-bus)        |
| [Energy Web Chain](/legacy-documentation/ew-dos-technology-components-2023/trust-layer-energy-web-chain.md) | [Switchboard](broken://pages/-Mdw3Vke0uRCbFguK6gD#switchboard) |
| [IAM Smart Contracts](https://github.com/energywebfoundation/iam-contracts)                                 | EV-Dashboard                                                   |


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