Setup guide

NOTE: Current implementation of refresh service works only with issuer-node.

Preparation

Run the issuer-node locally by following the quick-start installation guide.
Clone the refresh service using the command git clone [email protected]:0xPolygonID/refresh-service.git.
Build JSON and JSONLD schemas, utilizing the provided examples:

Generate custom schemas through the schema builder. Additional details can be found in the schema builder documentation.

Setup with custom data provider

Consider an example of integrating polygon scan as a data provider for the refresh service.

Integrate the custom data provider into the data provider module:

const polygonBalanceURL = "https://api.polygonscan.com/api?module=account&action=balance&address=%s&apikey=%s"

type BalanceResponse struct {
  Status  string `json:"status"`
  Result  string `json:"result"`
  Message string `json:"message"`
}

func GetBalanceByAddress(address string) (map[string]any, error) {
  resp, err := http.Get(
    fmt.Sprintf(polygonBalanceURL, address, "<POLYGON_SCAN_TOKEN>"),
  )
  if err != nil {
    return nil,
      fmt.Errorf("failed to get balance: %w", err)
  }

  balanceResp := &BalanceResponse{}
  if err = json.NewDecoder(resp.Body).Decode(balanceResp); err != nil {
    return nil,
      fmt.Errorf("failed to decode balance response: %w", err)
  }
  defer resp.Body.Close()

  if balanceResp.Status != "1" {
    return nil,
      fmt.Errorf("invalid status in balance response: %s", balanceResp.Message)
  }

  // convert to credential subject format
  // ensure that these fields align with the attributes specified in the JSONLD schema.
  return map[string]any{
    "balance": balanceResp.Result,
    "address": address,
  }, nil
}

Use the custom data provider within the refresh service:

Remove the default data provider:

flexibleHTTP, err := rs.providers.ProduceFlexibleHTTP(credentialType)
if err != nil {
  return nil,
    errors.Wrapf(ErrCredentialNotUpdatable,
      "for credential '%s' not possible to find a data provider: %v", credential.ID, err)

}
updatedFields, err := flexibleHTTP.Provide(credential.CredentialSubject)
if err != nil {
  return nil, err
}

Use the new polygon scan data provider:

// confirm the credentialType matches a supported type in the refresh service,
// and its urn:uuid aligns with the id in the JSONLD schema
if credentialType != "urn:uuid:f50cfcf6-ded4-470e-83be-2d6820a66998" {
  return nil, errors.New("unknow credentialType")
}

updatedFields, err := polygonscan.GetBalanceByAddress(credential.CredentialSubject["address"].(string))
if err != nil {
  return nil, err
}

Populate the .env variables:

export IPFS_GATEWAY_URL="https://infura..."
export SUPPORTED_RPC="137=https://infura..."
export SUPPORTED_STATE_CONTRACTS="137=0x624ce98D2d27b20b8f8d521723Df8fC4db71D79D"
export SUPPORTED_ISSUERS="*=https://my-issuer-node.com"
export ISSUERS_BASIC_AUTH="*=myuser:mypassword"

Generate a blank config.yaml file:

touch config.yaml

Run the refresh service:

source .env
go run .

Setup with default provider

To integrate polygon scan data provider with the default data provider, follow these general steps:

Create a config.yaml file with the following content:

urn:uuid:f50cfcf6-ded4-470e-83be-2d6820a66998:
  settings:
    timeExpiration: 5m
  provider:
    url: https://api.polygonscan.com/api
    method: GET
  requestSchema:
    params:
      module: account
      action: balance
      address: "{{ credentialSubject.address }}" # this value will be substituted from the credentialSubject.address field
      apikey: <POLYGON_SCAN_TOKEN>
    headers:
      Content-Type: application/json
  responseSchema:
    type: json
    properties:
      result:
        type: string
        match: credentialSubject.balance

Populate the .env variables:

export IPFS_GATEWAY_URL="https://infura..."
export SUPPORTED_RPC="137=https://infura..."
export SUPPORTED_STATE_CONTRACTS="137=0x624ce98D2d27b20b8f8d521723Df8fC4db71D79D"
export SUPPORTED_ISSUERS="*=https://my-issuer-node.com"
export ISSUERS_BASIC_AUTH="*=myuser:mypassword"

Run the service:

source .env
go run .

Testing

Go to the issuer-node UI and generate a credential with refresh service section:
Credential request
Retrieve the credential through the PolygonID mobile application. If the expiration date in the credential request was set in the past, the credential is supposed to be expired:
Expired credential
Visit https://verifier-demo.polygonid.me/ to create a proof request. This is necessary because https://schema-builder.polygonid.me/query-builder does not currently support the xsd:positiveInteger type:
Proof request
Scan the QR using the PolygonID mobile application. During the refreshing process, you are expected to encounter the following message:
Refresh process
As a result, the successful completion of the verification process is expected, wallet must have one expired credential and one refreshed credential:
Result

Preparation​

Setup with custom data provider​

Setup with default provider​

Testing​

Preparation

Setup with custom data provider

Setup with default provider

Testing