onchain.signingAlgo missing when metadata.deprecated=true – violates schema contract

[olegssedacs]

In the OpenAPI spec, the field onchain.signingAlgo is marked as required and non-nullable:

    BlockchainOnchain:
      type: object
      properties:
        protocol:
          type: string
          description: The protocol of the blockchain
          example: EVM
        chainId:
          type: string
          description: Network/chain ID
          example: 1
        test:
          type: boolean
          description: Is test blockchain
          example: false
        signingAlgo:
          enum:
          - ECDSA_SECP256K1
          - EDDSA_ED25519
          type: string
          description: Signing alghorithm
          example: ECDSA_SECP256K1
      required:
      - protocol
      - test
      - signingAlgo

However, in responses where metadata.deprecated=true, the onchain.signingAlgo field is absent.

This violates the defined contract and causes client code generated from the spec to fail deserialization with an exception.

Example problematic response:

{
  "data": [
    {
      "id": "a8debd1c-745b-4cd0-9097-bf24aed7fb5c",
      "legacyId": "DIEM_XUS_TEST",
      "displayName": "Diem XUS Test",
      "nativeAssetId": "c9eadb85-aebb-49a7-856f-1517c0e16964",
      "onchain": {
        "protocol": null,
        "test": true
      },
      "metadata": {
        "scope": "GLOBAL",
        "deprecated": true
      }
    }
  ]
}

Expected behavior:

If onchain.signingAlgo is not present when deprecated=true, it should either:

• Be marked as optional in the OpenAPI schema, or
• Always included in the response (even for deprecated records), possibly as null or with a placeholder value.

Impact:
Code generation tools (e.g., OpenAPI codegen) produce clients that expect signingAlgo to be present. This discrepancy breaks deserialization and disrupts client-side processing.
Please clarify if this is an intentional behavior and if the schema should be updated to reflect this exception.