{
  "openapi": "3.0.1",
  "info": {
    "title": "SSIMPL",
    "description": "A reference API specification for the Relay Peers of the SSIMPL protocol",
    "contact": {
      "name": "SSIMPL",
      "url": "https://ssimpl.org",
      "email": "harvey.rabbit@protonmail.com"
    },
    "version": "0.1.0"
  },
  "security": [
    {
      "Authorization": [
        "Bearer <Signed DID in SignatureEnvelope format, multibase-encoded>"
      ]
    }
  ],
  "paths": {
    "/peer": {
      "post": {
        "tags": [
          "Relay Peer"
        ],
        "summary": "Announce that the calling Relay Peer is active",
        "description": "Returns a signed DID matching",
        "operationId": "announceRelayPeer",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/SignedRelayPeerAnnouncement"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "OK"
          }
        }
      }
    },
    "/peer/identity": {
      "post": {
        "tags": [
          "Relay Peer"
        ],
        "summary": "Verify whether this Relay Peer exists and is healthy",
        "description": "Returns a signed DID matching",
        "operationId": "pingRelayPeer",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/SignedDID"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Relay Peer ping response",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/SignedDID"
                }
              }
            }
          }
        }
      }
    },
    "/ledger/delta": {
      "post": {
        "tags": [
          "Ledger"
        ],
        "summary": "Request ledger delta",
        "description": "Returns ledger entries newer than the provided epoch if the caller is out of sync.",
        "operationId": "requestLedgerDelta",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/LedgerDeltaRequest"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Ledger delta response",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/LedgerDeltaResponse"
                }
              }
            }
          }
        }
      }
    },
    "/ledger": {
      "get": {
        "tags": [
          "Ledger"
        ],
        "summary": "Get the current state of the Ledger",
        "operationId": "getLedgerMetadata",
        "responses": {
          "200": {
            "$ref": "#/components/schemas/LedgerMetadata"
          }
        }
      },
      "post": {
        "tags": [
          "Ledger"
        ],
        "summary": "Register a DID",
        "operationId": "registerDID",
        "requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/LedgerEntry"
              }
            }
          },
          "required": true
        },
        "responses": {
          "200": {
            "description": "OK"
          }
        }
      },
      "put": {
        "tags": [
          "Ledger"
        ],
        "summary": "Revoke a DID.",
        "operationId": "revokeDID",
        "requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/SignedDID"
              }
            }
          },
          "required": true
        },
        "responses": {
          "200": {
            "description": "OK"
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "SignatureEnvelope": {
        "type": "object",
        "required": [
          "message",
          "signature",
          "signer"
        ],
        "properties": {
          "message": {
            "type": "string",
            "description": "Canonical serialized representation of the signed data"
          },
          "signature": {
            "$ref": "#/components/schemas/Signature"
          },
          "signer": {
            "type": "string",
            "description": "DID or public key identifier of the signer"
          }
        }
      },
      "Signature": {
        "type": "object",
        "required": [
          "publicKey",
          "algorithm",
          "value"
        ],
        "properties": {
          "publicKey": {
            "type": "string"
          },
          "algorithm": {
            "type": "string"
          },
          "value": {
            "type": "string"
          }
        }
      },
      "LedgerEntry": {
        "type": "object",
        "required": [
          "data",
          "signatureEnvelope"
        ],
        "properties": {
          "data": {
            "type": "object",
            "required": [
              "verifiableCredentialRoot",
              "proof"
            ],
            "properties": {
              "verifiableCredentialRoot": {
                "$ref": "#/components/schemas/VerifiableCredentialRoot"
              },
              "proof": {
                "$ref": "#/components/schemas/Proof"
              }
            }
          },
          "signatureEnvelope": {
            "$ref": "#/components/schemas/SignatureEnvelope"
          }
        }
      },
      "VerifiableCredentialRoot": {
        "type": "object",
        "required": [
          "data",
          "signatureEnvelope"
        ],
        "properties": {
          "data": {
            "type": "object",
            "required": [
              "did",
              "identityDocumentHash"
            ],
            "properties": {
              "did": {
                "type": "string"
              },
              "identityDocumentHash": {
                "type": "string"
              }
            }
          },
          "signatureEnvelope": {
            "$ref": "#/components/schemas/SignatureEnvelope"
          }
        }
      },
      "Proof": {
        "type": "object",
        "required": [
          "DG15",
          "AASignature",
          "AAChallenge",
          "SOD"
        ],
        "properties": {
          "DG15": {
            "type": "string"
          },
          "AASignature": {
            "type": "string"
          },
          "AAChallenge": {
            "type": "string"
          },
          "SOD": {
            "type": "string"
          }
        }
      },
      "SignedDID": {
        "properties": {
          "data": {
            "type": "object",
            "properties": {
              "did": {
                "type": "string"
              }
            }
          },
          "signatureEnvelope": {
            "$ref": "#/components/schemas/SignatureEnvelope"
          }
        }
      },
      "SignedRelayPeerAnnouncement": {
        "properties": {
          "data": {
            "type": "object",
            "properties": {
              "did": {
                "type": "string"
              },
              "hostname": {
                "type": "string"
              }
            }
          },
          "signatureEnvelope": {
            "$ref": "#/components/schemas/SignatureEnvelope"
          }
        }
      },
      "LedgerMetadata": {
        "properties": {
          "data": {
            "type": "object",
            "properties": {
              "epoch": {
                "type": "number"
              },
              "root_hash": {
                "type": "string"
              },
              "relay_did": {
                "type": "string"
              }
            }
          },
          "signatureEnvelope": {
            "$ref": "#/components/schemas/SignatureEnvelope"
          }
        }
      },
      "LedgerDeltaRequest": {
        "type": "object",
        "required": [
          "lastEpoch",
          "rootHash"
        ],
        "properties": {
          "lastEpoch": {
            "type": "integer",
            "format": "int64",
            "description": "Last ledger epoch known to the peer"
          },
          "rootHash": {
            "type": "string",
            "description": "Merkle root hash of the peer's current ledger state"
          }
        }
      },
      "LedgerDeltaResponse": {
        "type": "object",
        "required": [
          "currentEpoch",
          "authoritativeRootHash",
          "entries"
        ],
        "properties": {
          "currentEpoch": {
            "type": "integer",
            "format": "int64",
            "description": "Current epoch of the relay peer ledger"
          },
          "authoritativeRootHash": {
            "type": "string",
            "description": "Merkle root hash after applying returned entries"
          },
          "entries": {
            "type": "array",
            "items": {
              "$ref": "#/components/schemas/LedgerEntry"
            },
            "description": "Ordered ledger entries newer than lastEpoch"
          }
        }
      }
    }
  }
}