hydra-ogmios

This program provides a similar interface to ogmios, but for hydra instead of cardano. It connects to the hydra node's websocket port and provides a websocket server allowing clients to follow transactions on the head in real time and submit new transactions.

This program works by maintaining a list of "blocks" where a block is treated as a set of transactions. When it recieves a "TransactionConfirmed" message from hydra, the transaction is recorded in memory. When it receives a "SnapshotConfirmed" message, the set of transactions in the snapshot are treated as a new block which is appended to the list. This program maintains a cursor for each ogmios client and responds to each "NextBlock" request with the block corresponding to that client's cursor.

UDP sink example implementation

The program can optionally obtain hydra events via UDP stream instead of by connecting to the hydra node's websocket API. This requires running a hydra node with a custom UDP event sink. An example implementation can be found here:

https://github.com/SundaeSwap-finance/hydra/commit/90ffe09f649c44fadd1683432d764b5eeb9086b6

Example FindIntersect request

{
  "jsonrpc": "2.0",
  "method": "findIntersection",
  "params": {
    "points": [
      "origin"
    ]
  }
}

Example FindIntersect response

{
  "jsonrpc": "2.0",
  "method": "findIntersection",
  "result": {
    "intersection": {
      "id":
 "d7455525a5d411a50ecb82883e4c2009009894b398a0f0d77800de779b640c4943d427514249dada8e21895dd0ff936c5e719a82a5c3b37d22fe6b6bf77ff8cf",
      "slot": 1727956570
    },
    "tip": {
      "id": "cf308649e0df784159616ec53d6cde3aae3efe487123c5abf92c1a5c501a8b552dd4d2c4518913002f8969887074b9f091f1fab832066a2bf637af2e1e80ac94",
      "slot": 1727956692
    }
  }
}

Example NextBlock request

{
  "jsonrpc": "2.0",
  "method": "nextBlock",
  "id": null
}

Example NextBlock response

Note: In place of the slot, we use the time at which the SnapshotConfirmed message was received.

{
  "jsonrpc": "2.0",
  "method": "nextBlock",
  "result": {
    "block": {
      "era": "conway",
      "height": 0,
      "id": "2fb0ab6aa09a3400a6613ad6b4f05fedb9d7de28f3b813cf89144ba7d1ea1c4bbd142480caf341c085ef7bd1a105b7c2ec43e9100647b15cadab903c7cd4ce0f",
      "slot": 1727746433,
      "transactions": [
        {
          "fee": {
            "ada": {
              "lovelace": 0
            }
          },
          "id": "280255d00772a007db69ca914fbd6695ef5ed160489d36debe95fd0f4f789bb4",
          "inputs": [
            {
              "index": 0,
              "transaction": {
                "id": "c9a5fb7ca6f55f07facefccb7c5d824eed00ce18719d28ec4c4a2e4041e85d97"
              }
            }
          ],
          "network": "testnet",
          "outputs": [
            {
              "address": "605e4e214a6addd337126b3a61faad5dfe1e4f14f637a8969e3a05eefd",
              "datumHash": null,
              "value": {
                "ada": {
                  "lovelace": 2450000
                }
              }
            },
            {
              "address": "6069830961c6af9095b0f2648dff31fa9545d8f0b6623db865eb78fde8",
              "datumHash": null,
              "value": {
                "ada": {
                  "lovelace": 97550000
                }
              }
            }
          ],
          "spends": "inputs",
          "validityInterval": {
            "invalidAfter": null,
            "invalidBefore": null
          }
        }
      ],
      "type": "praos"
    },
    "direction": "forward",
    "tip": {
      "height": 1,
      "id": "76b365ef938e03b56a35b2b94deea61d7aca77c4119c3cc1e93c0084db0f3a1bf8c6ddcc91daf82af8f0a69ee97e35f1f7a4d496981a208772a195d2cd2fd5f4",
      "slot": 1727842225
    }
  }
}

Example SubmitTransaction request

SubmitTransaction request is the same as ogmios:

{
  "jsonrpc": "2.0",
  "method": "submitTransaction",
  "params": {
    "transaction": {
      "cbor": "84a300d9010281825820c9a5fb7ca6f55f07facefccb7c5d824eed00ce18719d28ec4c4a2e4041e85d9700018282581d605e4e214a6addd337126b3a61faad5dfe1e4f14f637a8969e3a05eefd1a0025625082581d6069830961c6af9095b0f2648dff31fa9545d8f0b6623db865eb78fde81a05d07eb00200a100d9010281825820f953b2d6b6f319faa9f8462257eb52ad73e33199c650f0755e279e21882399c05840d9226a78f6a2762ea2d914b00da642e42b8480391a41510253f50eacb4d7c694a431aa333f369c75b08e5c9bbd6e5642e3a876999db6f585792869dd36d41207f5f6"
    }
  }
}

Example SubmitTransaction response (success)

{
  "jsonrpc": "2.0",
  "method": "submitTransaction",
  "result": {
    "transaction": {
      "id": "40fe97a9c5628fe75362044c7918905ec8a59b26ef2c94283f03e6a8d5193aef"
    }
  }
}

Example SubmitTransaction response (error)

Note: code and data fields in the error case are not implemented; the message field is just a copy of the hydra node's response.

{
  "jsonrpc": "2.0",
  "method": "submitTransaction",
  "result": {
    "error": {
      "code": null,
      "data": null,
      "message": "ApplyTxError (ConwayUtxowFailure (UtxoFailure (ValueNotConservedUTxO (MaryValue (Coin 0) (MultiAsset (fromList []))) (MaryValue (Coin 100000000) (MultiAsset (fromList []))))) :| [ConwayUtxowFailure (UtxoFailure (BadInputsUTxO (fromList [TxIn (TxId {unTxId = SafeHash \"c9a5fb7ca6f55f07facefccb7c5d824eed00ce18719d28ec4c4a2e4041e85d97\"}) (TxIx {unTxIx = 0})])))])"
    }
  }
}