feat: get raw transaction data from bitcoin core

app/bitcoind/models.py

@@ -1,6 +1,6 @@
 from argparse import ArgumentError
 from enum import Enum
-from typing import List, Optional
+from typing import List, Optional, Union
 
 from fastapi import Query
 from pydantic.main import BaseModel
@@ -64,6 +64,55 @@ class BtcLocalAddress(BaseModel):
         )
 
 
+class RawTransaction(BaseModel):
+    in_active_chain: Union[None, bool] = Query(
+        None,
+        description='Whether specified block is in the active chain or not (only present with explicit "blockhash" argument)',
+    )
+    txid: str = Query(..., description="The transaction id (same as provided)")
+    hash: str = Query(
+        ...,
+        description="The transaction hash (differs from txid for witness transactions)",
+    )
+    size: int = Query(..., description="The serialized transaction size")
+    vsize: int = Query(
+        ...,
+        description="The virtual transaction size (differs from size for witness transactions)",
+    )
+    weight: int = Query(
+        ..., description="The transaction's weight (between vsize*4 - 3 and vsize*4)"
+    )
+    version: int = Query(..., description="The version")
+    locktime: int = Query(..., description="The lock time")
+    vin: List[dict] = Query(..., description="The transaction's inputs")
+    vout: List[dict] = Query(..., description="The transaction's outputs")
+    blockhash: str = Query(..., description="The block hash")
+    confirmations: int = Query(..., description="The number of confirmations")
+    blocktime: int = Query(
+        ..., description="The block time in seconds since epoch (Jan 1 1970 GMT)"
+    )
+
+    @classmethod
+    def from_rpc(cls, tx):
+        return cls(
+            in_active_chain=tx["in_active_chain"]
+            if "in_active_chain" in tx.keys()
+            else None,
+            txid=tx["txid"] if "txid" in tx.keys() else "",
+            hash=tx["hash"] if "hash" in tx.keys() else "",
+            size=tx["size"] if "size" in tx.keys() else 0,
+            vsize=tx["vsize"] if "vsize" in tx.keys() else 0,
+            weight=tx["weight"] if "weight" in tx.keys() else 0,
+            version=tx["version"] if "version" in tx.keys() else 0,
+            locktime=tx["locktime"] if "locktime" in tx.keys() else 0,
+            vin=tx["vin"] if "vin" in tx.keys() else [],
+            vout=tx["vout"] if "vout" in tx.keys() else [],
+            blockhash=tx["blockhash"] if "blockhash" in tx.keys() else "",
+            confirmations=tx["confirmations"] if "confirmations" in tx.keys() else 0,
+            blocktime=tx["blocktime"] if "blocktime" in tx.keys() else 0,
+        )
+
+
 # getnetworkinfo
 class NetworkInfo(BaseModel):
     version: int = Query(..., description="The bitcoin core server version")

app/bitcoind/router.py

@@ -3,12 +3,19 @@ from fastapi.params import Depends, Query
 
 from app.auth.auth_bearer import JWTBearer
 from app.bitcoind.docs import blocks_sub_doc, estimate_fee_mode_desc
-from app.bitcoind.models import BlockchainInfo, BtcInfo, FeeEstimationMode, NetworkInfo
+from app.bitcoind.models import (
+    BlockchainInfo,
+    BtcInfo,
+    FeeEstimationMode,
+    NetworkInfo,
+    RawTransaction,
+)
 from app.bitcoind.service import (
     estimate_fee,
     get_blockchain_info,
     get_btc_info,
     get_network_info,
+    get_raw_transaction,
     handle_block_sub,
 )
 from app.bitcoind.utils import bitcoin_rpc
@@ -106,6 +113,27 @@ async def getnetworkinfo():
     return info
 
 
+@router.get(
+    "/get-raw-transaction",
+    name=f"{_PREFIX}.get-raw-transaction",
+    summary="Get information about a raw transaction",
+    description="See documentation on [bitcoincore.org](https://bitcoincore.org/en/doc/22.0.0/rpc/rawtransactions/getrawtransaction/)",
+    response_description="A JSON String with relevant information.",
+    dependencies=[Depends(JWTBearer())],
+    response_model=RawTransaction,
+    responses={
+        400: {"description": "Invalid transaction id"},
+        404: {"description": "No such mempool or blockchain transaction."},
+    },
+)
+async def get_raw_transaction_path(
+    txid: str = Query(
+        ..., min_length=64, max_length=64, description="The transaction id"
+    )
+):
+    return await get_raw_transaction(txid)
+
+
 @router.get(
     "/block-sub",
     name=f"{_PREFIX}.block-sub",

app/bitcoind/service.py

@@ -17,6 +17,7 @@ from app.bitcoind.models import (
     BtcInfo,
     FeeEstimationMode,
     NetworkInfo,
+    RawTransaction,
 )
 from app.bitcoind.utils import bitcoin_config, bitcoin_rpc_async
 
@@ -91,6 +92,21 @@ async def get_network_info() -> NetworkInfo:
     return NetworkInfo.from_rpc(result["result"])
 
 
+async def get_raw_transaction(txid: str) -> RawTransaction:
+    result = await bitcoin_rpc_async("getrawtransaction", [txid, 1])
+
+    if result["error"] == None:
+        return RawTransaction.from_rpc(result["result"])
+
+    if "No such mempool or blockchain transaction." in result["error"]:
+        raise HTTPException(status.HTTP_404_NOT_FOUND, detail=result["error"])
+
+    if "must be of length 64" in result["error"]:
+        raise HTTPException(status.HTTP_404_NOT_FOUND, detail=result["error"])
+
+    raise HTTPException(status.HTTP_500_INTERNAL_SERVER_ERROR, detail=result["error"])
+
+
 async def get_btc_info() -> BtcInfo:
     binfo = await get_blockchain_info()
     ninfo = await get_network_info()

app/bitcoind/utils.py

@@ -1,3 +1,4 @@
+import itertools
 import json
 from types import coroutine
 
@@ -61,17 +62,22 @@ def bitcoin_rpc(method: str, params: list = []) -> requests.Response:
     return requests.post(bitcoin_config.rpc_url, auth=auth, headers=headers, data=data)
 
 
+# https://github.com/python/cpython/blob/3.10/Lib/asyncio/tasks.py#L31
+_generate_rpc_id = itertools.count(1).__next__
+
+
 async def bitcoin_rpc_async(method: str, params: list = []) -> coroutine:
     auth = aiohttp.BasicAuth(bitcoin_config.username, bitcoin_config.pw)
-    headers = {"Content-type": "text/plain"}
+    headers = {"Content-type": "text/json"}
     data = (
         '{"jsonrpc": "2.0", "method": "'
         + method
-        + '", "id":"0", "params":'
+        + f'", "id":{_generate_rpc_id()}, "params":'
         + json.dumps(params)
         + "}"
     )
 
+    # TODO: Refactor this to use Exceptions
     async with aiohttp.ClientSession(auth=auth, headers=headers) as session:
         async with session.post(bitcoin_config.rpc_url, data=data) as resp:
             if resp.status == status.HTTP_200_OK:
@@ -87,6 +93,20 @@ async def bitcoin_rpc_async(method: str, params: list = []) -> coroutine:
                     "status": status.HTTP_403_FORBIDDEN,
                 }
             else:
+                e = await resp.json()
+                m = e["error"]["message"]
+                if e["error"]:
+                    if "No such mempool or blockchain transaction." in m:
+                        return {
+                            "error": "No such mempool or blockchain transaction.",
+                            "status": status.HTTP_404_NOT_FOUND,
+                        }
+                    if "parameter 1 must be of length 64" in m:
+                        return {
+                            "error": m,
+                            "status": status.HTTP_400_BAD_REQUEST,
+                        }
+
                 return {
                     "error": f"Unknown answer from Bitcoin Core. Reason: {resp.reason}",
                     "status": resp.status,