Add mempool.space as fee estimator and remote read devfund pubkey (#1055)

api/logics.py

@@ -9,7 +9,7 @@ from django.utils import timezone
 from api.lightning.node import LNNode
 from api.models import Currency, LNPayment, MarketTick, OnchainPayment, Order
 from api.tasks import send_devfund_donation, send_notification
-from api.utils import validate_onchain_address
+from api.utils import get_minning_fee, validate_onchain_address
 from chat.models import Message
 
 FEE = float(config("FEE"))
@@ -640,10 +640,7 @@ class Logics:
         ):  # Not enough onchain balance to commit for this swap.
             return False
 
-        suggested_mining_fee_rate = LNNode.estimate_fee(
-            amount_sats=preliminary_amount,
-            target_conf=config("SUGGESTED_TARGET_CONF", cast=int, default=2),
-        )["mining_fee_rate"]
+        suggested_mining_fee_rate = get_minning_fee("suggested", preliminary_amount)
 
         # Hardcap mining fee suggested at 1000 sats/vbyte
         if suggested_mining_fee_rate > 1000:
@@ -795,10 +792,7 @@ class Logics:
         num_satoshis = cls.payout_amount(order, user)[1]["invoice_amount"]
         if mining_fee_rate:
             # not a valid mining fee
-            min_mining_fee_rate = LNNode.estimate_fee(
-                amount_sats=num_satoshis,
-                target_conf=config("MINIMUM_TARGET_CONF", cast=int, default=24),
-            )["mining_fee_rate"]
+            min_mining_fee_rate = get_minning_fee("minimum", num_satoshis)
 
             min_mining_fee_rate = max(2, min_mining_fee_rate)
 

api/tasks.py

@@ -98,15 +98,9 @@ def send_devfund_donation(order_id, proceeds, reason):
 
     from api.lightning.node import LNNode
     from api.models import LNPayment, Order
+    from api.utils import get_devfund_pubkey
 
-    if config("NETWORK", cast=str) == "testnet":
-        target_pubkey = (
-            "03ecb271b3e2e36f2b91c92c65bab665e5165f8cdfdada1b5f46cfdd3248c87fd6"
-        )
-    else:
-        target_pubkey = (
-            "02187352cc4b1856b9604e0a79e1bc9b301be7e0c14acbbb8c29f7051d507127d7"
-        )
+    target_pubkey = get_devfund_pubkey(config("NETWORK", cast=str))
 
     order = Order.objects.get(id=order_id)
     coordinator_alias = config("COORDINATOR_ALIAS", cast=str, default="NoAlias")

api/utils.py

@@ -70,6 +70,96 @@ def validate_onchain_address(address):
     return True, None
 
 
+mining_fee = {}
+
+
+@ring.dict(mining_fee, expire=60)  # keeps in cache for 60 seconds
+def get_minning_fee(priority: str, preliminary_amount: int) -> int:
+    """
+    priority: (str) 'suggested' | 'minimum'
+    Fetches suggested and minimum mining fee rates from mempool.space
+    uses LND/CLN fee estimator as fallback.
+
+    mempool.space response object:
+    {
+        fastestFee: 1,
+        halfHourFee: 1,
+        hourFee: 1,
+        economyFee: 1,
+        minimumFee: 1
+    }
+    Where 'suggested' is 'fastestFee' and 'minimum' is 'economyFee'
+    """
+
+    from api.lightning.node import LNNode
+
+    session = get_session()
+    mempool_url = (
+        "http://mempoolhqx4isw62xs7abwphsq7ldayuidyx2v2oethdhhj6mlo2r6ad.onion"
+        if USE_TOR
+        else "https://mempool.space"
+    )
+    api_path = "/api/v1/fees/recommended"
+
+    try:
+        response = session.get(mempool_url + api_path)
+        response.raise_for_status()  # Raises stored HTTPError, if one occurred
+        data = response.json()
+        if priority == "suggested":
+            value = data.get("fastestFee")
+        elif priority == "minimum":
+            value = data.get("economyFee")
+        else:
+            raise Exception(
+                "an error occurred",
+                "unexpected value for mining fee priority",
+                priority,
+            )
+
+    except Exception:
+        # Fetch mining fee from LND/CLN instance
+        if priority == "suggested":
+            target_conf = config("SUGGESTED_TARGET_CONF", cast=int, default=2)
+        if priority == "minimum":
+            target_conf = config("MINIMUM_TARGET_CONF", cast=int, default=24)
+
+        value = LNNode.estimate_fee(
+            amount_sats=preliminary_amount,
+            target_conf=target_conf,
+        )["mining_fee_rate"]
+
+    return value
+
+
+devfund_pubkey = {}
+
+
+@ring.dict(devfund_pubkey, expire=3600)  # keeps in cache for 3600 seconds
+def get_devfund_pubkey(network: str) -> str:
+    """
+    network: (str) "mainnet" | "testnet";
+    Fetches devfund pubkey from `main` branch in the repository
+    fallback to hardcoded pubkey
+    """
+
+    session = get_session()
+    url = "https://raw.githubusercontent.com/RoboSats/robosats/main/devfund_pubkey.json"
+    # hardcoded fallback
+    mainnet = "02187352cc4b1856b9604e0a79e1bc9b301be7e0c14acbbb8c29f7051d507127d7"
+    testnet = "03ecb271b3e2e36f2b91c92c65bab665e5165f8cdfdada1b5f46cfdd3248c87fd6"
+
+    try:
+        response = session.get(url)
+        response.raise_for_status()  # Raises stored HTTPError, if one occurred
+        value = response.json().get(network)
+        if len(value) == 66:
+            return value
+    except Exception as e:
+        print(e)
+
+    return mainnet if network == "mainnet" else testnet
+
+
 market_cache = {}
 
 

devfund_pubkey.json

@@ -0,0 +1,4 @@
+{
+  "mainnet": "02187352cc4b1856b9604e0a79e1bc9b301be7e0c14acbbb8c29f7051d507127d7",
+  "testnet": "03ecb271b3e2e36f2b91c92c65bab665e5165f8cdfdada1b5f46cfdd3248c87fd6"
+}