Added /streams/info endpoint

This gives information about available event providers on the API.

backend/moonstream/providers/bugout.py

@@ -35,6 +35,9 @@ class BugoutEventProvider:
     def __init__(
         self,
         event_type: str,
+        description: str,
+        default_time_interval_seconds: int,
+        estimated_events_per_time_interval: float,
         tags: Optional[List[str]] = None,
         batch_size: int = 100,
         timeout: float = 30.0,
@@ -47,6 +50,9 @@ class BugoutEventProvider:
         - timeout: Request timeout for Bugout requests
         """
         self.event_type = event_type
+        self.description = description
+        self.default_time_interval_seconds = default_time_interval_seconds
+        self.estimated_events_per_time_interval = estimated_events_per_time_interval
         self.batch_size = batch_size
         self.timeout = timeout
         if tags is None:
@@ -273,12 +279,23 @@ class EthereumTXPoolProvider(BugoutEventProvider):
     def __init__(
         self,
         event_type: str,
+        description: str,
+        default_time_interval_seconds: int,
+        estimated_events_per_time_interval: float,
         tags: Optional[List[str]] = None,
         batch_size: int = 100,
         timeout: float = 30.0,
     ):
 
-        super().__init__(event_type, tags, batch_size, timeout)
+        super().__init__(
+            event_type=event_type,
+            description=description,
+            default_time_interval_seconds=default_time_interval_seconds,
+            estimated_events_per_time_interval=estimated_events_per_time_interval,
+            tags=tags,
+            batch_size=batch_size,
+            timeout=timeout,
+        )
 
     def parse_filters(
         self, query: StreamQuery, user_subscriptions: Dict[str, List[BugoutResource]]
@@ -304,11 +321,32 @@ class EthereumTXPoolProvider(BugoutEventProvider):
         return subscriptions_filters
 
 
+whalewatch_description = """Event provider for Ethereum whale watch.
+
+Shows the top 10 addresses active on the Ethereum blockchain over the last hour in the following categories:
+1. Number of transactions sent
+2. Number of transactions received
+3. Amount (in WEI) sent
+4. Amount (in WEI) received
+
+To restrict your queries to this provider, add a filter of \"type:ethereum_whalewatch\" to your query (query parameter: \"q\") on the /streams endpoint."""
 whalewatch_provider = BugoutEventProvider(
-    event_type="ethereum_whalewatch", tags=["crawl_type:ethereum_trending"]
+    event_type="ethereum_whalewatch",
+    description=whalewatch_description,
+    default_time_interval_seconds=310,
+    estimated_events_per_time_interval=1,
+    tags=["crawl_type:ethereum_trending"],
 )
 
+ethereum_txpool_description = """Event provider for Ethereum transaction pool.
 
+Shows the latest events (from the previous hour) in the Ethereum transaction pool.
+
+To restrict your queries to this provider, add a filter of \"type:ethereum_txpool\" to your query (query parameter: \"q\") on the /streams endpoint."""
 ethereum_txpool_provider = EthereumTXPoolProvider(
-    event_type="ethereum_txpool", tags=["client:ethereum-txpool-crawler-0"]
+    event_type="ethereum_txpool",
+    description=ethereum_txpool_description,
+    default_time_interval_seconds=5,
+    estimated_events_per_time_interval=50,
+    tags=["client:ethereum-txpool-crawler-0"],
 )

backend/moonstream/providers/ethereum_blockchain.py

@@ -14,7 +14,6 @@ from sqlalchemy.orm import Session, Query
 from sqlalchemy.sql.functions import user
 
 from .. import data
-from ..settings import DEFAULT_STREAM_TIMEINTERVAL
 from ..stream_boundaries import validate_stream_boundary
 from ..stream_queries import StreamQuery
 
@@ -25,6 +24,15 @@ logger.setLevel(logging.WARN)
 
 event_type = "ethereum_blockchain"
 
+description = f"""Event provider for transactions from the Ethereum blockchain.
+
+To restrict your queries to this provider, add a filter of \"type:{event_type}\" to your query (query parameter: \"q\") on the /streams endpoint."""
+
+default_time_interval_seconds: int = 5 * 60
+
+# 200 transactions per block, 4 blocks per minute.
+estimated_events_per_time_interval: float = 5 * 800
+
 
 def validate_subscription(
     subscription_resource_data: data.SubscriptionResourceData,

backend/moonstream/routes/streams.py

@@ -2,7 +2,7 @@
 The Moonstream subscriptions HTTP API
 """
 import logging
-from typing import Dict, List, Optional
+from typing import Any, Dict, List, Optional
 
 from bugout.data import BugoutResource
 from fastapi import FastAPI, Request, Query, Depends
@@ -58,8 +58,9 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
-whitelist_paths: Dict[str, str] = {}
+whitelist_paths: Dict[str, str] = {"/streams/info": "GET"}
 whitelist_paths.update(DOCS_PATHS)
+whitelist_paths.update()
 app.add_middleware(BroodAuthMiddleware, whitelist=whitelist_paths)
 
 
@@ -88,6 +89,19 @@ def get_user_subscriptions(token: str) -> Dict[str, List[BugoutResource]]:
     return user_subscriptions
 
 
+@app.get("/info", tags=["streams"])
+async def info_handler() -> Dict[str, Any]:
+    info = {
+        event_type: {
+            "description": provider.description,
+            "default_time_interval_seconds": provider.default_time_interval_seconds,
+            "estimated_events_per_time_interval": provider.estimated_events_per_time_interval,
+        }
+        for event_type, provider in event_providers.items()
+    }
+    return info
+
+
 @app.get("/", tags=["streams"], response_model=data.GetEventsResponse)
 async def stream_handler(
     request: Request,