upstream()

def upstream(
    node_id: str,
    max_depth: int = 10,
    edge_types: List[str] = None
) -> List[Dict[str, Any]]

from graph.query import QueryEngine

query_engine = QueryEngine(storage)

# Find all services that depend on a database
dependents = query_engine.upstream(
    node_id="database:users-db"
)

print(f"Services affected if users-db goes down: {len(dependents)}")

for dep in dependents:
    print(f"{dep['name']} ({dep['type']}) - distance: {dep['distance']}")

Services affected if users-db goes down: 5

auth-service (service) - distance: 1
payment-api (service) - distance: 1
user-profile-api (service) - distance: 1
api-gateway (service) - distance: 2
web-frontend (application) - distance: 3

# Before making a breaking change to a library
library_id = "library:auth-lib"
consumers = query_engine.upstream(node_id=library_id)

if len(consumers) > 0:
    print(f"WARNING: {len(consumers)} components depend on {library_id}")
    print("\nAffected components:")
    for consumer in consumers:
        print(f"  - {consumer['name']} (distance: {consumer['distance']})")
else:
    print("Safe to modify - no consumers found")

# Only find services that directly DEPEND_ON this database
# (not just USE it for caching)
direct_dependents = query_engine.upstream(
    node_id="database:postgres-main",
    edge_types=["DEPENDS_ON"]
)

print(f"Critical dependents: {len(direct_dependents)}")

# Get only direct consumers (1 hop away)
immediate = query_engine.upstream(
    node_id="service:auth-service",
    max_depth=1
)

print("Direct consumers:")
for node in immediate:
    print(f"  - {node['name']}")

affected = query_engine.upstream(node_id="database:analytics-db")

# Categorize by type
by_type = {}
for node in affected:
    node_type = node['type']
    if node_type not in by_type:
        by_type[node_type] = []
    by_type[node_type].append(node['name'])

print("Impact by type:")
for node_type, names in by_type.items():
    print(f"  {node_type}: {len(names)} affected")
    for name in names[:3]:  # Show first 3
        print(f"    - {name}")