diff --git a/src/miv_simulator/config/__init__.py b/src/miv_simulator/config/__init__.py
index 1a09bb3..e7c5081 100644
--- a/src/miv_simulator/config/__init__.py
+++ b/src/miv_simulator/config/__init__.py
@@ -46,6 +46,9 @@ class SynapseMechanismsDef(IntEnum):
     NMDA = 30
 
 
+SynapseMechanismsLiteral = Literal["AMPA", "GABA_A", "GABA_B", "NMDA"]
+
+
 class LayersDef(IntEnum):
     default = -1
     Hilus = 0
@@ -145,11 +148,12 @@ def __getitem__(self, item):
 
 
 class Mechanism(BaseModel):
-    tau_rise: float = None
-    tau_decay: float = None
-    e: int = None
     g_unit: float
     weight: float
+    tau_rise: Optional[float] = None
+    tau_decay: Optional[float] = None
+    e: Optional[int] = None
+    
 
 
 class Synapse(BaseModel):
@@ -157,7 +161,7 @@ class Synapse(BaseModel):
     sections: conlist(SWCTypesDefOrStr)
     layers: conlist(LayersDefOrStr)
     proportions: conlist(float)
-    mechanisms: Dict[SynapseMechanismsDefOrStr, Mechanism]
+    mechanisms: Dict[SynapseMechanismsLiteral, Mechanism]
 
 
 def _origin_value_to_callable(value: Union[str, float]) -> Callable:
@@ -211,9 +215,7 @@ class AxonExtent(BaseModel):
     offset: Tuple[float, float]
 
 
-AxonExtents = Dict[PopulationsDefOrStr, Dict[LayerName, AxonExtent]]
-
-# Composed
+AxonExtents = Dict[PopulationsLiteral, Dict[LayerName, AxonExtent]]
 
 
 def probabilities_sum_to_one(x):
diff --git a/src/miv_simulator/connections.py b/src/miv_simulator/connections.py
index 0ea4ce4..bdcdf71 100644
--- a/src/miv_simulator/connections.py
+++ b/src/miv_simulator/connections.py
@@ -611,7 +611,7 @@ def generate_uv_distance_connections(
             projection_config[source_population].layers,
             projection_config[source_population].sections,
             projection_config[source_population].proportions,
-            projection_config[source_population].contacts,
+            projection_config[source_population].get("contacts", None),
         )
         for source_population in source_populations
     }
diff --git a/src/miv_simulator/interface/create_network.py b/src/miv_simulator/interface/create_network.py
index fef31b0..e54c12a 100644
--- a/src/miv_simulator/interface/create_network.py
+++ b/src/miv_simulator/interface/create_network.py
@@ -123,8 +123,9 @@ def distance_connections(self, version: VersionType = None):
             "miv_simulator.interface.distance_connections",
             [
                 {
-                    "blueprint": self.config.blueprint,
-                    "coordinates": self.output_filepath,
+                    "filepath": self.output_filepath,
+                    "synapses": self.config.synapses,
+                    "coordinates_namespace": self.config.coordinate_namespace,
                 }
             ]
             + normversion(version),
diff --git a/src/miv_simulator/interface/distance_connections.py b/src/miv_simulator/interface/distance_connections.py
index 05ef336..58c3dcb 100644
--- a/src/miv_simulator/interface/distance_connections.py
+++ b/src/miv_simulator/interface/distance_connections.py
@@ -5,23 +5,24 @@
 from machinable import Component
 from pydantic import BaseModel, Field
 from miv_simulator import config
-from typing import Optional
+from typing import Optional, Dict
 from miv_simulator.simulator import distance_connections
+from miv_simulator.utils import from_yaml
 
 
 class DistanceConnections(Component):
     class Config(BaseModel):
         filepath: str = Field("???")
         forest_filepath: str = Field("???")
+        axon_extents: config.AxonExtents = Field("???")
+        synapses: config.Synapses = Field("???")
         include_forest_populations: Optional[list] = None
-        synapses: config.Synapses = {}
-        connection_extents: config.ConnectionExtents = {}
         template_path: str = "./templates"
         use_coreneuron: bool = False
         dt: float = 0.025
-        tstop: float = (0.0,)
+        tstop: float = 0.0
         celsius: Optional[float] = 35.0
-        connectivity_namespace: str = "Connectivity"
+        connectivity_namespace: str = "Connections"
         coordinates_namespace: str = "Coordinates"
         synapses_namespace: str = "Synapse Attributes"
         distances_namespace: str = "Arc Distances"
@@ -33,6 +34,9 @@ class Config(BaseModel):
         write_size: int = 1
         ranks_: int = 8
 
+    def config_from_file(self, filename: str) -> Dict:
+        return from_yaml(filename)
+
     @property
     def output_filepath(self):
         return self.local_directory("connectivity.h5")
@@ -44,7 +48,7 @@ def __call__(self):
             forest_filepath=self.config.forest_filepath,
             include_forest_populations=self.config.include_forest_populations,
             synapses=self.config.synapses,
-            connection_extents=self.config.connection_extents,
+            axon_extents=self.config.axon_extents,
             template_path=self.config.template_path,
             use_coreneuron=self.config.use_coreneuron,
             dt=self.config.dt,
@@ -61,4 +65,5 @@ def __call__(self):
             cache_size=self.config.cache_size,
             write_size=self.config.write_size,
             dry_run=False,
+            seeds=self.seed
         )
diff --git a/src/miv_simulator/simulator/generate_distance_connections.py b/src/miv_simulator/simulator/generate_distance_connections.py
index a28ef3b..4c6552b 100644
--- a/src/miv_simulator/simulator/generate_distance_connections.py
+++ b/src/miv_simulator/simulator/generate_distance_connections.py
@@ -241,8 +241,8 @@ def distance_connections(
             )
 
         if seeds is None or isinstance(seeds, int):
-            r = random.Random(seed=seeds)
-            seeds = [r.randint(0, 2**32 - 1) for r in range(3)]
+            r = random.Random(seeds)
+            seeds = [r.randint(0, 2**32 - 1) for _ in range(3)]
 
         populations_dict = config.PopulationsDef.__members__
         generate_uv_distance_connections(