diff --git a/spoolman/api/v1/models.py b/spoolman/api/v1/models.py
index 62ddf3a..4c7797e 100644
--- a/spoolman/api/v1/models.py
+++ b/spoolman/api/v1/models.py
@@ -14,6 +14,7 @@ class Message(BaseModel):
 
 class Vendor(BaseModel):
     id: int = Field(description="Unique internal ID of this vendor.")
+    registered: datetime = Field(description="When the vendor was registered in the database.")
     name: str = Field(max_length=64, description="Vendor name.", example="Polymaker")
     comment: Optional[str] = Field(max_length=1024, description="Free text comment about this vendor.", example="")
 
@@ -22,6 +23,7 @@ class Vendor(BaseModel):
         """Create a new Pydantic vendor object from a database vendor object."""
         return Vendor(
             id=item.id,
+            registered=item.registered,
             name=item.name,
             comment=item.comment,
         )
@@ -29,6 +31,7 @@ class Vendor(BaseModel):
 
 class Filament(BaseModel):
     id: int = Field(description="Unique internal ID of this filament type.")
+    registered: datetime = Field(description="When the filament was registered in the database.")
     name: Optional[str] = Field(
         max_length=64,
         description=(
@@ -72,6 +75,7 @@ class Filament(BaseModel):
         """Create a new Pydantic filament object from a database filament object."""
         return Filament(
             id=item.id,
+            registered=item.registered,
             name=item.name,
             vendor=Vendor.from_db(item.vendor) if item.vendor is not None else None,
             material=item.material,
diff --git a/spoolman/database/models.py b/spoolman/database/models.py
index 6733977..7cda6ce 100644
--- a/spoolman/database/models.py
+++ b/spoolman/database/models.py
@@ -16,6 +16,7 @@ class Vendor(Base):
     __tablename__ = "vendor"
 
     id: Mapped[int] = mapped_column(Integer, primary_key=True, index=True)
+    registered: Mapped[datetime] = mapped_column(default=func.now())
     name: Mapped[str] = mapped_column(String(64))
     comment: Mapped[Optional[str]] = mapped_column(String(1024))
     filaments: Mapped[list["Filament"]] = relationship(back_populates="vendor")
@@ -25,6 +26,7 @@ class Filament(Base):
     __tablename__ = "filament"
 
     id: Mapped[int] = mapped_column(primary_key=True, index=True)
+    registered: Mapped[datetime] = mapped_column(default=func.now())
     name: Mapped[Optional[str]] = mapped_column(String(64))
     vendor_id: Mapped[Optional[int]] = mapped_column(ForeignKey("vendor.id"))
     vendor: Mapped[Optional["Vendor"]] = relationship(back_populates="filaments")