Remove tag system, use versions only for artifact references

Tags were mutable aliases that caused confusion alongside the immutable
version system. This removes tags entirely, keeping only PackageVersion
for artifact references.

Changes:
- Remove tags and tag_history tables (migration 012)
- Remove Tag model, TagRepository, and 6 tag API endpoints
- Update cache system to create versions instead of tags
- Update frontend to display versions instead of tags
- Remove tag-related schemas and types
- Update artifact cleanup service for version-based ref_count

backend/app/dependencies.py

@@ -28,7 +28,6 @@ from .models import (
     Project,
     Package,
     Artifact,
-    Tag,
     ArtifactDependency,
     PackageVersion,
 )
@@ -153,26 +152,20 @@ def parse_ensure_file(content: bytes) -> EnsureFileContent:
         project = dep.get('project')
         package = dep.get('package')
         version = dep.get('version')
-        tag = dep.get('tag')
 
         if not project:
             raise InvalidEnsureFileError(f"Dependency {i} missing 'project'")
         if not package:
             raise InvalidEnsureFileError(f"Dependency {i} missing 'package'")
-        if not version and not tag:
+        if not version:
             raise InvalidEnsureFileError(
-                f"Dependency {i} must have either 'version' or 'tag'"
-            )
-        if version and tag:
-            raise InvalidEnsureFileError(
-                f"Dependency {i} cannot have both 'version' and 'tag'"
+                f"Dependency {i} must have 'version'"
             )
 
         dependencies.append(EnsureFileDependency(
             project=project,
             package=package,
             version=version,
-            tag=tag,
         ))
 
     return EnsureFileContent(dependencies=dependencies)
@@ -226,7 +219,6 @@ def store_dependencies(
             dependency_project=dep.project,
             dependency_package=dep.package,
             version_constraint=dep.version,
-            tag_constraint=dep.tag,
         )
         db.add(artifact_dep)
         created.append(artifact_dep)
@@ -292,26 +284,21 @@ def get_reverse_dependencies(
         if not artifact:
             continue
 
-        # Find which package this artifact belongs to via tags or versions
-        tag = db.query(Tag).filter(Tag.artifact_id == dep.artifact_id).first()
-        if tag:
-            pkg = db.query(Package).filter(Package.id == tag.package_id).first()
+        # Find which package this artifact belongs to via versions
+        version_record = db.query(PackageVersion).filter(
+            PackageVersion.artifact_id == dep.artifact_id,
+        ).first()
+        if version_record:
+            pkg = db.query(Package).filter(Package.id == version_record.package_id).first()
             if pkg:
                 proj = db.query(Project).filter(Project.id == pkg.project_id).first()
                 if proj:
-                    # Get version if available
-                    version_record = db.query(PackageVersion).filter(
-                        PackageVersion.artifact_id == dep.artifact_id,
-                        PackageVersion.package_id == pkg.id,
-                    ).first()
-
                     dependents.append(DependentInfo(
                         artifact_id=dep.artifact_id,
                         project=proj.name,
                         package=pkg.name,
-                        version=version_record.version if version_record else None,
-                        constraint_type="version" if dep.version_constraint else "tag",
-                        constraint_value=dep.version_constraint or dep.tag_constraint,
+                        version=version_record.version,
+                        constraint_value=dep.version_constraint,
                     ))
 
     total_pages = (total + limit - 1) // limit
@@ -423,8 +410,7 @@ def _resolve_dependency_to_artifact(
     db: Session,
     project_name: str,
     package_name: str,
-    version: Optional[str],
-    tag: Optional[str],
+    version: str,
 ) -> Optional[Tuple[str, str, int]]:
     """
     Resolve a dependency constraint to an artifact ID.
@@ -432,7 +418,6 @@ def _resolve_dependency_to_artifact(
     Supports:
     - Exact version matching (e.g., '1.2.3')
     - Version constraints (e.g., '>=1.9', '<2.0,>=1.5')
-    - Tag matching
     - Wildcard ('*' for any version)
 
     Args:
@@ -440,10 +425,9 @@ def _resolve_dependency_to_artifact(
         project_name: Project name
         package_name: Package name
         version: Version or version constraint
-        tag: Tag constraint
 
     Returns:
-        Tuple of (artifact_id, resolved_version_or_tag, size) or None if not found
+        Tuple of (artifact_id, resolved_version, size) or None if not found
     """
     # Get project and package
     project = db.query(Project).filter(Project.name == project_name).first()
@@ -457,50 +441,24 @@ def _resolve_dependency_to_artifact(
     if not package:
         return None
 
-    if version:
-        # Check if this is a version constraint (>=, <, etc.) or exact version
-        if _is_version_constraint(version):
-            result = _resolve_version_constraint(db, package, version)
-            if result:
-                return result
-        else:
-            # Look up by exact version
-            pkg_version = db.query(PackageVersion).filter(
-                PackageVersion.package_id == package.id,
-                PackageVersion.version == version,
-            ).first()
-            if pkg_version:
-                artifact = db.query(Artifact).filter(
-                    Artifact.id == pkg_version.artifact_id
-                ).first()
-                if artifact:
-                    return (artifact.id, version, artifact.size)
-
-        # Also check if there's a tag with this exact name
-        tag_record = db.query(Tag).filter(
-            Tag.package_id == package.id,
-            Tag.name == version,
+    # Check if this is a version constraint (>=, <, etc.) or exact version
+    if _is_version_constraint(version):
+        result = _resolve_version_constraint(db, package, version)
+        if result:
+            return result
+    else:
+        # Look up by exact version
+        pkg_version = db.query(PackageVersion).filter(
+            PackageVersion.package_id == package.id,
+            PackageVersion.version == version,
         ).first()
-        if tag_record:
+        if pkg_version:
             artifact = db.query(Artifact).filter(
-                Artifact.id == tag_record.artifact_id
+                Artifact.id == pkg_version.artifact_id
             ).first()
             if artifact:
                 return (artifact.id, version, artifact.size)
 
-    if tag:
-        # Look up by tag
-        tag_record = db.query(Tag).filter(
-            Tag.package_id == package.id,
-            Tag.name == tag,
-        ).first()
-        if tag_record:
-            artifact = db.query(Artifact).filter(
-                Artifact.id == tag_record.artifact_id
-            ).first()
-            if artifact:
-                return (artifact.id, tag, artifact.size)
-
     return None
 
 
@@ -560,9 +518,9 @@ def _detect_package_cycle(
             Package.name == package_name,
         ).first()
         if package:
-            # Find all artifacts in this package via tags
-            tags = db.query(Tag).filter(Tag.package_id == package.id).all()
-            artifact_ids = {t.artifact_id for t in tags}
+            # Find all artifacts in this package via versions
+            versions = db.query(PackageVersion).filter(PackageVersion.package_id == package.id).all()
+            artifact_ids = {v.artifact_id for v in versions}
 
             # Get dependencies from all artifacts in this package
             for artifact_id in artifact_ids:
@@ -605,8 +563,8 @@ def check_circular_dependencies(
         db: Database session
         artifact_id: The artifact that will have these dependencies
         new_dependencies: Dependencies to be added
-        project_name: Project name (optional, will try to look up from tag if not provided)
-        package_name: Package name (optional, will try to look up from tag if not provided)
+        project_name: Project name (optional, will try to look up from version if not provided)
+        package_name: Package name (optional, will try to look up from version if not provided)
 
     Returns:
         Cycle path if detected, None otherwise
@@ -615,17 +573,19 @@ def check_circular_dependencies(
     if project_name and package_name:
         current_path = f"{project_name}/{package_name}"
     else:
-        # Try to look up from tag
+        # Try to look up from version
         artifact = db.query(Artifact).filter(Artifact.id == artifact_id).first()
         if not artifact:
             return None
 
-        # Find package for this artifact
-        tag = db.query(Tag).filter(Tag.artifact_id == artifact_id).first()
-        if not tag:
+        # Find package for this artifact via version
+        version_record = db.query(PackageVersion).filter(
+            PackageVersion.artifact_id == artifact_id
+        ).first()
+        if not version_record:
             return None
 
-        package = db.query(Package).filter(Package.id == tag.package_id).first()
+        package = db.query(Package).filter(Package.id == version_record.package_id).first()
         if not package:
             return None
 
@@ -682,7 +642,7 @@ def resolve_dependencies(
         db: Database session
         project_name: Project name
         package_name: Package name
-        ref: Tag or version reference
+        ref: Version reference (or artifact:hash)
         base_url: Base URL for download URLs
 
     Returns:
@@ -715,7 +675,7 @@ def resolve_dependencies(
         root_version = artifact_id[:12]  # Use short hash as version display
         root_size = artifact.size
     else:
-        # Try to find artifact by tag or version
+        # Try to find artifact by version
         resolved = _resolve_dependency_to_artifact(
             db, project_name, package_name, ref, ref
         )
@@ -820,12 +780,11 @@ def resolve_dependencies(
                 dep.dependency_project,
                 dep.dependency_package,
                 dep.version_constraint,
-                dep.tag_constraint,
             )
 
             if not resolved_dep:
                 # Dependency not cached on server - track as missing but continue
-                constraint = dep.version_constraint or dep.tag_constraint
+                constraint = dep.version_constraint
                 missing_dependencies.append(MissingDependency(
                     project=dep.dependency_project,
                     package=dep.dependency_package,

backend/app/models.py

@@ -71,7 +71,6 @@ class Package(Base):
     )
 
     project = relationship("Project", back_populates="packages")
-    tags = relationship("Tag", back_populates="package", cascade="all, delete-orphan")
     uploads = relationship(
         "Upload", back_populates="package", cascade="all, delete-orphan"
     )
@@ -120,7 +119,6 @@ class Artifact(Base):
     ref_count = Column(Integer, default=1)
     s3_key = Column(String(1024), nullable=False)
 
-    tags = relationship("Tag", back_populates="artifact")
     uploads = relationship("Upload", back_populates="artifact")
     versions = relationship("PackageVersion", back_populates="artifact")
     dependencies = relationship(
@@ -151,65 +149,6 @@ class Artifact(Base):
     )
 
 
-class Tag(Base):
-    __tablename__ = "tags"
-
-    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
-    package_id = Column(
-        UUID(as_uuid=True),
-        ForeignKey("packages.id", ondelete="CASCADE"),
-        nullable=False,
-    )
-    name = Column(String(255), nullable=False)
-    artifact_id = Column(String(64), ForeignKey("artifacts.id"), nullable=False)
-    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
-    updated_at = Column(
-        DateTime(timezone=True), default=datetime.utcnow, onupdate=datetime.utcnow
-    )
-    created_by = Column(String(255), nullable=False)
-
-    package = relationship("Package", back_populates="tags")
-    artifact = relationship("Artifact", back_populates="tags")
-    history = relationship(
-        "TagHistory", back_populates="tag", cascade="all, delete-orphan"
-    )
-
-    __table_args__ = (
-        Index("idx_tags_package_id", "package_id"),
-        Index("idx_tags_artifact_id", "artifact_id"),
-        Index(
-            "idx_tags_package_name", "package_id", "name", unique=True
-        ),  # Composite unique index
-        Index(
-            "idx_tags_package_created_at", "package_id", "created_at"
-        ),  # For recent tags queries
-    )
-
-
-class TagHistory(Base):
-    __tablename__ = "tag_history"
-
-    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
-    tag_id = Column(
-        UUID(as_uuid=True), ForeignKey("tags.id", ondelete="CASCADE"), nullable=False
-    )
-    old_artifact_id = Column(String(64), ForeignKey("artifacts.id"))
-    new_artifact_id = Column(String(64), ForeignKey("artifacts.id"), nullable=False)
-    change_type = Column(String(20), nullable=False, default="update")
-    changed_at = Column(DateTime(timezone=True), default=datetime.utcnow)
-    changed_by = Column(String(255), nullable=False)
-
-    tag = relationship("Tag", back_populates="history")
-
-    __table_args__ = (
-        Index("idx_tag_history_tag_id", "tag_id"),
-        Index("idx_tag_history_changed_at", "changed_at"),
-        CheckConstraint(
-            "change_type IN ('create', 'update', 'delete')", name="check_change_type"
-        ),
-    )
-
-
 class PackageVersion(Base):
     """Immutable version record for a package-artifact relationship.
 
@@ -249,7 +188,7 @@ class Upload(Base):
     artifact_id = Column(String(64), ForeignKey("artifacts.id"), nullable=False)
     package_id = Column(UUID(as_uuid=True), ForeignKey("packages.id"), nullable=False)
     original_name = Column(String(1024))
-    tag_name = Column(String(255))  # Tag assigned during upload
+    version = Column(String(255))  # Version assigned during upload
     user_agent = Column(String(512))  # Client identification
     duration_ms = Column(Integer)  # Upload timing in milliseconds
     deduplicated = Column(Boolean, default=False)  # Whether artifact was deduplicated
@@ -524,8 +463,8 @@ class PackageHistory(Base):
 class ArtifactDependency(Base):
     """Dependency declared by an artifact on another package.
 
-    Each artifact can declare dependencies on other packages, specifying either
-    an exact version or a tag. This enables recursive dependency resolution.
+    Each artifact can declare dependencies on other packages, specifying a version.
+    This enables recursive dependency resolution.
     """
 
     __tablename__ = "artifact_dependencies"
@@ -538,20 +477,13 @@ class ArtifactDependency(Base):
     )
     dependency_project = Column(String(255), nullable=False)
     dependency_package = Column(String(255), nullable=False)
-    version_constraint = Column(String(255), nullable=True)
-    tag_constraint = Column(String(255), nullable=True)
+    version_constraint = Column(String(255), nullable=False)
     created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
 
     # Relationship to the artifact that declares this dependency
     artifact = relationship("Artifact", back_populates="dependencies")
 
     __table_args__ = (
-        # Exactly one of version_constraint or tag_constraint must be set
-        CheckConstraint(
-            "(version_constraint IS NOT NULL AND tag_constraint IS NULL) OR "
-            "(version_constraint IS NULL AND tag_constraint IS NOT NULL)",
-            name="check_constraint_type",
-        ),
         # Each artifact can only depend on a specific project/package once
         Index(
             "idx_artifact_dependencies_artifact_id",

backend/app/purge_seed_data.py

@@ -12,7 +12,6 @@ from .models import (
     Project,
     Package,
     Artifact,
-    Tag,
     Upload,
     PackageVersion,
     ArtifactDependency,
@@ -60,7 +59,6 @@ def purge_seed_data(db: Session) -> dict:
 
     results = {
         "dependencies_deleted": 0,
-        "tags_deleted": 0,
         "versions_deleted": 0,
         "uploads_deleted": 0,
         "artifacts_deleted": 0,
@@ -103,15 +101,7 @@ def purge_seed_data(db: Session) -> dict:
         results["dependencies_deleted"] = count
         logger.info(f"Deleted {count} artifact dependencies")
 
-    # 2. Delete tags
-    if seed_package_ids:
-        count = db.query(Tag).filter(Tag.package_id.in_(seed_package_ids)).delete(
-            synchronize_session=False
-        )
-        results["tags_deleted"] = count
-        logger.info(f"Deleted {count} tags")
-
-    # 3. Delete package versions
+    # 2. Delete package versions
     if seed_package_ids:
         count = db.query(PackageVersion).filter(
             PackageVersion.package_id.in_(seed_package_ids)
@@ -119,7 +109,7 @@ def purge_seed_data(db: Session) -> dict:
         results["versions_deleted"] = count
         logger.info(f"Deleted {count} package versions")
 
-    # 4. Delete uploads
+    # 3. Delete uploads
     if seed_package_ids:
         count = db.query(Upload).filter(Upload.package_id.in_(seed_package_ids)).delete(
             synchronize_session=False
@@ -127,7 +117,7 @@ def purge_seed_data(db: Session) -> dict:
         results["uploads_deleted"] = count
         logger.info(f"Deleted {count} uploads")
 
-    # 5. Delete S3 objects for seed artifacts
+    # 4. Delete S3 objects for seed artifacts
     if seed_artifact_ids:
         seed_artifacts = db.query(Artifact).filter(Artifact.id.in_(seed_artifact_ids)).all()
         for artifact in seed_artifacts:
@@ -139,8 +129,8 @@ def purge_seed_data(db: Session) -> dict:
                     logger.warning(f"Failed to delete S3 object {artifact.s3_key}: {e}")
         logger.info(f"Deleted {results['s3_objects_deleted']} S3 objects")
 
-    # 6. Delete artifacts (only those with ref_count that would be 0 after our deletions)
-    # Since we deleted all tags/versions pointing to these artifacts, we can delete them
+    # 5. Delete artifacts (only those with ref_count that would be 0 after our deletions)
+    # Since we deleted all versions pointing to these artifacts, we can delete them
     if seed_artifact_ids:
         count = db.query(Artifact).filter(Artifact.id.in_(seed_artifact_ids)).delete(
             synchronize_session=False
@@ -148,7 +138,7 @@ def purge_seed_data(db: Session) -> dict:
         results["artifacts_deleted"] = count
         logger.info(f"Deleted {count} artifacts")
 
-    # 7. Delete packages
+    # 6. Delete packages
     if seed_package_ids:
         count = db.query(Package).filter(Package.id.in_(seed_package_ids)).delete(
             synchronize_session=False
@@ -156,7 +146,7 @@ def purge_seed_data(db: Session) -> dict:
         results["packages_deleted"] = count
         logger.info(f"Deleted {count} packages")
 
-    # 8. Delete access permissions for seed projects
+    # 7. Delete access permissions for seed projects
     if seed_project_ids:
         count = db.query(AccessPermission).filter(
             AccessPermission.project_id.in_(seed_project_ids)
@@ -164,14 +154,14 @@ def purge_seed_data(db: Session) -> dict:
         results["permissions_deleted"] = count
         logger.info(f"Deleted {count} access permissions")
 
-    # 9. Delete seed projects
+    # 8. Delete seed projects
     count = db.query(Project).filter(Project.name.in_(SEED_PROJECT_NAMES)).delete(
         synchronize_session=False
     )
     results["projects_deleted"] = count
     logger.info(f"Deleted {count} projects")
 
-    # 10. Find and delete seed team
+    # 9. Find and delete seed team
     seed_team = db.query(Team).filter(Team.slug == SEED_TEAM_SLUG).first()
     if seed_team:
         # Delete team memberships first
@@ -186,7 +176,7 @@ def purge_seed_data(db: Session) -> dict:
         results["teams_deleted"] = 1
         logger.info(f"Deleted team: {SEED_TEAM_SLUG}")
 
-    # 11. Delete seed users (but NOT admin)
+    # 10. Delete seed users (but NOT admin)
     seed_users = db.query(User).filter(User.username.in_(SEED_USERNAMES)).all()
     for user in seed_users:
         # Delete any remaining team memberships for this user

backend/app/pypi_proxy.py

@@ -20,7 +20,7 @@ from fastapi.responses import StreamingResponse, HTMLResponse
 from sqlalchemy.orm import Session
 
 from .database import get_db
-from .models import UpstreamSource, CachedUrl, Artifact, Project, Package, Tag, PackageVersion
+from .models import UpstreamSource, CachedUrl, Artifact, Project, Package, PackageVersion
 from .storage import S3Storage, get_storage
 from .config import get_env_upstream_sources
 
@@ -646,20 +646,6 @@ async def pypi_download_file(
             db.add(package)
             db.flush()
 
-        # Create tag with filename
-        existing_tag = db.query(Tag).filter(
-            Tag.package_id == package.id,
-            Tag.name == filename,
-        ).first()
-        if not existing_tag:
-            tag = Tag(
-                package_id=package.id,
-                name=filename,
-                artifact_id=sha256,
-                created_by="pypi-proxy",
-            )
-            db.add(tag)
-
         # Extract and create version
         # Only create version for actual package files, not .metadata files
         version = _extract_pypi_version(filename)

backend/app/repositories/__init__.py

@@ -9,7 +9,6 @@ from .base import BaseRepository
 from .project import ProjectRepository
 from .package import PackageRepository
 from .artifact import ArtifactRepository
-from .tag import TagRepository
 from .upload import UploadRepository
 
 __all__ = [
@@ -17,6 +16,5 @@ __all__ = [
     "ProjectRepository",
     "PackageRepository",
     "ArtifactRepository",
-    "TagRepository",
     "UploadRepository",
 ]

backend/app/repositories/artifact.py

@@ -8,7 +8,7 @@ from sqlalchemy import func, or_
 from uuid import UUID
 
 from .base import BaseRepository
-from ..models import Artifact, Tag, Upload, Package, Project
+from ..models import Artifact, PackageVersion, Upload, Package, Project
 
 
 class ArtifactRepository(BaseRepository[Artifact]):
@@ -77,14 +77,14 @@ class ArtifactRepository(BaseRepository[Artifact]):
             .all()
         )
 
-    def get_artifacts_without_tags(self, limit: int = 100) -> List[Artifact]:
-        """Get artifacts that have no tags pointing to them."""
-        # Subquery to find artifact IDs that have tags
-        tagged_artifacts = self.db.query(Tag.artifact_id).distinct().subquery()
+    def get_artifacts_without_versions(self, limit: int = 100) -> List[Artifact]:
+        """Get artifacts that have no versions pointing to them."""
+        # Subquery to find artifact IDs that have versions
+        versioned_artifacts = self.db.query(PackageVersion.artifact_id).distinct().subquery()
 
         return (
             self.db.query(Artifact)
-            .filter(~Artifact.id.in_(tagged_artifacts))
+            .filter(~Artifact.id.in_(versioned_artifacts))
             .limit(limit)
             .all()
         )
@@ -115,34 +115,34 @@ class ArtifactRepository(BaseRepository[Artifact]):
 
         return artifacts, total
 
-    def get_referencing_tags(self, artifact_id: str) -> List[Tuple[Tag, Package, Project]]:
-        """Get all tags referencing this artifact with package and project info."""
+    def get_referencing_versions(self, artifact_id: str) -> List[Tuple[PackageVersion, Package, Project]]:
+        """Get all versions referencing this artifact with package and project info."""
         return (
-            self.db.query(Tag, Package, Project)
-            .join(Package, Tag.package_id == Package.id)
+            self.db.query(PackageVersion, Package, Project)
+            .join(Package, PackageVersion.package_id == Package.id)
             .join(Project, Package.project_id == Project.id)
-            .filter(Tag.artifact_id == artifact_id)
+            .filter(PackageVersion.artifact_id == artifact_id)
             .all()
         )
 
-    def search(self, query_str: str, limit: int = 10) -> List[Tuple[Tag, Artifact, str, str]]:
+    def search(self, query_str: str, limit: int = 10) -> List[Tuple[PackageVersion, Artifact, str, str]]:
         """
-        Search artifacts by tag name or original filename.
-        Returns (tag, artifact, package_name, project_name) tuples.
+        Search artifacts by version or original filename.
+        Returns (version, artifact, package_name, project_name) tuples.
         """
         search_lower = query_str.lower()
         return (
-            self.db.query(Tag, Artifact, Package.name, Project.name)
-            .join(Artifact, Tag.artifact_id == Artifact.id)
-            .join(Package, Tag.package_id == Package.id)
+            self.db.query(PackageVersion, Artifact, Package.name, Project.name)
+            .join(Artifact, PackageVersion.artifact_id == Artifact.id)
+            .join(Package, PackageVersion.package_id == Package.id)
             .join(Project, Package.project_id == Project.id)
             .filter(
                 or_(
-                    func.lower(Tag.name).contains(search_lower),
+                    func.lower(PackageVersion.version).contains(search_lower),
                     func.lower(Artifact.original_name).contains(search_lower)
                 )
             )
-            .order_by(Tag.name)
+            .order_by(PackageVersion.version)
             .limit(limit)
             .all()
         )

backend/app/repositories/package.py

@@ -8,7 +8,7 @@ from sqlalchemy import func, or_, asc, desc
 from uuid import UUID
 
 from .base import BaseRepository
-from ..models import Package, Project, Tag, Upload, Artifact
+from ..models import Package, Project, PackageVersion, Upload, Artifact
 
 
 class PackageRepository(BaseRepository[Package]):
@@ -136,10 +136,10 @@ class PackageRepository(BaseRepository[Package]):
         return self.update(package, **updates)
 
     def get_stats(self, package_id: UUID) -> dict:
-        """Get package statistics (tag count, artifact count, total size)."""
-        tag_count = (
-            self.db.query(func.count(Tag.id))
-            .filter(Tag.package_id == package_id)
+        """Get package statistics (version count, artifact count, total size)."""
+        version_count = (
+            self.db.query(func.count(PackageVersion.id))
+            .filter(PackageVersion.package_id == package_id)
             .scalar() or 0
         )
 
@@ -154,7 +154,7 @@ class PackageRepository(BaseRepository[Package]):
         )
 
         return {
-            "tag_count": tag_count,
+            "version_count": version_count,
             "artifact_count": artifact_stats[0] if artifact_stats else 0,
             "total_size": artifact_stats[1] if artifact_stats else 0,
         }

backend/app/repositories/tag.py

@@ -1,168 +0,0 @@
-"""
-Tag repository for data access operations.
-"""
-
-from typing import Optional, List, Tuple
-from sqlalchemy.orm import Session
-from sqlalchemy import func, or_, asc, desc
-from uuid import UUID
-
-from .base import BaseRepository
-from ..models import Tag, TagHistory, Artifact, Package, Project
-
-
-class TagRepository(BaseRepository[Tag]):
-    """Repository for Tag entity operations."""
-
-    model = Tag
-
-    def get_by_name(self, package_id: UUID, name: str) -> Optional[Tag]:
-        """Get tag by name within a package."""
-        return (
-            self.db.query(Tag)
-            .filter(Tag.package_id == package_id, Tag.name == name)
-            .first()
-        )
-
-    def get_with_artifact(self, package_id: UUID, name: str) -> Optional[Tuple[Tag, Artifact]]:
-        """Get tag with its artifact."""
-        return (
-            self.db.query(Tag, Artifact)
-            .join(Artifact, Tag.artifact_id == Artifact.id)
-            .filter(Tag.package_id == package_id, Tag.name == name)
-            .first()
-        )
-
-    def exists_by_name(self, package_id: UUID, name: str) -> bool:
-        """Check if tag with name exists in package."""
-        return self.db.query(
-            self.db.query(Tag)
-            .filter(Tag.package_id == package_id, Tag.name == name)
-            .exists()
-        ).scalar()
-
-    def list_by_package(
-        self,
-        package_id: UUID,
-        page: int = 1,
-        limit: int = 20,
-        search: Optional[str] = None,
-        sort: str = "name",
-        order: str = "asc",
-    ) -> Tuple[List[Tuple[Tag, Artifact]], int]:
-        """
-        List tags in a package with artifact metadata.
-
-        Returns tuple of ((tag, artifact) tuples, total_count).
-        """
-        query = (
-            self.db.query(Tag, Artifact)
-            .join(Artifact, Tag.artifact_id == Artifact.id)
-            .filter(Tag.package_id == package_id)
-        )
-
-        # Apply search filter (tag name or artifact original filename)
-        if search:
-            search_lower = search.lower()
-            query = query.filter(
-                or_(
-                    func.lower(Tag.name).contains(search_lower),
-                    func.lower(Artifact.original_name).contains(search_lower)
-                )
-            )
-
-        # Get total count
-        total = query.count()
-
-        # Apply sorting
-        sort_columns = {
-            "name": Tag.name,
-            "created_at": Tag.created_at,
-        }
-        sort_column = sort_columns.get(sort, Tag.name)
-        if order == "desc":
-            query = query.order_by(desc(sort_column))
-        else:
-            query = query.order_by(asc(sort_column))
-
-        # Apply pagination
-        offset = (page - 1) * limit
-        results = query.offset(offset).limit(limit).all()
-
-        return results, total
-
-    def create_tag(
-        self,
-        package_id: UUID,
-        name: str,
-        artifact_id: str,
-        created_by: str,
-    ) -> Tag:
-        """Create a new tag."""
-        return self.create(
-            package_id=package_id,
-            name=name,
-            artifact_id=artifact_id,
-            created_by=created_by,
-        )
-
-    def update_artifact(
-        self,
-        tag: Tag,
-        new_artifact_id: str,
-        changed_by: str,
-        record_history: bool = True,
-    ) -> Tag:
-        """
-        Update tag to point to a different artifact.
-        Optionally records change in tag history.
-        """
-        old_artifact_id = tag.artifact_id
-
-        if record_history and old_artifact_id != new_artifact_id:
-            history = TagHistory(
-                tag_id=tag.id,
-                old_artifact_id=old_artifact_id,
-                new_artifact_id=new_artifact_id,
-                changed_by=changed_by,
-            )
-            self.db.add(history)
-
-        tag.artifact_id = new_artifact_id
-        tag.created_by = changed_by
-        self.db.flush()
-        return tag
-
-    def get_history(self, tag_id: UUID) -> List[TagHistory]:
-        """Get tag change history."""
-        return (
-            self.db.query(TagHistory)
-            .filter(TagHistory.tag_id == tag_id)
-            .order_by(TagHistory.changed_at.desc())
-            .all()
-        )
-
-    def get_latest_in_package(self, package_id: UUID) -> Optional[Tag]:
-        """Get the most recently created/updated tag in a package."""
-        return (
-            self.db.query(Tag)
-            .filter(Tag.package_id == package_id)
-            .order_by(Tag.created_at.desc())
-            .first()
-        )
-
-    def get_by_artifact(self, artifact_id: str) -> List[Tag]:
-        """Get all tags pointing to an artifact."""
-        return (
-            self.db.query(Tag)
-            .filter(Tag.artifact_id == artifact_id)
-            .all()
-        )
-
-    def count_by_artifact(self, artifact_id: str) -> int:
-        """Count tags pointing to an artifact."""
-        return (
-            self.db.query(func.count(Tag.id))
-            .filter(Tag.artifact_id == artifact_id)
-            .scalar() or 0
-        )

backend/app/schemas.py

@@ -114,14 +114,6 @@ class PackageUpdate(BaseModel):
     platform: Optional[str] = None
 
 
-class TagSummary(BaseModel):
-    """Lightweight tag info for embedding in package responses"""
-
-    name: str
-    artifact_id: str
-    created_at: datetime
-
-
 class PackageDetailResponse(BaseModel):
     """Package with aggregated metadata"""
 
@@ -134,13 +126,9 @@ class PackageDetailResponse(BaseModel):
     created_at: datetime
     updated_at: datetime
     # Aggregated fields
-    tag_count: int = 0
     artifact_count: int = 0
     total_size: int = 0
-    latest_tag: Optional[str] = None
     latest_upload_at: Optional[datetime] = None
-    # Recent tags (limit 5)
-    recent_tags: List[TagSummary] = []
 
     class Config:
         from_attributes = True
@@ -165,79 +153,6 @@ class ArtifactResponse(BaseModel):
         from_attributes = True
 
 
-# Tag schemas
-class TagCreate(BaseModel):
-    name: str
-    artifact_id: str
-
-
-class TagResponse(BaseModel):
-    id: UUID
-    package_id: UUID
-    name: str
-    artifact_id: str
-    created_at: datetime
-    created_by: str
-    version: Optional[str] = None  # Version of the artifact this tag points to
-
-    class Config:
-        from_attributes = True
-
-
-class TagDetailResponse(BaseModel):
-    """Tag with embedded artifact metadata"""
-
-    id: UUID
-    package_id: UUID
-    name: str
-    artifact_id: str
-    created_at: datetime
-    created_by: str
-    version: Optional[str] = None  # Version of the artifact this tag points to
-    # Artifact metadata
-    artifact_size: int
-    artifact_content_type: Optional[str]
-    artifact_original_name: Optional[str]
-    artifact_created_at: datetime
-    artifact_format_metadata: Optional[Dict[str, Any]] = None
-
-    class Config:
-        from_attributes = True
-
-
-class TagHistoryResponse(BaseModel):
-    """History entry for tag changes"""
-
-    id: UUID
-    tag_id: UUID
-    old_artifact_id: Optional[str]
-    new_artifact_id: str
-    changed_at: datetime
-    changed_by: str
-
-    class Config:
-        from_attributes = True
-
-
-class TagHistoryDetailResponse(BaseModel):
-    """Tag history with artifact metadata for each version"""
-
-    id: UUID
-    tag_id: UUID
-    tag_name: str
-    old_artifact_id: Optional[str]
-    new_artifact_id: str
-    changed_at: datetime
-    changed_by: str
-    # Artifact metadata for new artifact
-    artifact_size: int
-    artifact_original_name: Optional[str]
-    artifact_content_type: Optional[str]
-
-    class Config:
-        from_attributes = True
-
-
 # Audit log schemas
 class AuditLogResponse(BaseModel):
     """Audit log entry response"""
@@ -264,7 +179,7 @@ class UploadHistoryResponse(BaseModel):
     package_name: str
     project_name: str
     original_name: Optional[str]
-    tag_name: Optional[str]
+    version: Optional[str]
     uploaded_at: datetime
     uploaded_by: str
     source_ip: Optional[str]
@@ -306,18 +221,8 @@ class ArtifactProvenanceResponse(BaseModel):
         from_attributes = True
 
 
-class ArtifactTagInfo(BaseModel):
-    """Tag info for embedding in artifact responses"""
-
-    id: UUID
-    name: str
-    package_id: UUID
-    package_name: str
-    project_name: str
-
-
 class ArtifactDetailResponse(BaseModel):
-    """Artifact with list of tags/packages referencing it"""
+    """Artifact with metadata"""
 
     id: str
     sha256: str  # Explicit SHA256 field (same as id)
@@ -331,14 +236,13 @@ class ArtifactDetailResponse(BaseModel):
     created_by: str
     ref_count: int
     format_metadata: Optional[Dict[str, Any]] = None
-    tags: List[ArtifactTagInfo] = []
 
     class Config:
         from_attributes = True
 
 
 class PackageArtifactResponse(BaseModel):
-    """Artifact with tags for package artifact listing"""
+    """Artifact for package artifact listing"""
 
     id: str
     sha256: str  # Explicit SHA256 field (same as id)
@@ -351,7 +255,6 @@ class PackageArtifactResponse(BaseModel):
     created_at: datetime
     created_by: str
     format_metadata: Optional[Dict[str, Any]] = None
-    tags: List[str] = []  # Tag names pointing to this artifact
 
     class Config:
         from_attributes = True
@@ -369,28 +272,9 @@ class GlobalArtifactResponse(BaseModel):
     created_by: str
     format_metadata: Optional[Dict[str, Any]] = None
     ref_count: int = 0
-    # Context from tags/packages
+    # Context from versions/packages
     projects: List[str] = []  # List of project names containing this artifact
     packages: List[str] = []  # List of "project/package" paths
-    tags: List[str] = []  # List of "project/package:tag" references
-
-    class Config:
-        from_attributes = True
-
-
-class GlobalTagResponse(BaseModel):
-    """Tag with project/package context for global listing"""
-
-    id: UUID
-    name: str
-    artifact_id: str
-    created_at: datetime
-    created_by: str
-    project_name: str
-    package_name: str
-    artifact_size: Optional[int] = None
-    artifact_content_type: Optional[str] = None
-    version: Optional[str] = None  # Version of the artifact this tag points to
 
     class Config:
         from_attributes = True
@@ -403,7 +287,6 @@ class UploadResponse(BaseModel):
     size: int
     project: str
     package: str
-    tag: Optional[str]
     version: Optional[str] = None  # Version assigned to this artifact
     version_source: Optional[str] = None  # How version was determined: 'explicit', 'filename', 'metadata'
     checksum_md5: Optional[str] = None
@@ -430,7 +313,6 @@ class ResumableUploadInitRequest(BaseModel):
     filename: str
     content_type: Optional[str] = None
     size: int
-    tag: Optional[str] = None
     version: Optional[str] = None  # Explicit version (auto-detected if not provided)
 
     @field_validator("expected_hash")
@@ -465,7 +347,7 @@ class ResumableUploadPartResponse(BaseModel):
 class ResumableUploadCompleteRequest(BaseModel):
     """Request to complete a resumable upload"""
 
-    tag: Optional[str] = None
+    pass
 
 
 class ResumableUploadCompleteResponse(BaseModel):
@@ -475,7 +357,6 @@ class ResumableUploadCompleteResponse(BaseModel):
     size: int
     project: str
     package: str
-    tag: Optional[str]
 
 
 class ResumableUploadStatusResponse(BaseModel):
@@ -528,7 +409,6 @@ class PackageVersionResponse(BaseModel):
     size: Optional[int] = None
     content_type: Optional[str] = None
     original_name: Optional[str] = None
-    tags: List[str] = []  # Tag names pointing to this artifact
 
     class Config:
         from_attributes = True
@@ -570,11 +450,10 @@ class SearchResultPackage(BaseModel):
 
 
 class SearchResultArtifact(BaseModel):
-    """Artifact/tag result for global search"""
+    """Artifact result for global search"""
 
-    tag_id: UUID
-    tag_name: str
     artifact_id: str
+    version: Optional[str]
     package_id: UUID
     package_name: str
     project_name: str
@@ -687,7 +566,6 @@ class ProjectStatsResponse(BaseModel):
     project_id: str
     project_name: str
     package_count: int
-    tag_count: int
     artifact_count: int
     total_size_bytes: int
     upload_count: int
@@ -702,7 +580,6 @@ class PackageStatsResponse(BaseModel):
     package_id: str
     package_name: str
     project_name: str
-    tag_count: int
     artifact_count: int
     total_size_bytes: int
     upload_count: int
@@ -719,7 +596,6 @@ class ArtifactStatsResponse(BaseModel):
     size: int
     ref_count: int
     storage_savings: int  # (ref_count - 1) * size
-    tags: List[Dict[str, Any]]  # Tags referencing this artifact
     projects: List[str]  # Projects using this artifact
     packages: List[str]  # Packages using this artifact
     first_uploaded: Optional[datetime] = None
@@ -930,20 +806,7 @@ class DependencyCreate(BaseModel):
     """Schema for creating a dependency"""
     project: str
     package: str
-    version: Optional[str] = None
-    tag: Optional[str] = None
-
-    @field_validator('version', 'tag')
-    @classmethod
-    def validate_constraint(cls, v, info):
-        return v
-
-    def model_post_init(self, __context):
-        """Validate that exactly one of version or tag is set"""
-        if self.version is None and self.tag is None:
-            raise ValueError("Either 'version' or 'tag' must be specified")
-        if self.version is not None and self.tag is not None:
-            raise ValueError("Cannot specify both 'version' and 'tag'")
+    version: str
 
 
 class DependencyResponse(BaseModel):
@@ -952,8 +815,7 @@ class DependencyResponse(BaseModel):
     artifact_id: str
     project: str
     package: str
-    version: Optional[str] = None
-    tag: Optional[str] = None
+    version: str
     created_at: datetime
 
     class Config:
@@ -968,7 +830,6 @@ class DependencyResponse(BaseModel):
             project=dep.dependency_project,
             package=dep.dependency_package,
             version=dep.version_constraint,
-            tag=dep.tag_constraint,
             created_at=dep.created_at,
         )
 
@@ -985,7 +846,6 @@ class DependentInfo(BaseModel):
     project: str
     package: str
     version: Optional[str] = None
-    constraint_type: str  # 'version' or 'tag'
     constraint_value: str
 
 
@@ -1001,20 +861,7 @@ class EnsureFileDependency(BaseModel):
     """Dependency entry from orchard.ensure file"""
     project: str
     package: str
-    version: Optional[str] = None
-    tag: Optional[str] = None
-
-    @field_validator('version', 'tag')
-    @classmethod
-    def validate_constraint(cls, v, info):
-        return v
-
-    def model_post_init(self, __context):
-        """Validate that exactly one of version or tag is set"""
-        if self.version is None and self.tag is None:
-            raise ValueError("Either 'version' or 'tag' must be specified")
-        if self.version is not None and self.tag is not None:
-            raise ValueError("Cannot specify both 'version' and 'tag'")
+    version: str
 
 
 class EnsureFileContent(BaseModel):
@@ -1028,7 +875,6 @@ class ResolvedArtifact(BaseModel):
     project: str
     package: str
     version: Optional[str] = None
-    tag: Optional[str] = None
     size: int
     download_url: str
 
@@ -1054,7 +900,7 @@ class DependencyConflict(BaseModel):
     """Details about a dependency conflict"""
     project: str
     package: str
-    requirements: List[Dict[str, Any]]  # version/tag and required_by info
+    requirements: List[Dict[str, Any]]  # version and required_by info
 
 
 class DependencyConflictError(BaseModel):
@@ -1388,10 +1234,10 @@ class CacheRequest(BaseModel):
     url: str
     source_type: str
     package_name: Optional[str] = None  # Auto-derived from URL if not provided
-    tag: Optional[str] = None  # Auto-derived from URL if not provided
+    version: Optional[str] = None  # Auto-derived from URL if not provided
     user_project: Optional[str] = None  # Cross-reference to user project
     user_package: Optional[str] = None
-    user_tag: Optional[str] = None
+    user_version: Optional[str] = None
     expected_hash: Optional[str] = None  # Verify downloaded content
 
     @field_validator('url')
@@ -1438,8 +1284,8 @@ class CacheResponse(BaseModel):
     source_name: Optional[str]
     system_project: str
     system_package: str
-    system_tag: Optional[str]
-    user_reference: Optional[str] = None  # e.g., "my-app/npm-deps:lodash-4.17.21"
+    system_version: Optional[str]
+    user_reference: Optional[str] = None  # e.g., "my-app/npm-deps/+/4.17.21"
 
 
 class CacheResolveRequest(BaseModel):
@@ -1453,7 +1299,7 @@ class CacheResolveRequest(BaseModel):
     version: str
     user_project: Optional[str] = None
     user_package: Optional[str] = None
-    user_tag: Optional[str] = None
+    user_version: Optional[str] = None
 
     @field_validator('source_type')
     @classmethod

backend/app/seed.py

@@ -5,7 +5,7 @@ import hashlib
 import logging
 from sqlalchemy.orm import Session
 
-from .models import Project, Package, Artifact, Tag, Upload, PackageVersion, ArtifactDependency, Team, TeamMembership, User
+from .models import Project, Package, Artifact, Upload, PackageVersion, ArtifactDependency, Team, TeamMembership, User
 from .storage import get_storage
 from .auth import hash_password
 
@@ -125,14 +125,14 @@ TEST_ARTIFACTS = [
 ]
 
 # Dependencies to create (source artifact -> dependency)
-# Format: (source_project, source_package, source_version, dep_project, dep_package, version_constraint, tag_constraint)
+# Format: (source_project, source_package, source_version, dep_project, dep_package, version_constraint)
 TEST_DEPENDENCIES = [
     # ui-components v1.1.0 depends on design-tokens v1.0.0
-    ("frontend-libs", "ui-components", "1.1.0", "frontend-libs", "design-tokens", "1.0.0", None),
+    ("frontend-libs", "ui-components", "1.1.0", "frontend-libs", "design-tokens", "1.0.0"),
     # auth-lib v1.0.0 depends on common-utils v2.0.0
-    ("backend-services", "auth-lib", "1.0.0", "backend-services", "common-utils", "2.0.0", None),
-    # auth-lib v1.0.0 also depends on design-tokens (stable tag)
-    ("backend-services", "auth-lib", "1.0.0", "frontend-libs", "design-tokens", None, "latest"),
+    ("backend-services", "auth-lib", "1.0.0", "backend-services", "common-utils", "2.0.0"),
+    # auth-lib v1.0.0 also depends on design-tokens v1.0.0
+    ("backend-services", "auth-lib", "1.0.0", "frontend-libs", "design-tokens", "1.0.0"),
 ]
 
 
@@ -252,9 +252,8 @@ def seed_database(db: Session) -> None:
 
     logger.info(f"Created {len(project_map)} projects and {len(package_map)} packages (assigned to {demo_team.slug})")
 
-    # Create artifacts, tags, and versions
+    # Create artifacts and versions
     artifact_count = 0
-    tag_count = 0
     version_count = 0
 
     for artifact_data in TEST_ARTIFACTS:
@@ -316,23 +315,12 @@ def seed_database(db: Session) -> None:
             db.add(version)
             version_count += 1
 
-        # Create tags
-        for tag_name in artifact_data["tags"]:
-            tag = Tag(
-                package_id=package.id,
-                name=tag_name,
-                artifact_id=sha256_hash,
-                created_by=team_owner_username,
-            )
-            db.add(tag)
-            tag_count += 1
-
     db.flush()
 
     # Create dependencies
     dependency_count = 0
     for dep_data in TEST_DEPENDENCIES:
-        src_project, src_package, src_version, dep_project, dep_package, version_constraint, tag_constraint = dep_data
+        src_project, src_package, src_version, dep_project, dep_package, version_constraint = dep_data
 
         # Find the source artifact by looking up its version
         src_pkg = package_map.get((src_project, src_package))
@@ -356,11 +344,10 @@ def seed_database(db: Session) -> None:
             dependency_project=dep_project,
             dependency_package=dep_package,
             version_constraint=version_constraint,
-            tag_constraint=tag_constraint,
         )
         db.add(dependency)
         dependency_count += 1
 
     db.commit()
-    logger.info(f"Created {artifact_count} artifacts, {tag_count} tags, {version_count} versions, and {dependency_count} dependencies")
+    logger.info(f"Created {artifact_count} artifacts, {version_count} versions, and {dependency_count} dependencies")
     logger.info("Database seeding complete")

backend/app/services/artifact_cleanup.py

@@ -6,9 +6,8 @@ from typing import List, Optional, Tuple
 from sqlalchemy.orm import Session
 import logging
 
-from ..models import Artifact, Tag
+from ..models import Artifact, PackageVersion
 from ..repositories.artifact import ArtifactRepository
-from ..repositories.tag import TagRepository
 from ..storage import S3Storage
 
 logger = logging.getLogger(__name__)
@@ -21,8 +20,8 @@ class ArtifactCleanupService:
     Reference counting rules:
     - ref_count starts at 1 when artifact is first uploaded
     - ref_count increments when the same artifact is uploaded again (deduplication)
-    - ref_count decrements when a tag is deleted or updated to point elsewhere
-    - ref_count decrements when a package is deleted (for each tag pointing to artifact)
+    - ref_count decrements when a version is deleted or updated to point elsewhere
+    - ref_count decrements when a package is deleted (for each version pointing to artifact)
     - When ref_count reaches 0, artifact is a candidate for deletion from S3
     """
 
@@ -30,12 +29,11 @@ class ArtifactCleanupService:
         self.db = db
         self.storage = storage
         self.artifact_repo = ArtifactRepository(db)
-        self.tag_repo = TagRepository(db)
 
-    def on_tag_deleted(self, artifact_id: str) -> Artifact:
+    def on_version_deleted(self, artifact_id: str) -> Artifact:
         """
-        Called when a tag is deleted.
-        Decrements ref_count for the artifact the tag was pointing to.
+        Called when a version is deleted.
+        Decrements ref_count for the artifact the version was pointing to.
         """
         artifact = self.artifact_repo.get_by_sha256(artifact_id)
         if artifact:
@@ -45,11 +43,11 @@ class ArtifactCleanupService:
             )
         return artifact
 
-    def on_tag_updated(
+    def on_version_updated(
         self, old_artifact_id: str, new_artifact_id: str
     ) -> Tuple[Optional[Artifact], Optional[Artifact]]:
         """
-        Called when a tag is updated to point to a different artifact.
+        Called when a version is updated to point to a different artifact.
         Decrements ref_count for old artifact, increments for new (if different).
 
         Returns (old_artifact, new_artifact) tuple.
@@ -79,21 +77,21 @@ class ArtifactCleanupService:
     def on_package_deleted(self, package_id) -> List[str]:
         """
         Called when a package is deleted.
-        Decrements ref_count for all artifacts that had tags in the package.
+        Decrements ref_count for all artifacts that had versions in the package.
 
         Returns list of artifact IDs that were affected.
         """
-        # Get all tags in the package before deletion
-        tags = self.db.query(Tag).filter(Tag.package_id == package_id).all()
+        # Get all versions in the package before deletion
+        versions = self.db.query(PackageVersion).filter(PackageVersion.package_id == package_id).all()
 
         affected_artifacts = []
-        for tag in tags:
-            artifact = self.artifact_repo.get_by_sha256(tag.artifact_id)
+        for version in versions:
+            artifact = self.artifact_repo.get_by_sha256(version.artifact_id)
             if artifact:
                 self.artifact_repo.decrement_ref_count(artifact)
-                affected_artifacts.append(tag.artifact_id)
+                affected_artifacts.append(version.artifact_id)
                 logger.info(
-                    f"Decremented ref_count for artifact {tag.artifact_id} (package delete)"
+                    f"Decremented ref_count for artifact {version.artifact_id} (package delete)"
                 )
 
         return affected_artifacts
@@ -152,7 +150,7 @@ class ArtifactCleanupService:
 
     def verify_ref_counts(self, fix: bool = False) -> List[dict]:
         """
-        Verify that ref_counts match actual tag references.
+        Verify that ref_counts match actual version references.
 
         Args:
             fix: If True, fix any mismatched ref_counts
@@ -162,28 +160,28 @@ class ArtifactCleanupService:
         """
         from sqlalchemy import func
 
-        # Get actual tag counts per artifact
-        tag_counts = (
-            self.db.query(Tag.artifact_id, func.count(Tag.id).label("tag_count"))
-            .group_by(Tag.artifact_id)
+        # Get actual version counts per artifact
+        version_counts = (
+            self.db.query(PackageVersion.artifact_id, func.count(PackageVersion.id).label("version_count"))
+            .group_by(PackageVersion.artifact_id)
             .all()
         )
-        tag_count_map = {artifact_id: count for artifact_id, count in tag_counts}
+        version_count_map = {artifact_id: count for artifact_id, count in version_counts}
 
         # Check all artifacts
         artifacts = self.db.query(Artifact).all()
         mismatches = []
 
         for artifact in artifacts:
-            actual_count = tag_count_map.get(artifact.id, 0)
+            actual_count = version_count_map.get(artifact.id, 0)
             # ref_count should be at least 1 (initial upload) + additional uploads
-            # But tags are the primary reference, so we check against tag count
+            # But versions are the primary reference, so we check against version count
 
             if artifact.ref_count < actual_count:
                 mismatch = {
                     "artifact_id": artifact.id,
                     "stored_ref_count": artifact.ref_count,
-                    "actual_tag_count": actual_count,
+                    "actual_version_count": actual_count,
                 }
                 mismatches.append(mismatch)
 

backend/tests/integration/test_tags_api.py

@@ -1,403 +0,0 @@
-"""
-Integration tests for tag API endpoints.
-
-Tests cover:
-- Tag CRUD operations
-- Tag listing with pagination and search
-- Tag history tracking
-- ref_count behavior with tag operations
-"""
-
-import pytest
-from tests.factories import compute_sha256, upload_test_file
-
-
-class TestTagCRUD:
-    """Tests for tag create, read, delete operations."""
-
-    @pytest.mark.integration
-    def test_create_tag_via_upload(self, integration_client, test_package):
-        """Test creating a tag via upload endpoint."""
-        project_name, package_name = test_package
-
-        result = upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"tag create test",
-            tag="v1.0.0",
-        )
-
-        assert result["tag"] == "v1.0.0"
-        assert result["artifact_id"]
-
-    @pytest.mark.integration
-    def test_create_tag_via_post(
-        self, integration_client, test_package, unique_test_id
-    ):
-        """Test creating a tag via POST /tags endpoint."""
-        project_name, package_name = test_package
-
-        # First upload an artifact
-        result = upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"artifact for tag",
-        )
-        artifact_id = result["artifact_id"]
-
-        # Create tag via POST
-        tag_name = f"post-tag-{unique_test_id}"
-        response = integration_client.post(
-            f"/api/v1/project/{project_name}/{package_name}/tags",
-            json={"name": tag_name, "artifact_id": artifact_id},
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        assert data["name"] == tag_name
-        assert data["artifact_id"] == artifact_id
-
-    @pytest.mark.integration
-    def test_get_tag(self, integration_client, test_package):
-        """Test getting a tag by name."""
-        project_name, package_name = test_package
-
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"get tag test",
-            tag="get-tag",
-        )
-
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags/get-tag"
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        assert data["name"] == "get-tag"
-        assert "artifact_id" in data
-        assert "artifact_size" in data
-        assert "artifact_content_type" in data
-
-    @pytest.mark.integration
-    def test_list_tags(self, integration_client, test_package):
-        """Test listing tags for a package."""
-        project_name, package_name = test_package
-
-        # Create some tags
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"list tags test",
-            tag="list-v1",
-        )
-
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags"
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        assert "items" in data
-        assert "pagination" in data
-
-        tag_names = [t["name"] for t in data["items"]]
-        assert "list-v1" in tag_names
-
-    @pytest.mark.integration
-    def test_delete_tag(self, integration_client, test_package):
-        """Test deleting a tag."""
-        project_name, package_name = test_package
-
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"delete tag test",
-            tag="to-delete",
-        )
-
-        # Delete tag
-        response = integration_client.delete(
-            f"/api/v1/project/{project_name}/{package_name}/tags/to-delete"
-        )
-        assert response.status_code == 204
-
-        # Verify deleted
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags/to-delete"
-        )
-        assert response.status_code == 404
-
-
-class TestTagListingFilters:
-    """Tests for tag listing with filters and search."""
-
-    @pytest.mark.integration
-    def test_tags_pagination(self, integration_client, test_package):
-        """Test tag listing respects pagination."""
-        project_name, package_name = test_package
-
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags?limit=5"
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        assert len(data["items"]) <= 5
-        assert data["pagination"]["limit"] == 5
-
-    @pytest.mark.integration
-    def test_tags_search(self, integration_client, test_package, unique_test_id):
-        """Test tag search by name."""
-        project_name, package_name = test_package
-
-        tag_name = f"searchable-{unique_test_id}"
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"search test",
-            tag=tag_name,
-        )
-
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags?search=searchable"
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        tag_names = [t["name"] for t in data["items"]]
-        assert tag_name in tag_names
-
-
-class TestTagHistory:
-    """Tests for tag history tracking."""
-
-    @pytest.mark.integration
-    def test_tag_history_on_create(self, integration_client, test_package):
-        """Test tag history is created when tag is created."""
-        project_name, package_name = test_package
-
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"history create test",
-            tag="history-create",
-        )
-
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags/history-create/history"
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        assert len(data) >= 1
-
-    @pytest.mark.integration
-    def test_tag_history_on_update(
-        self, integration_client, test_package, unique_test_id
-    ):
-        """Test tag history is created when tag is updated."""
-        project_name, package_name = test_package
-
-        tag_name = f"history-update-{unique_test_id}"
-
-        # Create tag with first artifact
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"first content",
-            tag=tag_name,
-        )
-
-        # Update tag with second artifact
-        upload_test_file(
-            integration_client,
-            project_name,
-            package_name,
-            b"second content",
-            tag=tag_name,
-        )
-
-        response = integration_client.get(
-            f"/api/v1/project/{project_name}/{package_name}/tags/{tag_name}/history"
-        )
-        assert response.status_code == 200
-
-        data = response.json()
-        # Should have at least 2 history entries (create + update)
-        assert len(data) >= 2
-
-
-class TestTagRefCount:
-    """Tests for ref_count behavior with tag operations."""
-
-    @pytest.mark.integration
-    def test_ref_count_decrements_on_tag_delete(self, integration_client, test_package):
-        """Test ref_count decrements when a tag is deleted."""
-        project_name, package_name = test_package
-        content = b"ref count delete test"
-        expected_hash = compute_sha256(content)
-
-        # Upload with two tags
-        upload_test_file(
-            integration_client, project_name, package_name, content, tag="rc-v1"
-        )
-        upload_test_file(
-            integration_client, project_name, package_name, content, tag="rc-v2"
-        )
-
-        # Verify ref_count is 2
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 2
-
-        # Delete one tag
-        delete_response = integration_client.delete(
-            f"/api/v1/project/{project_name}/{package_name}/tags/rc-v1"
-        )
-        assert delete_response.status_code == 204
-
-        # Verify ref_count is now 1
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 1
-
-    @pytest.mark.integration
-    def test_ref_count_zero_after_all_tags_deleted(
-        self, integration_client, test_package
-    ):
-        """Test ref_count goes to 0 when all tags are deleted."""
-        project_name, package_name = test_package
-        content = b"orphan test content"
-        expected_hash = compute_sha256(content)
-
-        # Upload with one tag
-        upload_test_file(
-            integration_client, project_name, package_name, content, tag="only-tag"
-        )
-
-        # Delete the tag
-        integration_client.delete(
-            f"/api/v1/project/{project_name}/{package_name}/tags/only-tag"
-        )
-
-        # Verify ref_count is 0
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 0
-
-    @pytest.mark.integration
-    def test_ref_count_adjusts_on_tag_update(
-        self, integration_client, test_package, unique_test_id
-    ):
-        """Test ref_count adjusts when a tag is updated to point to different artifact."""
-        project_name, package_name = test_package
-
-        # Upload two different artifacts
-        content1 = f"artifact one {unique_test_id}".encode()
-        content2 = f"artifact two {unique_test_id}".encode()
-        hash1 = compute_sha256(content1)
-        hash2 = compute_sha256(content2)
-
-        # Upload first artifact with tag "latest"
-        upload_test_file(
-            integration_client, project_name, package_name, content1, tag="latest"
-        )
-
-        # Verify first artifact has ref_count 1
-        response = integration_client.get(f"/api/v1/artifact/{hash1}")
-        assert response.json()["ref_count"] == 1
-
-        # Upload second artifact with different tag
-        upload_test_file(
-            integration_client, project_name, package_name, content2, tag="stable"
-        )
-
-        # Now update "latest" tag to point to second artifact
-        upload_test_file(
-            integration_client, project_name, package_name, content2, tag="latest"
-        )
-
-        # Verify first artifact ref_count decreased to 0
-        response = integration_client.get(f"/api/v1/artifact/{hash1}")
-        assert response.json()["ref_count"] == 0
-
-        # Verify second artifact ref_count increased to 2
-        response = integration_client.get(f"/api/v1/artifact/{hash2}")
-        assert response.json()["ref_count"] == 2
-
-    @pytest.mark.integration
-    def test_ref_count_unchanged_when_tag_same_artifact(
-        self, integration_client, test_package, unique_test_id
-    ):
-        """Test ref_count doesn't change when tag is 'updated' to same artifact."""
-        project_name, package_name = test_package
-
-        content = f"same artifact {unique_test_id}".encode()
-        expected_hash = compute_sha256(content)
-
-        # Upload with tag
-        upload_test_file(
-            integration_client, project_name, package_name, content, tag="same-v1"
-        )
-
-        # Verify ref_count is 1
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 1
-
-        # Upload same content with same tag (no-op)
-        upload_test_file(
-            integration_client, project_name, package_name, content, tag="same-v1"
-        )
-
-        # Verify ref_count is still 1
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 1
-
-    @pytest.mark.integration
-    def test_tag_via_post_endpoint_increments_ref_count(
-        self, integration_client, test_package, unique_test_id
-    ):
-        """Test creating tag via POST /tags endpoint increments ref_count."""
-        project_name, package_name = test_package
-
-        content = f"tag endpoint test {unique_test_id}".encode()
-        expected_hash = compute_sha256(content)
-
-        # Upload artifact without tag
-        result = upload_test_file(
-            integration_client, project_name, package_name, content, filename="test.bin"
-        )
-        artifact_id = result["artifact_id"]
-
-        # Verify ref_count is 0 (no tags yet)
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 0
-
-        # Create tag via POST endpoint
-        tag_response = integration_client.post(
-            f"/api/v1/project/{project_name}/{package_name}/tags",
-            json={"name": "post-v1", "artifact_id": artifact_id},
-        )
-        assert tag_response.status_code == 200
-
-        # Verify ref_count is now 1
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 1
-
-        # Create another tag via POST endpoint
-        tag_response = integration_client.post(
-            f"/api/v1/project/{project_name}/{package_name}/tags",
-            json={"name": "post-latest", "artifact_id": artifact_id},
-        )
-        assert tag_response.status_code == 200
-
-        # Verify ref_count is now 2
-        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
-        assert response.json()["ref_count"] == 2

frontend/src/api.ts

@@ -1,14 +1,11 @@
 import {
   Project,
   Package,
-  Tag,
-  TagDetail,
   ArtifactDetail,
   PackageArtifact,
   UploadResponse,
   PaginatedResponse,
   ListParams,
-  TagListParams,
   PackageListParams,
   ArtifactListParams,
   ProjectListParams,
@@ -240,32 +237,6 @@ export async function createPackage(projectName: string, data: { name: string; d
   return handleResponse<Package>(response);
 }
 
-// Tag API
-export async function listTags(projectName: string, packageName: string, params: TagListParams = {}): Promise<PaginatedResponse<TagDetail>> {
-  const query = buildQueryString(params as Record<string, unknown>);
-  const response = await fetch(`${API_BASE}/project/${projectName}/${packageName}/tags${query}`);
-  return handleResponse<PaginatedResponse<TagDetail>>(response);
-}
-
-export async function listTagsSimple(projectName: string, packageName: string, params: TagListParams = {}): Promise<TagDetail[]> {
-  const data = await listTags(projectName, packageName, params);
-  return data.items;
-}
-
-export async function getTag(projectName: string, packageName: string, tagName: string): Promise<TagDetail> {
-  const response = await fetch(`${API_BASE}/project/${projectName}/${packageName}/tags/${tagName}`);
-  return handleResponse<TagDetail>(response);
-}
-
-export async function createTag(projectName: string, packageName: string, data: { name: string; artifact_id: string }): Promise<Tag> {
-  const response = await fetch(`${API_BASE}/project/${projectName}/${packageName}/tags`, {
-    method: 'POST',
-    headers: { 'Content-Type': 'application/json' },
-    body: JSON.stringify(data),
-  });
-  return handleResponse<Tag>(response);
-}
-
 // Artifact API
 export async function getArtifact(artifactId: string): Promise<ArtifactDetail> {
   const response = await fetch(`${API_BASE}/artifact/${artifactId}`);
@@ -287,14 +258,10 @@ export async function uploadArtifact(
   projectName: string,
   packageName: string,
   file: File,
-  tag?: string,
   version?: string
 ): Promise<UploadResponse> {
   const formData = new FormData();
   formData.append('file', file);
-  if (tag) {
-    formData.append('tag', tag);
-  }
   if (version) {
     formData.append('version', version);
   }

frontend/src/components/DependencyGraph.tsx

@@ -170,7 +170,7 @@ function DependencyGraph({ projectName, packageName, tagName, onClose }: Depende
           label: `${artifact.project}/${artifact.package}`,
           project: artifact.project,
           package: artifact.package,
-          version: artifact.version || artifact.tag,
+          version: artifact.version,
           size: artifact.size,
           isRoot,
           onNavigate,

frontend/src/components/DragDropUpload.test.tsx

@@ -524,7 +524,7 @@ describe('DragDropUpload', () => {
       }
       vi.stubGlobal('XMLHttpRequest', MockXHR);
       
-      render(<DragDropUpload {...defaultProps} tag="v1.0.0" />);
+      render(<DragDropUpload {...defaultProps} />);
       
       const input = document.querySelector('input[type="file"]') as HTMLInputElement;
       const file = createMockFile('test.txt', 100, 'text/plain');

frontend/src/components/DragDropUpload.tsx

@@ -13,7 +13,6 @@ interface StoredUploadState {
   completedParts: number[];
   project: string;
   package: string;
-  tag?: string;
   createdAt: number;
 }
 
@@ -87,7 +86,6 @@ export interface DragDropUploadProps {
   maxFileSize?: number; // in bytes
   maxConcurrentUploads?: number;
   maxRetries?: number;
-  tag?: string;
   className?: string;
   disabled?: boolean;
   disabledReason?: string;
@@ -230,7 +228,6 @@ export function DragDropUpload({
   maxFileSize,
   maxConcurrentUploads = 3,
   maxRetries = 3,
-  tag,
   className = '',
   disabled = false,
   disabledReason,
@@ -368,7 +365,6 @@ export function DragDropUpload({
             expected_hash: fileHash,
             filename: item.file.name,
             size: item.file.size,
-            tag: tag || undefined,
           }),
         }
       );
@@ -392,7 +388,6 @@ export function DragDropUpload({
         completedParts: [],
         project: projectName,
         package: packageName,
-        tag: tag || undefined,
         createdAt: Date.now(),
       });
 
@@ -438,7 +433,6 @@ export function DragDropUpload({
         completedParts,
         project: projectName,
         package: packageName,
-        tag: tag || undefined,
         createdAt: Date.now(),
       });
 
@@ -459,7 +453,7 @@ export function DragDropUpload({
       {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ tag: tag || undefined }),
+        body: JSON.stringify({}),
       }
     );
 
@@ -475,7 +469,7 @@ export function DragDropUpload({
       size: completeData.size,
       deduplicated: false,
     };
-  }, [projectName, packageName, tag, isOnline]);
+  }, [projectName, packageName, isOnline]);
 
   const uploadFileSimple = useCallback((item: UploadItem): Promise<UploadResult> => {
     return new Promise((resolve, reject) => {
@@ -484,9 +478,6 @@ export function DragDropUpload({
 
       const formData = new FormData();
       formData.append('file', item.file);
-      if (tag) {
-        formData.append('tag', tag);
-      }
 
       let lastLoaded = 0;
       let lastTime = Date.now();
@@ -555,7 +546,7 @@ export function DragDropUpload({
           : u
       ));
     });
-  }, [projectName, packageName, tag]);
+  }, [projectName, packageName]);
 
   const uploadFile = useCallback((item: UploadItem): Promise<UploadResult> => {
     if (item.file.size >= CHUNKED_UPLOAD_THRESHOLD) {

frontend/src/components/GlobalSearch.tsx

@@ -233,7 +233,7 @@ export function GlobalSearch() {
                     const flatIndex = results.projects.length + results.packages.length + index;
                     return (
                       <button
-                        key={artifact.tag_id}
+                        key={artifact.artifact_id}
                         className={`global-search__result ${selectedIndex === flatIndex ? 'selected' : ''}`}
                         onClick={() => navigateToResult({ type: 'artifact', item: artifact })}
                         onMouseEnter={() => setSelectedIndex(flatIndex)}
@@ -243,7 +243,7 @@ export function GlobalSearch() {
                           <line x1="7" y1="7" x2="7.01" y2="7" />
                         </svg>
                         <div className="global-search__result-content">
-                          <span className="global-search__result-name">{artifact.tag_name}</span>
+                          <span className="global-search__result-name">{artifact.version}</span>
                           <span className="global-search__result-path">
                             {artifact.project_name} / {artifact.package_name}
                           </span>

frontend/src/pages/PackagePage.tsx

@@ -1,7 +1,7 @@
 import { useState, useEffect, useCallback } from 'react';
 import { useParams, useSearchParams, useNavigate, useLocation, Link } from 'react-router-dom';
 import { PackageArtifact, Package, PaginatedResponse, AccessLevel, Dependency, DependentInfo } from '../types';
-import { listPackageArtifacts, getDownloadUrl, getPackage, getMyProjectAccess, createTag, getArtifactDependencies, getReverseDependencies, getEnsureFile, UnauthorizedError, ForbiddenError } from '../api';
+import { listPackageArtifacts, getDownloadUrl, getPackage, getMyProjectAccess, getArtifactDependencies, getReverseDependencies, getEnsureFile, UnauthorizedError, ForbiddenError } from '../api';
 import { Breadcrumb } from '../components/Breadcrumb';
 import { Badge } from '../components/Badge';
 import { SearchInput } from '../components/SearchInput';
@@ -61,16 +61,11 @@ function PackagePage() {
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
   const [accessDenied, setAccessDenied] = useState(false);
-  const [uploadTag, setUploadTag] = useState('');
   const [uploadSuccess, setUploadSuccess] = useState<string | null>(null);
   const [accessLevel, setAccessLevel] = useState<AccessLevel | null>(null);
-  const [createTagName, setCreateTagName] = useState('');
-  const [createTagArtifactId, setCreateTagArtifactId] = useState('');
-  const [createTagLoading, setCreateTagLoading] = useState(false);
 
   // UI state
   const [showUploadModal, setShowUploadModal] = useState(false);
-  const [showCreateTagModal, setShowCreateTagModal] = useState(false);
   const [openMenuId, setOpenMenuId] = useState<string | null>(null);
   const [menuPosition, setMenuPosition] = useState<{ top: number; left: number } | null>(null);
 
@@ -226,15 +221,15 @@ function PackagePage() {
     }
   }, [projectName, packageName, loading, fetchReverseDeps]);
 
-  // Fetch ensure file for a specific tag
-  const fetchEnsureFileForTag = useCallback(async (tagName: string) => {
+  // Fetch ensure file for a specific version or artifact
+  const fetchEnsureFileForRef = useCallback(async (ref: string) => {
     if (!projectName || !packageName) return;
 
-    setEnsureFileTagName(tagName);
+    setEnsureFileTagName(ref);
     setEnsureFileLoading(true);
     setEnsureFileError(null);
     try {
-      const content = await getEnsureFile(projectName, packageName, tagName);
+      const content = await getEnsureFile(projectName, packageName, ref);
       setEnsureFileContent(content);
       setShowEnsureFile(true);
     } catch (err) {
@@ -245,11 +240,13 @@ function PackagePage() {
     }
   }, [projectName, packageName]);
 
-  // Fetch ensure file for selected artifact (if it has tags)
+  // Fetch ensure file for selected artifact
   const fetchEnsureFile = useCallback(async () => {
-    if (!selectedArtifact || selectedArtifact.tags.length === 0) return;
-    fetchEnsureFileForTag(selectedArtifact.tags[0]);
-  }, [selectedArtifact, fetchEnsureFileForTag]);
+    if (!selectedArtifact) return;
+    const version = getArtifactVersion(selectedArtifact);
+    const ref = version || `artifact:${selectedArtifact.id}`;
+    fetchEnsureFileForRef(ref);
+  }, [selectedArtifact, fetchEnsureFileForRef]);
 
   // Keyboard navigation - go back with backspace
   useEffect(() => {
@@ -269,7 +266,6 @@ function PackagePage() {
       ? `Uploaded successfully! Artifact ID: ${results[0].artifact_id}`
       : `${count} files uploaded successfully!`;
     setUploadSuccess(message);
-    setUploadTag('');
     loadData();
     
     // Auto-dismiss success message after 5 seconds
@@ -280,30 +276,6 @@ function PackagePage() {
     setError(errorMsg);
   }, []);
 
-  const handleCreateTag = async (e: React.FormEvent) => {
-    e.preventDefault();
-    if (!createTagName.trim() || createTagArtifactId.length !== 64) return;
-
-    setCreateTagLoading(true);
-    setError(null);
-
-    try {
-      await createTag(projectName!, packageName!, {
-        name: createTagName.trim(),
-        artifact_id: createTagArtifactId,
-      });
-      setUploadSuccess(`Tag "${createTagName}" created successfully!`);
-      setCreateTagName('');
-      setCreateTagArtifactId('');
-      loadData();
-      setTimeout(() => setUploadSuccess(null), 5000);
-    } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to create tag');
-    } finally {
-      setCreateTagLoading(false);
-    }
-  };
-
   const handleSearchChange = (value: string) => {
     updateParams({ search: value, page: '1' });
   };
@@ -346,9 +318,10 @@ function PackagePage() {
     return (a.format_metadata?.version as string) || null;
   };
 
-  // Helper to get download ref - prefer first tag, fallback to artifact ID
+  // Helper to get download ref - prefer version, fallback to artifact ID
   const getDownloadRef = (a: PackageArtifact): string => {
-    return a.tags.length > 0 ? a.tags[0] : `artifact:${a.id}`;
+    const version = getArtifactVersion(a);
+    return version || `artifact:${a.id}`;
   };
 
   // System projects show Version first, regular projects show Tag first
@@ -365,7 +338,7 @@ function PackagePage() {
               onClick={() => handleArtifactSelect(a)}
               style={{ cursor: 'pointer' }}
             >
-              <span className="version-badge">{getArtifactVersion(a) || a.tags[0] || a.id.slice(0, 12)}</span>
+              <span className="version-badge">{getArtifactVersion(a) || a.id.slice(0, 12)}</span>
             </strong>
           ),
         },
@@ -425,30 +398,22 @@ function PackagePage() {
         },
       ]
     : [
-        // Regular project columns: Tag, Version, Filename, Size, Created
+        // Regular project columns: Version, Filename, Size, Created
         // Valid sort fields: created_at, size, original_name
         {
-          key: 'tags',
-          header: 'Tag',
-          // tags is not a sortable DB field
+          key: 'version',
+          header: 'Version',
+          // version is from format_metadata, not a sortable DB field
           render: (a: PackageArtifact) => (
             <strong
               className={`tag-name-link ${selectedArtifact?.id === a.id ? 'selected' : ''}`}
               onClick={() => handleArtifactSelect(a)}
               style={{ cursor: 'pointer' }}
             >
-              {a.tags.length > 0 ? a.tags[0] : '—'}
+              <span className="version-badge">{getArtifactVersion(a) || a.id.slice(0, 12)}</span>
             </strong>
           ),
         },
-        {
-          key: 'version',
-          header: 'Version',
-          // version is from format_metadata, not a sortable DB field
-          render: (a: PackageArtifact) => (
-            <span className="version-badge">{getArtifactVersion(a) || '—'}</span>
-          ),
-        },
         {
           key: 'original_name',
           header: 'Filename',
@@ -536,16 +501,9 @@ function PackagePage() {
           <button onClick={() => { navigator.clipboard.writeText(a.id); setOpenMenuId(null); setMenuPosition(null); }}>
             Copy Artifact ID
           </button>
-          {a.tags.length > 0 && (
-            <button onClick={() => { fetchEnsureFileForTag(a.tags[0]); setOpenMenuId(null); setMenuPosition(null); }}>
-              View Ensure File
-            </button>
-          )}
-          {canWrite && !isSystemProject && (
-            <button onClick={() => { setCreateTagArtifactId(a.id); setShowCreateTagModal(true); setOpenMenuId(null); setMenuPosition(null); }}>
-              Create/Update Tag
-            </button>
-          )}
+          <button onClick={() => { const version = getArtifactVersion(a); const ref = version || `artifact:${a.id}`; fetchEnsureFileForRef(ref); setOpenMenuId(null); setMenuPosition(null); }}>
+            View Ensure File
+          </button>
           <button onClick={() => { handleArtifactSelect(a); setShowDepsModal(true); setOpenMenuId(null); setMenuPosition(null); }}>
             View Dependencies
           </button>
@@ -623,13 +581,8 @@ function PackagePage() {
               </>
             )}
           </div>
-          {pkg && (pkg.tag_count !== undefined || pkg.artifact_count !== undefined) && (
+          {pkg && pkg.artifact_count !== undefined && (
             <div className="package-header-stats">
-              {!isSystemProject && pkg.tag_count !== undefined && (
-                <span className="stat-item">
-                  <strong>{pkg.tag_count}</strong> tags
-                </span>
-              )}
               {pkg.artifact_count !== undefined && (
                 <span className="stat-item">
                   <strong>{pkg.artifact_count}</strong> {isSystemProject ? 'versions' : 'artifacts'}
@@ -640,11 +593,6 @@ function PackagePage() {
                   <strong>{formatBytes(pkg.total_size)}</strong> total
                 </span>
               )}
-              {!isSystemProject && pkg.latest_tag && (
-                <span className="stat-item">
-                  Latest: <strong className="accent">{pkg.latest_tag}</strong>
-                </span>
-              )}
             </div>
           )}
         </div>
@@ -655,7 +603,7 @@ function PackagePage() {
 
 
       <div className="section-header">
-        <h2>{isSystemProject ? 'Versions' : 'Tags / Versions'}</h2>
+        <h2>{isSystemProject ? 'Versions' : 'Artifacts'}</h2>
       </div>
 
       <div className="list-controls">
@@ -754,9 +702,9 @@ function PackagePage() {
         <pre>
           <code>curl -O {window.location.origin}/api/v1/project/{projectName}/{packageName}/+/latest</code>
         </pre>
-        <p>Or with a specific tag:</p>
+        <p>Or with a specific version:</p>
         <pre>
-          <code>curl -O {window.location.origin}/api/v1/project/{projectName}/{packageName}/+/v1.0.0</code>
+          <code>curl -O {window.location.origin}/api/v1/project/{projectName}/{packageName}/+/1.0.0</code>
         </pre>
       </div>
 
@@ -765,7 +713,7 @@ function PackagePage() {
         <DependencyGraph
           projectName={projectName!}
           packageName={packageName!}
-          tagName={selectedArtifact.tags.length > 0 ? selectedArtifact.tags[0] : `artifact:${selectedArtifact.id}`}
+          tagName={getArtifactVersion(selectedArtifact) || `artifact:${selectedArtifact.id}`}
           onClose={() => setShowGraph(false)}
         />
       )}
@@ -788,24 +736,12 @@ function PackagePage() {
               </button>
             </div>
             <div className="modal-body">
-              <div className="form-group">
-                <label htmlFor="upload-tag">Tag (optional)</label>
-                <input
-                  id="upload-tag"
-                  type="text"
-                  value={uploadTag}
-                  onChange={(e) => setUploadTag(e.target.value)}
-                  placeholder="v1.0.0, latest, stable..."
-                />
-              </div>
               <DragDropUpload
                 projectName={projectName!}
                 packageName={packageName!}
-                tag={uploadTag || undefined}
                 onUploadComplete={(result) => {
                   handleUploadComplete(result);
                   setShowUploadModal(false);
-                  setUploadTag('');
                 }}
                 onUploadError={handleUploadError}
               />
@@ -814,74 +750,6 @@ function PackagePage() {
         </div>
       )}
 
-      {/* Create/Update Tag Modal */}
-      {showCreateTagModal && (
-        <div className="modal-overlay" onClick={() => setShowCreateTagModal(false)}>
-          <div className="create-tag-modal" onClick={(e) => e.stopPropagation()}>
-            <div className="modal-header">
-              <h3>Create / Update Tag</h3>
-              <button
-                className="modal-close"
-                onClick={() => { setShowCreateTagModal(false); setCreateTagName(''); setCreateTagArtifactId(''); }}
-                title="Close"
-              >
-                <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
-                  <line x1="18" y1="6" x2="6" y2="18"></line>
-                  <line x1="6" y1="6" x2="18" y2="18"></line>
-                </svg>
-              </button>
-            </div>
-            <div className="modal-body">
-              <p className="modal-description">Point a tag at an artifact by its ID</p>
-              <form onSubmit={(e) => { handleCreateTag(e); setShowCreateTagModal(false); }}>
-                <div className="form-group">
-                  <label htmlFor="modal-tag-name">Tag Name</label>
-                  <input
-                    id="modal-tag-name"
-                    type="text"
-                    value={createTagName}
-                    onChange={(e) => setCreateTagName(e.target.value)}
-                    placeholder="latest, stable, v1.0.0..."
-                    disabled={createTagLoading}
-                  />
-                </div>
-                <div className="form-group">
-                  <label htmlFor="modal-artifact-id">Artifact ID</label>
-                  <input
-                    id="modal-artifact-id"
-                    type="text"
-                    value={createTagArtifactId}
-                    onChange={(e) => setCreateTagArtifactId(e.target.value.toLowerCase().replace(/[^a-f0-9]/g, '').slice(0, 64))}
-                    placeholder="SHA256 hash (64 hex characters)"
-                    className="artifact-id-input"
-                    disabled={createTagLoading}
-                  />
-                  {createTagArtifactId.length > 0 && createTagArtifactId.length !== 64 && (
-                    <p className="validation-hint">{createTagArtifactId.length}/64 characters</p>
-                  )}
-                </div>
-                <div className="modal-actions">
-                  <button
-                    type="button"
-                    className="btn btn-secondary"
-                    onClick={() => { setShowCreateTagModal(false); setCreateTagName(''); setCreateTagArtifactId(''); }}
-                  >
-                    Cancel
-                  </button>
-                  <button
-                    type="submit"
-                    className="btn btn-primary"
-                    disabled={createTagLoading || !createTagName.trim() || createTagArtifactId.length !== 64}
-                  >
-                    {createTagLoading ? 'Creating...' : 'Create Tag'}
-                  </button>
-                </div>
-              </form>
-            </div>
-          </div>
-        </div>
-      )}
-
       {/* Ensure File Modal */}
       {showEnsureFile && (
         <div className="modal-overlay" onClick={() => setShowEnsureFile(false)}>
@@ -943,15 +811,13 @@ function PackagePage() {
             </div>
             <div className="modal-body">
               <div className="deps-modal-controls">
-                {selectedArtifact?.tags && selectedArtifact.tags.length > 0 && (
-                  <button
-                    className="btn btn-secondary btn-small"
-                    onClick={fetchEnsureFile}
-                    disabled={ensureFileLoading}
-                  >
-                    View Ensure File
-                  </button>
-                )}
+                <button
+                  className="btn btn-secondary btn-small"
+                  onClick={fetchEnsureFile}
+                  disabled={ensureFileLoading}
+                >
+                  View Ensure File
+                </button>
                 <button
                   className="btn btn-secondary btn-small"
                   onClick={() => { setShowDepsModal(false); setShowGraph(true); }}
@@ -981,7 +847,7 @@ function PackagePage() {
                           {dep.project}/{dep.package}
                         </Link>
                         <span className="dep-constraint">
-                          @ {dep.version || dep.tag}
+                          @ {dep.version}
                         </span>
                         <span className="dep-status dep-status--ok" title="Package exists">
                           &#10003;

frontend/src/pages/ProjectPage.tsx

@@ -349,9 +349,9 @@ function ProjectPage() {
               render: (pkg: Package) => <Badge variant="default">{pkg.format}</Badge>,
             }] : []),
             ...(!project?.is_system ? [{
-              key: 'tag_count',
-              header: 'Tags',
-              render: (pkg: Package) => pkg.tag_count ?? '—',
+              key: 'version_count',
+              header: 'Versions',
+              render: (pkg: Package) => pkg.version_count ?? '—',
             }] : []),
             {
               key: 'artifact_count',
@@ -365,10 +365,10 @@ function ProjectPage() {
                 pkg.total_size !== undefined && pkg.total_size > 0 ? formatBytes(pkg.total_size) : '—',
             },
             ...(!project?.is_system ? [{
-              key: 'latest_tag',
+              key: 'latest_version',
               header: 'Latest',
               render: (pkg: Package) =>
-                pkg.latest_tag ? <strong style={{ color: 'var(--accent-primary)' }}>{pkg.latest_tag}</strong> : '—',
+                pkg.latest_version ? <strong style={{ color: 'var(--accent-primary)' }}>{pkg.latest_version}</strong> : '—',
             }] : []),
             {
               key: 'created_at',

frontend/src/types.ts

@@ -19,12 +19,6 @@ export interface Project {
   team_name?: string | null;
 }
 
-export interface TagSummary {
-  name: string;
-  artifact_id: string;
-  created_at: string;
-}
-
 export interface Package {
   id: string;
   project_id: string;
@@ -35,12 +29,11 @@ export interface Package {
   created_at: string;
   updated_at: string;
   // Aggregated fields (from PackageDetailResponse)
-  tag_count?: number;
   artifact_count?: number;
+  version_count?: number;
   total_size?: number;
-  latest_tag?: string | null;
   latest_upload_at?: string | null;
-  recent_tags?: TagSummary[];
+  latest_version?: string | null;
 }
 
 export interface Artifact {
@@ -65,25 +58,6 @@ export interface PackageArtifact {
   created_at: string;
   created_by: string;
   format_metadata?: Record<string, unknown> | null;
-  tags: string[];
-}
-
-export interface Tag {
-  id: string;
-  package_id: string;
-  name: string;
-  artifact_id: string;
-  created_at: string;
-  created_by: string;
-}
-
-export interface TagDetail extends Tag {
-  artifact_size: number;
-  artifact_content_type: string | null;
-  artifact_original_name: string | null;
-  artifact_created_at: string;
-  artifact_format_metadata: Record<string, unknown> | null;
-  version: string | null;
 }
 
 export interface PackageVersion {
@@ -98,20 +72,9 @@ export interface PackageVersion {
   size?: number;
   content_type?: string | null;
   original_name?: string | null;
-  tags?: string[];
 }
 
-export interface ArtifactTagInfo {
-  id: string;
-  name: string;
-  package_id: string;
-  package_name: string;
-  project_name: string;
-}
-
-export interface ArtifactDetail extends Artifact {
-  tags: ArtifactTagInfo[];
-}
+export interface ArtifactDetail extends Artifact {}
 
 export interface PaginatedResponse<T> {
   items: T[];
@@ -131,8 +94,6 @@ export interface ListParams {
   order?: 'asc' | 'desc';
 }
 
-export interface TagListParams extends ListParams {}
-
 export interface PackageListParams extends ListParams {
   format?: string;
   platform?: string;
@@ -157,7 +118,6 @@ export interface UploadResponse {
   size: number;
   project: string;
   package: string;
-  tag: string | null;
   version: string | null;
   version_source: string | null;
 }
@@ -180,9 +140,8 @@ export interface SearchResultPackage {
 }
 
 export interface SearchResultArtifact {
-  tag_id: string;
-  tag_name: string;
   artifact_id: string;
+  version: string | null;
   package_id: string;
   package_name: string;
   project_name: string;
@@ -405,8 +364,7 @@ export interface Dependency {
   artifact_id: string;
   project: string;
   package: string;
-  version: string | null;
-  tag: string | null;
+  version: string;
   created_at: string;
 }
 
@@ -420,7 +378,6 @@ export interface DependentInfo {
   project: string;
   package: string;
   version: string | null;
-  constraint_type: 'version' | 'tag';
   constraint_value: string;
 }
 
@@ -443,7 +400,6 @@ export interface ResolvedArtifact {
   project: string;
   package: string;
   version: string | null;
-  tag: string | null;
   size: number;
   download_url: string;
 }

migrations/012_remove_tags.sql

@@ -0,0 +1,33 @@
+-- Migration: Remove tag system
+-- Date: 2026-02-03
+-- Description: Remove tags table and related objects, keeping only versions for artifact references
+
+-- Drop triggers on tags table
+DROP TRIGGER IF EXISTS tags_ref_count_insert_trigger ON tags;
+DROP TRIGGER IF EXISTS tags_ref_count_delete_trigger ON tags;
+DROP TRIGGER IF EXISTS tags_ref_count_update_trigger ON tags;
+DROP TRIGGER IF EXISTS tags_updated_at_trigger ON tags;
+DROP TRIGGER IF EXISTS tag_changes_trigger ON tags;
+
+-- Drop the tag change tracking function
+DROP FUNCTION IF EXISTS track_tag_changes();
+
+-- Remove tag_constraint from artifact_dependencies
+-- First drop the constraint that requires either version or tag
+ALTER TABLE artifact_dependencies DROP CONSTRAINT IF EXISTS check_constraint_type;
+
+-- Remove the tag_constraint column
+ALTER TABLE artifact_dependencies DROP COLUMN IF EXISTS tag_constraint;
+
+-- Make version_constraint NOT NULL (now the only option)
+UPDATE artifact_dependencies SET version_constraint = '*' WHERE version_constraint IS NULL;
+ALTER TABLE artifact_dependencies ALTER COLUMN version_constraint SET NOT NULL;
+
+-- Drop tag_history table first (depends on tags)
+DROP TABLE IF EXISTS tag_history;
+
+-- Drop tags table
+DROP TABLE IF EXISTS tags;
+
+-- Rename uploads.tag_name to uploads.version (historical data field)
+ALTER TABLE uploads RENAME COLUMN tag_name TO version;