feat(vendor): add contact info inheritance from company

Vendors can now override company contact information for specific branding.
Fields are nullable - if null, value is inherited from parent company.

Database changes:
- Add vendor.contact_email, contact_phone, website, business_address, tax_number
- All nullable (null = inherit from company)
- Alembic migration: 28d44d503cac

Model changes:
- Add effective_* properties for resolved values
- Add get_contact_info_with_inheritance() helper

Schema changes:
- VendorCreate: Optional contact fields for override at creation
- VendorUpdate: Contact fields + reset_contact_to_company flag
- VendorDetailResponse: Resolved values + *_inherited flags

API changes:
- GET/PUT vendor endpoints return resolved contact info
- PUT accepts contact overrides (empty string = reset to inherit)
- _build_vendor_detail_response helper for consistent responses

Service changes:
- admin_service.update_vendor handles reset_contact_to_company flag
- Empty strings converted to None for inheritance

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

alembic/versions/28d44d503cac_add_contact_fields_to_vendor.py

@@ -0,0 +1,37 @@
+"""add contact fields to vendor
+
+Revision ID: 28d44d503cac
+Revises: 9f3a25ea4991
+Create Date: 2025-12-03 22:26:02.161087
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '28d44d503cac'
+down_revision: Union[str, None] = '9f3a25ea4991'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Add nullable contact fields to vendor table
+    # These allow vendor-specific branding/identity, overriding company defaults
+    op.add_column('vendors', sa.Column('contact_email', sa.String(255), nullable=True))
+    op.add_column('vendors', sa.Column('contact_phone', sa.String(50), nullable=True))
+    op.add_column('vendors', sa.Column('website', sa.String(255), nullable=True))
+    op.add_column('vendors', sa.Column('business_address', sa.Text(), nullable=True))
+    op.add_column('vendors', sa.Column('tax_number', sa.String(100), nullable=True))
+
+
+def downgrade() -> None:
+    # Remove contact fields from vendor table
+    op.drop_column('vendors', 'tax_number')
+    op.drop_column('vendors', 'business_address')
+    op.drop_column('vendors', 'website')
+    op.drop_column('vendors', 'contact_phone')
+    op.drop_column('vendors', 'contact_email')

app/api/v1/admin/vendors.py

@@ -116,23 +116,14 @@ def get_vendor_statistics_endpoint(
     )
 
 
-@router.get("/{vendor_identifier}", response_model=VendorDetailResponse)
+def _build_vendor_detail_response(vendor) -> VendorDetailResponse:
-def get_vendor_details(
-    vendor_identifier: str = Path(..., description="Vendor ID or vendor_code"),
-    db: Session = Depends(get_db),
-    current_admin: User = Depends(get_current_admin_api),
-):
     """
-    Get detailed vendor information including company and owner details (Admin only).
+    Helper to build VendorDetailResponse with resolved contact info.
 
-    Accepts either vendor ID (integer) or vendor_code (string).
+    Contact fields are resolved using vendor override or company fallback.
-
+    Inheritance flags indicate if value comes from company.
-    Returns vendor info with company contact details and owner info.
-
-    Raises:
-        VendorNotFoundException: If vendor not found (404)
     """
-    vendor = vendor_service.get_vendor_by_identifier(db, vendor_identifier)
+    contact_info = vendor.get_contact_info_with_inheritance()
 
     return VendorDetailResponse(
         # Vendor fields
@@ -151,15 +142,39 @@ def get_vendor_details(
         updated_at=vendor.updated_at,
         # Company info
         company_name=vendor.company.name,
-        company_contact_email=vendor.company.contact_email,
-        company_contact_phone=vendor.company.contact_phone,
-        company_website=vendor.company.website,
         # Owner details (from company)
         owner_email=vendor.company.owner.email,
         owner_username=vendor.company.owner.username,
+        # Resolved contact info with inheritance flags
+        **contact_info,
+        # Original company values for UI reference
+        company_contact_email=vendor.company.contact_email,
+        company_contact_phone=vendor.company.contact_phone,
+        company_website=vendor.company.website,
     )
 
 
+@router.get("/{vendor_identifier}", response_model=VendorDetailResponse)
+def get_vendor_details(
+    vendor_identifier: str = Path(..., description="Vendor ID or vendor_code"),
+    db: Session = Depends(get_db),
+    current_admin: User = Depends(get_current_admin_api),
+):
+    """
+    Get detailed vendor information including company and owner details (Admin only).
+
+    Accepts either vendor ID (integer) or vendor_code (string).
+
+    Returns vendor info with company contact details, owner info, and
+    resolved contact fields (vendor override or company default).
+
+    Raises:
+        VendorNotFoundException: If vendor not found (404)
+    """
+    vendor = vendor_service.get_vendor_by_identifier(db, vendor_identifier)
+    return _build_vendor_detail_response(vendor)
+
+
 @router.put("/{vendor_identifier}", response_model=VendorDetailResponse)
 def update_vendor(
     vendor_identifier: str = Path(..., description="Vendor ID or vendor_code"),
@@ -176,40 +191,18 @@ def update_vendor(
     - Basic info: name, description, subdomain
     - Marketplace URLs
     - Status: is_active, is_verified
+    - Contact info: contact_email, contact_phone, website, business_address, tax_number
+      (these override company defaults; set to empty to reset to inherit)
 
     **Cannot update:**
     - `vendor_code` (immutable)
-    - Business contact info (use company update endpoints)
 
     Raises:
         VendorNotFoundException: If vendor not found (404)
     """
     vendor = vendor_service.get_vendor_by_identifier(db, vendor_identifier)
     vendor = admin_service.update_vendor(db, vendor.id, vendor_update)
-
+    return _build_vendor_detail_response(vendor)
-    return VendorDetailResponse(
-        id=vendor.id,
-        vendor_code=vendor.vendor_code,
-        subdomain=vendor.subdomain,
-        name=vendor.name,
-        description=vendor.description,
-        company_id=vendor.company_id,
-        letzshop_csv_url_fr=vendor.letzshop_csv_url_fr,
-        letzshop_csv_url_en=vendor.letzshop_csv_url_en,
-        letzshop_csv_url_de=vendor.letzshop_csv_url_de,
-        is_active=vendor.is_active,
-        is_verified=vendor.is_verified,
-        created_at=vendor.created_at,
-        updated_at=vendor.updated_at,
-        # Company info
-        company_name=vendor.company.name,
-        company_contact_email=vendor.company.contact_email,
-        company_contact_phone=vendor.company.contact_phone,
-        company_website=vendor.company.website,
-        # Owner details (from company)
-        owner_email=vendor.company.owner.email,
-        owner_username=vendor.company.owner.username,
-    )
 
 
 # NOTE: Ownership transfer is now at the Company level.
@@ -243,29 +236,7 @@ def toggle_vendor_verification(
         db.commit()  # ✅ ARCH: Commit at API level for transaction control
         logger.info(f"Vendor verification updated: {message}")
 
-    return VendorDetailResponse(
+    return _build_vendor_detail_response(vendor)
-        id=vendor.id,
-        vendor_code=vendor.vendor_code,
-        subdomain=vendor.subdomain,
-        name=vendor.name,
-        description=vendor.description,
-        company_id=vendor.company_id,
-        letzshop_csv_url_fr=vendor.letzshop_csv_url_fr,
-        letzshop_csv_url_en=vendor.letzshop_csv_url_en,
-        letzshop_csv_url_de=vendor.letzshop_csv_url_de,
-        is_active=vendor.is_active,
-        is_verified=vendor.is_verified,
-        created_at=vendor.created_at,
-        updated_at=vendor.updated_at,
-        # Company info
-        company_name=vendor.company.name,
-        company_contact_email=vendor.company.contact_email,
-        company_contact_phone=vendor.company.contact_phone,
-        company_website=vendor.company.website,
-        # Owner details (from company)
-        owner_email=vendor.company.owner.email,
-        owner_username=vendor.company.owner.username,
-    )
 
 
 @router.put("/{vendor_identifier}/status", response_model=VendorDetailResponse)
@@ -294,29 +265,7 @@ def toggle_vendor_status(
         db.commit()  # ✅ ARCH: Commit at API level for transaction control
         logger.info(f"Vendor status updated: {message}")
 
-    return VendorDetailResponse(
+    return _build_vendor_detail_response(vendor)
-        id=vendor.id,
-        vendor_code=vendor.vendor_code,
-        subdomain=vendor.subdomain,
-        name=vendor.name,
-        description=vendor.description,
-        company_id=vendor.company_id,
-        letzshop_csv_url_fr=vendor.letzshop_csv_url_fr,
-        letzshop_csv_url_en=vendor.letzshop_csv_url_en,
-        letzshop_csv_url_de=vendor.letzshop_csv_url_de,
-        is_active=vendor.is_active,
-        is_verified=vendor.is_verified,
-        created_at=vendor.created_at,
-        updated_at=vendor.updated_at,
-        # Company info
-        company_name=vendor.company.name,
-        company_contact_email=vendor.company.contact_email,
-        company_contact_phone=vendor.company.contact_phone,
-        company_website=vendor.company.website,
-        # Owner details (from company)
-        owner_email=vendor.company.owner.email,
-        owner_username=vendor.company.owner.username,
-    )
 
 
 @router.delete("/{vendor_identifier}")

app/services/admin_service.py

@@ -369,6 +369,21 @@ class AdminService:
             # Get update data
             update_data = vendor_update.model_dump(exclude_unset=True)
 
+            # Handle reset_contact_to_company flag
+            if update_data.pop("reset_contact_to_company", False):
+                # Reset all contact fields to None (inherit from company)
+                update_data["contact_email"] = None
+                update_data["contact_phone"] = None
+                update_data["website"] = None
+                update_data["business_address"] = None
+                update_data["tax_number"] = None
+
+            # Convert empty strings to None for contact fields (empty = inherit)
+            contact_fields = ["contact_email", "contact_phone", "website", "business_address", "tax_number"]
+            for field in contact_fields:
+                if field in update_data and update_data[field] == "":
+                    update_data[field] = None
+
             # Check subdomain uniqueness if changing
             if (
                 "subdomain" in update_data

docs/development/migration/vendor-contact-inheritance.md

@@ -0,0 +1,301 @@
+# Vendor Contact Inheritance Migration
+
+## Overview
+
+**Feature:** Add contact information fields to Vendor model with inheritance from Company.
+
+**Pattern:** Nullable with Fallback - Vendor fields are nullable; if null, inherit from parent company at read time.
+
+**Benefits:**
+- Vendors inherit company contact info by default
+- Can override specific fields for vendor-specific branding/identity
+- Can reset to "inherit from company" by setting field to null
+- Company updates automatically reflect in vendors that haven't overridden
+
+---
+
+## Database Changes
+
+### New Columns in `vendor` Table
+
+| Column | Type | Nullable | Default | Description |
+|--------|------|----------|---------|-------------|
+| `contact_email` | VARCHAR(255) | Yes | NULL | Override company contact email |
+| `contact_phone` | VARCHAR(50) | Yes | NULL | Override company contact phone |
+| `website` | VARCHAR(255) | Yes | NULL | Override company website |
+| `business_address` | TEXT | Yes | NULL | Override company business address |
+| `tax_number` | VARCHAR(100) | Yes | NULL | Override company tax number |
+
+### Resolution Logic
+
+```
+effective_value = vendor.field if vendor.field is not None else vendor.company.field
+```
+
+---
+
+## Files to Modify
+
+### 1. Database Model
+- `models/database/vendor.py` - Add nullable contact fields
+
+### 2. Alembic Migration
+- `alembic/versions/xxx_add_vendor_contact_fields.py` - New migration
+
+### 3. Pydantic Schemas
+- `models/schema/vendor.py`:
+  - `VendorUpdate` - Add optional contact fields
+  - `VendorResponse` - Add resolved contact fields
+  - `VendorDetailResponse` - Add contact fields with inheritance indicator
+
+### 4. Service Layer
+- `app/services/vendor_service.py` - Add contact resolution helper
+- `app/services/admin_service.py` - Update create/update to handle contact fields
+
+### 5. API Endpoints
+- `app/api/v1/admin/vendors.py` - Update responses to include resolved contact info
+
+### 6. Frontend
+- `app/templates/admin/vendor-edit.html` - Add contact fields with inheritance toggle
+- `static/admin/js/vendor-edit.js` - Handle inheritance UI logic
+
+---
+
+## Implementation Steps
+
+### Step 1: Database Model
+
+```python
+# models/database/vendor.py
+
+class Vendor(Base):
+    # ... existing fields ...
+
+    # Contact fields (nullable = inherit from company)
+    contact_email = Column(String(255), nullable=True)
+    contact_phone = Column(String(50), nullable=True)
+    website = Column(String(255), nullable=True)
+    business_address = Column(Text, nullable=True)
+    tax_number = Column(String(100), nullable=True)
+
+    # Helper properties for resolved values
+    @property
+    def effective_contact_email(self) -> str | None:
+        return self.contact_email if self.contact_email is not None else (
+            self.company.contact_email if self.company else None
+        )
+
+    @property
+    def effective_contact_phone(self) -> str | None:
+        return self.contact_phone if self.contact_phone is not None else (
+            self.company.contact_phone if self.company else None
+        )
+
+    # ... similar for other fields ...
+```
+
+### Step 2: Alembic Migration
+
+```python
+def upgrade():
+    op.add_column('vendor', sa.Column('contact_email', sa.String(255), nullable=True))
+    op.add_column('vendor', sa.Column('contact_phone', sa.String(50), nullable=True))
+    op.add_column('vendor', sa.Column('website', sa.String(255), nullable=True))
+    op.add_column('vendor', sa.Column('business_address', sa.Text(), nullable=True))
+    op.add_column('vendor', sa.Column('tax_number', sa.String(100), nullable=True))
+
+def downgrade():
+    op.drop_column('vendor', 'tax_number')
+    op.drop_column('vendor', 'business_address')
+    op.drop_column('vendor', 'website')
+    op.drop_column('vendor', 'contact_phone')
+    op.drop_column('vendor', 'contact_email')
+```
+
+### Step 3: Pydantic Schemas
+
+```python
+# models/schema/vendor.py
+
+class VendorUpdate(BaseModel):
+    # ... existing fields ...
+
+    # Contact fields (None = don't update, empty string could mean "clear/inherit")
+    contact_email: str | None = None
+    contact_phone: str | None = None
+    website: str | None = None
+    business_address: str | None = None
+    tax_number: str | None = None
+
+class VendorContactInfo(BaseModel):
+    """Resolved contact information with inheritance indicators."""
+    contact_email: str | None
+    contact_phone: str | None
+    website: str | None
+    business_address: str | None
+    tax_number: str | None
+
+    # Inheritance flags
+    contact_email_inherited: bool = False
+    contact_phone_inherited: bool = False
+    website_inherited: bool = False
+    business_address_inherited: bool = False
+    tax_number_inherited: bool = False
+
+class VendorDetailResponse(BaseModel):
+    # ... existing fields ...
+
+    # Resolved contact info
+    contact_email: str | None
+    contact_phone: str | None
+    website: str | None
+    business_address: str | None
+    tax_number: str | None
+
+    # Inheritance indicators (for UI)
+    contact_email_inherited: bool
+    contact_phone_inherited: bool
+    website_inherited: bool
+    business_address_inherited: bool
+    tax_number_inherited: bool
+```
+
+### Step 4: Service Layer Helper
+
+```python
+# app/services/vendor_service.py
+
+def get_resolved_contact_info(self, vendor: Vendor) -> dict:
+    """
+    Get resolved contact information with inheritance flags.
+
+    Returns dict with both values and flags indicating if inherited.
+    """
+    company = vendor.company
+
+    return {
+        "contact_email": vendor.contact_email or (company.contact_email if company else None),
+        "contact_email_inherited": vendor.contact_email is None and company is not None,
+
+        "contact_phone": vendor.contact_phone or (company.contact_phone if company else None),
+        "contact_phone_inherited": vendor.contact_phone is None and company is not None,
+
+        "website": vendor.website or (company.website if company else None),
+        "website_inherited": vendor.website is None and company is not None,
+
+        "business_address": vendor.business_address or (company.business_address if company else None),
+        "business_address_inherited": vendor.business_address is None and company is not None,
+
+        "tax_number": vendor.tax_number or (company.tax_number if company else None),
+        "tax_number_inherited": vendor.tax_number is None and company is not None,
+    }
+```
+
+### Step 5: API Endpoint Updates
+
+```python
+# app/api/v1/admin/vendors.py
+
+@router.get("/{vendor_identifier}", response_model=VendorDetailResponse)
+def get_vendor_details(...):
+    vendor = vendor_service.get_vendor_by_identifier(db, vendor_identifier)
+    contact_info = vendor_service.get_resolved_contact_info(vendor)
+
+    return VendorDetailResponse(
+        # ... existing fields ...
+        **contact_info,  # Includes values and inheritance flags
+    )
+```
+
+### Step 6: Frontend UI
+
+```html
+<!-- Vendor edit form with inheritance toggle -->
+<label class="block text-sm">
+    <span class="text-gray-700 dark:text-gray-400">
+        Contact Email
+        <span x-show="contactEmailInherited" class="text-xs text-purple-500">(inherited from company)</span>
+    </span>
+    <div class="flex gap-2">
+        <input type="email" x-model="formData.contact_email"
+               :placeholder="companyContactEmail"
+               :class="{ 'bg-gray-100': contactEmailInherited }">
+        <button type="button" @click="resetToCompany('contact_email')"
+                x-show="!contactEmailInherited"
+                class="text-sm text-purple-600">
+            Reset to Company
+        </button>
+    </div>
+</label>
+```
+
+---
+
+## API Behavior
+
+### GET /api/v1/admin/vendors/{id}
+
+Returns resolved contact info with inheritance flags:
+
+```json
+{
+  "id": 1,
+  "vendor_code": "VENDOR001",
+  "name": "My Vendor",
+  "contact_email": "sales@company.com",
+  "contact_email_inherited": true,
+  "contact_phone": "+352 123 456",
+  "contact_phone_inherited": false,
+  "website": "https://company.com",
+  "website_inherited": true
+}
+```
+
+### PUT /api/v1/admin/vendors/{id}
+
+To override a field:
+```json
+{
+  "contact_email": "vendor-specific@example.com"
+}
+```
+
+To reset to inherit from company (set to null):
+```json
+{
+  "contact_email": null
+}
+```
+
+---
+
+## Testing Plan
+
+1. **Create vendor** - Verify contact fields are null (inheriting)
+2. **Read vendor** - Verify resolved values come from company
+3. **Update vendor contact** - Verify override works
+4. **Reset to inherit** - Verify setting null restores inheritance
+5. **Update company** - Verify change reflects in inheriting vendors
+6. **Update company** - Verify change does NOT affect overridden vendors
+
+---
+
+## Rollback Plan
+
+If issues occur:
+1. Run downgrade migration: `alembic downgrade -1`
+2. Revert code changes
+3. Re-deploy
+
+---
+
+## Progress Tracking
+
+- [ ] Database model updated
+- [ ] Alembic migration created and applied
+- [ ] Pydantic schemas updated
+- [ ] Service layer helper added
+- [ ] API endpoints updated
+- [ ] Frontend forms updated
+- [ ] Tests written and passing
+- [ ] Documentation updated

models/database/vendor.py

@@ -63,6 +63,17 @@ class Vendor(Base, TimestampMixin):
         Boolean, default=False
     )  # Boolean to indicate if the vendor brand is verified
 
+    # ========================================================================
+    # Contact Information (nullable = inherit from company)
+    # ========================================================================
+    # These fields allow vendor-specific branding/identity.
+    # If null, the value is inherited from the parent company.
+    contact_email = Column(String(255), nullable=True)  # Override company contact email
+    contact_phone = Column(String(50), nullable=True)  # Override company contact phone
+    website = Column(String(255), nullable=True)  # Override company website
+    business_address = Column(Text, nullable=True)  # Override company business address
+    tax_number = Column(String(100), nullable=True)  # Override company tax number
+
     # ========================================================================
     # Relationships
     # ========================================================================
@@ -202,6 +213,66 @@ class Vendor(Base, TimestampMixin):
                 domains.append(domain.domain)  # Add other active custom domains
         return domains
 
+    # ========================================================================
+    # Contact Resolution Helper Properties
+    # ========================================================================
+    # These properties return the effective value (vendor override or company fallback)
+
+    @property
+    def effective_contact_email(self) -> str | None:
+        """Get contact email (vendor override or company fallback)."""
+        if self.contact_email is not None:
+            return self.contact_email
+        return self.company.contact_email if self.company else None
+
+    @property
+    def effective_contact_phone(self) -> str | None:
+        """Get contact phone (vendor override or company fallback)."""
+        if self.contact_phone is not None:
+            return self.contact_phone
+        return self.company.contact_phone if self.company else None
+
+    @property
+    def effective_website(self) -> str | None:
+        """Get website (vendor override or company fallback)."""
+        if self.website is not None:
+            return self.website
+        return self.company.website if self.company else None
+
+    @property
+    def effective_business_address(self) -> str | None:
+        """Get business address (vendor override or company fallback)."""
+        if self.business_address is not None:
+            return self.business_address
+        return self.company.business_address if self.company else None
+
+    @property
+    def effective_tax_number(self) -> str | None:
+        """Get tax number (vendor override or company fallback)."""
+        if self.tax_number is not None:
+            return self.tax_number
+        return self.company.tax_number if self.company else None
+
+    def get_contact_info_with_inheritance(self) -> dict:
+        """
+        Get all contact info with inheritance flags.
+
+        Returns dict with resolved values and flags indicating if inherited from company.
+        """
+        company = self.company
+        return {
+            "contact_email": self.effective_contact_email,
+            "contact_email_inherited": self.contact_email is None and company is not None,
+            "contact_phone": self.effective_contact_phone,
+            "contact_phone_inherited": self.contact_phone is None and company is not None,
+            "website": self.effective_website,
+            "website_inherited": self.website is None and company is not None,
+            "business_address": self.effective_business_address,
+            "business_address_inherited": self.business_address is None and company is not None,
+            "tax_number": self.effective_tax_number,
+            "tax_number_inherited": self.tax_number is None and company is not None,
+        }
+
 
 class VendorUserType(str, enum.Enum):
     """Types of vendor users."""

models/schema/vendor.py

@@ -25,7 +25,8 @@ class VendorCreate(BaseModel):
     """
     Schema for creating a new vendor (storefront/brand) under an existing company.
 
-    Business contact info is inherited from the parent company.
+    Contact info is inherited from the parent company by default.
+    Optionally, provide contact fields to override from the start.
     """
 
     # Parent company
@@ -51,6 +52,13 @@ class VendorCreate(BaseModel):
     letzshop_csv_url_en: str | None = Field(None, description="English CSV URL")
     letzshop_csv_url_de: str | None = Field(None, description="German CSV URL")
 
+    # Contact Info (optional - if not provided, inherited from company)
+    contact_email: str | None = Field(None, description="Override company contact email")
+    contact_phone: str | None = Field(None, description="Override company contact phone")
+    website: str | None = Field(None, description="Override company website")
+    business_address: str | None = Field(None, description="Override company business address")
+    tax_number: str | None = Field(None, description="Override company tax number")
+
     @field_validator("subdomain")
     @classmethod
     def validate_subdomain(cls, v):
@@ -72,8 +80,8 @@ class VendorUpdate(BaseModel):
     """
     Schema for updating vendor information (Admin only).
 
-    Note: Business contact info (contact_email, etc.) is at the Company level.
+    Contact fields can be overridden at the vendor level.
-    Use company update endpoints to modify those fields.
+    Set to null/empty to reset to company default (inherit).
     """
 
     # Basic Information
@@ -90,6 +98,18 @@ class VendorUpdate(BaseModel):
     is_active: bool | None = None
     is_verified: bool | None = None
 
+    # Contact Info (set value to override, set to empty string to reset to inherit)
+    contact_email: str | None = Field(None, description="Override company contact email")
+    contact_phone: str | None = Field(None, description="Override company contact phone")
+    website: str | None = Field(None, description="Override company website")
+    business_address: str | None = Field(None, description="Override company business address")
+    tax_number: str | None = Field(None, description="Override company tax number")
+
+    # Special flag to reset contact fields to inherit from company
+    reset_contact_to_company: bool | None = Field(
+        None, description="If true, reset all contact fields to inherit from company"
+    )
+
     @field_validator("subdomain")
     @classmethod
     def subdomain_lowercase(cls, v):
@@ -135,16 +155,14 @@ class VendorResponse(BaseModel):
 
 class VendorDetailResponse(VendorResponse):
     """
-    Extended vendor response including company information.
+    Extended vendor response including company information and resolved contact info.
 
-    Includes company details like contact info and owner information.
+    Contact fields show the effective value (vendor override or company default)
+    with flags indicating if the value is inherited from the parent company.
     """
 
     # Company info
     company_name: str = Field(..., description="Name of the parent company")
-    company_contact_email: str = Field(..., description="Company business contact email")
-    company_contact_phone: str | None = Field(None, description="Company phone number")
-    company_website: str | None = Field(None, description="Company website URL")
 
     # Owner info (at company level)
     owner_email: str = Field(
@@ -152,6 +170,25 @@ class VendorDetailResponse(VendorResponse):
     )
     owner_username: str = Field(..., description="Username of the company owner")
 
+    # Resolved contact info (vendor override or company default)
+    contact_email: str | None = Field(None, description="Effective contact email")
+    contact_phone: str | None = Field(None, description="Effective contact phone")
+    website: str | None = Field(None, description="Effective website")
+    business_address: str | None = Field(None, description="Effective business address")
+    tax_number: str | None = Field(None, description="Effective tax number")
+
+    # Inheritance flags (True = value is inherited from company, not overridden)
+    contact_email_inherited: bool = Field(False, description="True if contact_email is from company")
+    contact_phone_inherited: bool = Field(False, description="True if contact_phone is from company")
+    website_inherited: bool = Field(False, description="True if website is from company")
+    business_address_inherited: bool = Field(False, description="True if business_address is from company")
+    tax_number_inherited: bool = Field(False, description="True if tax_number is from company")
+
+    # Original company values (for reference in UI)
+    company_contact_email: str | None = Field(None, description="Company's contact email")
+    company_contact_phone: str | None = Field(None, description="Company's phone number")
+    company_website: str | None = Field(None, description="Company's website URL")
+
 
 class VendorCreateResponse(VendorDetailResponse):
     """