json_hooks_example.yaml

# Example configuration demonstrating JSON modification hooks
# Shows how to add, delete, and modify JSON nodes in API responses

host: "0.0.0.0"
port: 8080
log_level: "INFO"

hook_mappings:
  post_hooks:
    # ============================================================================
    # ADDING JSON NODES
    # ============================================================================

    # Add a new field to user object
    - hostname: "api.example.com"
      url_pattern: "/users/*"
      hook: "json_modify"
      params:
        path: "user.verified"
        action: "set"
        value: true

    # Add a new nested field
    - hostname: "api.example.com"
      url_pattern: "/users/*"
      hook: "json_modify"
      params:
        path: "user.profile.avatar_url"
        action: "set"
        value: "https://cdn.example.com/default-avatar.png"

    # Add metadata to response
    - hostname: "api.example.com"
      url_pattern: "/api/*"
      hook: "json_modify"
      params:
        path: "metadata.proxy_version"
        action: "set"
        value: "1.0.0"

    # Add timestamp to all API responses
    - hostname: "api.example.com"
      url_pattern: "/api/v2/*"
      hook: "json_modify"
      params:
        path: "timestamp"
        action: "set"
        value: "2024-01-01T00:00:00Z"

    # ============================================================================
    # DELETING JSON NODES
    # ============================================================================

    # Remove password field from user responses
    - hostname: "api.example.com"
      url_pattern: "/users/*"
      hook: "json_modify"
      params:
        path: "user.password"
        action: "delete"

    # Remove sensitive fields
    - hostname: "api.example.com"
      url_pattern: "/users/*"
      hook: "json_modify"
      params:
        path: "user.ssn"
        action: "delete"

    # Remove internal metadata
    - hostname: "api.example.com"
      url_pattern: "/api/*"
      hook: "json_modify"
      params:
        path: "_internal"
        action: "delete"

    # Remove API key from responses
    - hostname: "api.example.com"
      url_pattern: "/config"
      hook: "json_modify"
      params:
        path: "api_key"
        action: "delete"

    # ============================================================================
    # MODIFYING JSON NODES
    # ============================================================================

    # Change user status
    - hostname: "api.example.com"
      url_pattern: "/users/inactive/*"
      hook: "json_modify"
      params:
        path: "user.status"
        action: "set"
        value: "inactive"

    # Override API version in response
    - hostname: "api.example.com"
      url_pattern: "/api/v1/*"
      hook: "json_modify"
      params:
        path: "version"
        action: "set"
        value: "v2.0"

    # Change price in product listing
    - hostname: "api.example.com"
      url_pattern: "/products/sale/*"
      hook: "json_modify"
      params:
        path: "product.price"
        action: "set"
        value: 19.99

    # Modify array element
    - hostname: "api.example.com"
      url_pattern: "/items/*"
      hook: "json_modify"
      params:
        path: "items[0].quantity"
        action: "set"
        value: 100

    # ============================================================================
    # APPENDING TO ARRAYS
    # ============================================================================

    # Add tag to user
    - hostname: "api.example.com"
      url_pattern: "/users/*"
      hook: "json_modify"
      params:
        path: "user.tags"
        action: "append"
        value: "premium"

    # Add role to user roles array
    - hostname: "api.example.com"
      url_pattern: "/users/*/roles"
      hook: "json_modify"
      params:
        path: "roles"
        action: "append"
        value: "viewer"

    # Add notification to array
    - hostname: "api.example.com"
      url_pattern: "/notifications"
      hook: "json_modify"
      params:
        path: "notifications"
        action: "append"
        value:
          id: "new-notification"
          type: "info"
          message: "System maintenance scheduled"

    # ============================================================================
    # INCREMENTING COUNTERS
    # ============================================================================

    # Increment view count
    - hostname: "api.example.com"
      url_pattern: "/posts/*"
      hook: "json_modify"
      params:
        path: "post.views"
        action: "increment"
        value: 1

    # Increment likes
    - hostname: "api.example.com"
      url_pattern: "/posts/*/like"
      hook: "json_modify"
      params:
        path: "post.likes"
        action: "increment"
        value: 1

    # Decrement stock (negative increment)
    - hostname: "api.example.com"
      url_pattern: "/products/*/purchase"
      hook: "json_modify"
      params:
        path: "product.stock"
        action: "increment"
        value: -1

    # ============================================================================
    # COMPLEX EXAMPLES - COMBINING MULTIPLE OPERATIONS
    # ============================================================================

    # Example: Sanitize user data (remove sensitive fields, add defaults)
    # First remove password
    - hostname: "api.example.com"
      url_pattern: "/users/*/profile"
      hook: "json_modify"
      params:
        path: "password_hash"
        action: "delete"

    # Then remove email
    - hostname: "api.example.com"
      url_pattern: "/users/*/profile"
      hook: "json_modify"
      params:
        path: "email_verified_token"
        action: "delete"

    # Add public flag
    - hostname: "api.example.com"
      url_pattern: "/users/*/profile"
      hook: "json_modify"
      params:
        path: "is_public_profile"
        action: "set"
        value: true

    # Example: Transform API response structure
    # Add success status to all API responses
    - hostname: "api.example.com"
      url_pattern: "/api/v2/*"
      hook: "json_modify"
      params:
        path: "success"
        action: "set"
        value: true

    # Example: A/B Testing - modify product prices
    - hostname: "shop.example.com"
      url_pattern: "/products/*"
      hook: "json_modify"
      params:
        path: "product.original_price"
        action: "set"
        value: 29.99

    # Then set discounted price
    - hostname: "shop.example.com"
      url_pattern: "/products/*"
      hook: "json_modify"
      params:
        path: "product.sale_price"
        action: "set"
        value: 19.99

# ============================================================================
# REAL-WORLD USE CASES
# ============================================================================
#
# 1. API Response Sanitization:
#    - Remove sensitive fields (passwords, API keys, tokens)
#    - Hide internal metadata from public APIs
#
# 2. Response Enhancement:
#    - Add computed fields (e.g., full_name from first + last)
#    - Add metadata (timestamps, versions, proxy info)
#    - Add default values for missing fields
#
# 3. A/B Testing:
#    - Modify prices for different user segments
#    - Change feature flags in responses
#    - Test different API response structures
#
# 4. Analytics:
#    - Increment view counters
#    - Track API usage in response metadata
#    - Add tracking IDs to responses
#
# 5. Backward Compatibility:
#    - Transform new API format to legacy format
#    - Add deprecated fields for old clients
#    - Rename fields to match old API contracts
#
# 6. Development/Testing:
#    - Mock specific field values
#    - Force error conditions (set status to "error")
#    - Simulate different user states
#
# 7. Multi-tenancy:
#    - Add tenant IDs to all responses
#    - Filter out cross-tenant data
#    - Inject tenant-specific configuration
#
# ============================================================================