curl -X GET "https://api.omophub.com/v1/vocabularies/SNOMED/changelog?from_version=2024-01&to_version=2024-03&change_types=added,modified&include_details=true&include_impact_analysis=true" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json"

{
  "success": true,
  "data": {
    "vocabulary_id": "SNOMED",
    "vocabulary_name": "Systematized Nomenclature of Medicine Clinical Terms",
    "from_version": "2024-01",
    "to_version": "2024.2",
    "summary": {
      "total_changes": 4876,
      "change_type_breakdown": {
        "added": 2847,
        "modified": 1523,
        "deprecated": 89,
        "deleted": 12,
        "reactivated": 156,
        "relationship_changes": 249
      },
      "domains_affected": [
        "Condition",
        "Procedure", 
        "Observation",
        "Measurement",
        "Drug"
      ],
      "impact_level": "Medium"
    },
    "changes": [
      {
        "concept_id": "1240541000000107",
        "concept_code": "1240541000000107",
        "concept_name": "COVID-19 Omicron variant BA.5 infection",
        "change_type": "added",
        "change_date": "2024-03-01T00:00:00Z",
        "version": "2024.2",
        "domain_id": "Condition",
        "concept_class_id": "Clinical Finding",
        "change_description": "New concept added for COVID-19 Omicron BA.5 variant",
        "change_details": {
          "old_values": null,
          "new_values": {
            "concept_name": "COVID-19 Omicron variant BA.5 infection",
            "concept_code": "1240541000000107",
            "valid_start_date": "2024-03-01",
            "standard_concept": "S"
          },
          "fields_changed": ["all"],
          "relationship_changes": [
            {
              "relationship_type": "Is a",
              "target_concept_id": "840539006",
              "target_concept_name": "Disease caused by severe acute respiratory syndrome coronavirus 2"
            }
          ],
          "synonym_changes": [
            {
              "change_type": "added",
              "synonym": "BA.5 COVID infection",
              "language": "en"
            }
          ]
        },
        "impact_analysis": {
          "severity": "Low",
          "affected_mappings": 0,
          "affected_descendants": 0,
          "breaking_change": false,
          "migration_required": false,
          "recommendations": [
            "Consider updating clinical decision support rules",
            "Review variant-specific coding guidelines"
          ]
        },
        "replacement_concept": null
      },
      {
        "concept_id": "84757009",
        "concept_code": "84757009",
        "concept_name": "Epilepsy (disorder)",
        "change_type": "modified",
        "change_date": "2024-03-01T00:00:00Z",
        "version": "2024.2",
        "domain_id": "Condition",
        "concept_class_id": "Clinical Finding",
        "change_description": "Updated relationships and synonyms for epilepsy concept",
        "change_details": {
          "old_values": {
            "synonym_count": 12
          },
          "new_values": {
            "synonym_count": 15
          },
          "fields_changed": ["synonyms"],
          "relationship_changes": [
            {
              "change_type": "added",
              "relationship_type": "Finding site",
              "target_concept_id": "12738006"
              "target_concept_name": "Brain structure"
            }
          ],
          "synonym_changes": [
            {
              "change_type": "added",
              "synonym": "Epileptic disorder",
              "language": "en"
            },
            {
              "change_type": "added",
              "synonym": "Seizure disorder",
              "language": "en"
            }
          ]
        },
        "impact_analysis": {
          "severity": "Low",
          "affected_mappings": 89,
          "affected_descendants": 234,
          "breaking_change": false,
          "migration_required": false,
          "recommendations": [
            "No action required for existing implementations",
            "Enhanced synonyms may improve search capabilities"
          ]
        },
        "replacement_concept": null
      },
      {
        "concept_id": "123456789",
        "concept_code": "123456789",
        "concept_name": "Legacy cardiac procedure (deprecated)",
        "change_type": "deprecated",
        "change_date": "2024-03-01T00:00:00Z",
        "version": "2024.2",
        "domain_id": "Procedure",
        "concept_class_id": "Procedure",
        "change_description": "Deprecated in favor of more specific cardiac intervention concepts",
        "change_details": {
          "old_values": {
            "valid_end_date": "2099-12-31",
            "invalid_reason": null
          },
          "new_values": {
            "valid_end_date": "2024-02-29",
            "invalid_reason": "D"
          },
          "fields_changed": ["valid_end_date", "invalid_reason"],
          "relationship_changes": [],
          "synonym_changes": []
        },
        "impact_analysis": {
          "severity": "Medium",
          "affected_mappings": 23,
          "affected_descendants": 0,
          "breaking_change": true,
          "migration_required": true,
          "recommendations": [
            "Migrate to replacement concept 987654321",
            "Update clinical documentation templates",
            "Review automated coding rules"
          ]
        },
        "replacement_concept": {
          "concept_id": "987654321",
          "concept_name": "Percutaneous cardiac intervention",
          "mapping_type": "Maps to"
        }
      }
    ]
  },
  "meta": {
    "request_id": "req_snomed_changelog_123",
    "timestamp": "2024-03-01T00:00:00Z",
    "filters_applied": {
      "from_version": "2024-01",
      "to_version": "2024.2",
      "change_types": ["added", "modified", "deprecated"],
      "include_details": true,
      "include_impact_analysis": true
    },
    "pagination": {
      "page": 1,
      "page_size": 50,
      "total_items": 4876,
      "total_pages": 98,
      "has_next": true,
      "has_previous": false
    },
    "version_range": "2024-01 to 2024-03"
  }
}