{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://www.ebi.ac.uk/chembl/schema/activity",
  "title": "ChEMBL Activity",
  "description": "A bioactivity measurement from a ChEMBL assay, linking a compound to a biological target with a quantitative or qualitative measurement.",
  "type": "object",
  "properties": {
    "activity_id": {
      "type": "integer",
      "description": "Unique numeric ID for the activity record"
    },
    "assay_chembl_id": {
      "type": "string",
      "pattern": "^CHEMBL[0-9]+$",
      "description": "ChEMBL ID of the assay"
    },
    "assay_description": {
      "type": ["string", "null"],
      "description": "Description of the assay as extracted from the source document"
    },
    "assay_type": {
      "type": ["string", "null"],
      "enum": ["B", "F", "A", "T", "P", "U", null],
      "description": "Assay type code: B=Binding, F=Functional, A=ADME, T=Toxicity, P=Physicochemical, U=Unclassified"
    },
    "bao_endpoint": {
      "type": ["string", "null"],
      "description": "BioAssay Ontology (BAO) endpoint term ID"
    },
    "bao_format": {
      "type": ["string", "null"],
      "description": "BioAssay Ontology format term ID"
    },
    "bao_label": {
      "type": ["string", "null"],
      "description": "Human-readable BAO endpoint label"
    },
    "canonical_smiles": {
      "type": ["string", "null"],
      "description": "Canonical SMILES representation of the tested compound"
    },
    "data_validity_comment": {
      "type": ["string", "null"],
      "description": "Comment on data validity or quality issues"
    },
    "document_chembl_id": {
      "type": ["string", "null"],
      "pattern": "^CHEMBL[0-9]+$",
      "description": "ChEMBL ID of the source document"
    },
    "document_journal": {
      "type": ["string", "null"],
      "description": "Journal of the source publication"
    },
    "document_year": {
      "type": ["integer", "null"],
      "description": "Year of the source publication"
    },
    "molecule_chembl_id": {
      "type": "string",
      "pattern": "^CHEMBL[0-9]+$",
      "description": "ChEMBL ID of the tested compound"
    },
    "pchembl_value": {
      "type": ["number", "null"],
      "minimum": 0,
      "maximum": 20,
      "description": "Negative log10 of the molar activity value (comparable across activity types)"
    },
    "relation": {
      "type": ["string", "null"],
      "enum": ["=", ">", "<", ">=", "<=", "~", null],
      "description": "Relationship qualifier for the original reported activity value"
    },
    "standard_flag": {
      "type": ["boolean", "null"],
      "description": "Whether this activity value was standardized"
    },
    "standard_relation": {
      "type": ["string", "null"],
      "enum": ["=", ">", "<", ">=", "<=", "~", null],
      "description": "Standardized relationship qualifier"
    },
    "standard_text_value": {
      "type": ["string", "null"],
      "description": "Standardized text value for non-numeric activities"
    },
    "standard_type": {
      "type": ["string", "null"],
      "description": "Standardized activity type (e.g., IC50, Ki, EC50, Kd, Potency)"
    },
    "standard_units": {
      "type": ["string", "null"],
      "description": "Standardized units of the activity measurement (e.g., nM, uM)"
    },
    "standard_value": {
      "type": ["number", "null"],
      "description": "Standardized numeric activity value"
    },
    "target_chembl_id": {
      "type": ["string", "null"],
      "pattern": "^CHEMBL[0-9]+$",
      "description": "ChEMBL ID of the biological target"
    },
    "target_organism": {
      "type": ["string", "null"],
      "description": "Organism of the biological target"
    },
    "target_pref_name": {
      "type": ["string", "null"],
      "description": "Preferred name of the biological target"
    },
    "target_tax_id": {
      "type": ["string", "null"],
      "description": "NCBI taxonomy ID of the target organism"
    },
    "type": {
      "type": ["string", "null"],
      "description": "Original activity type as reported in the source document"
    },
    "units": {
      "type": ["string", "null"],
      "description": "Original units as reported in the source document"
    },
    "value": {
      "type": ["string", "null"],
      "description": "Original numeric or text value as reported"
    }
  },
  "required": ["activity_id", "assay_chembl_id", "molecule_chembl_id"],
  "examples": [
    {
      "activity_id": 31863,
      "assay_chembl_id": "CHEMBL1909072",
      "assay_description": "Inhibition of human COX-2",
      "assay_type": "B",
      "canonical_smiles": "CC(=O)Oc1ccccc1C(=O)O",
      "document_chembl_id": "CHEMBL1124375",
      "document_journal": "J. Med. Chem.",
      "document_year": 1999,
      "molecule_chembl_id": "CHEMBL25",
      "pchembl_value": 4.2,
      "relation": "=",
      "standard_relation": "=",
      "standard_type": "IC50",
      "standard_units": "nM",
      "standard_value": 60000,
      "target_chembl_id": "CHEMBL301",
      "target_organism": "Homo sapiens",
      "target_pref_name": "Cyclooxygenase-2",
      "type": "IC50",
      "units": "uM",
      "value": "60"
    }
  ]
}