exists_source-9.3-javascript.md

endpoint	exists_source
lang	javascript
es_version	9.3
client	@elastic/elasticsearch@9.3.0

Elasticsearch 9.3 exists_source endpoint (JavaScript example)

Use client.existsSource() to check whether a document's _source field exists. Returns false if the document does not exist or if _source is disabled for the index.

const hasSource = await client.existsSource({ index: "products", id: "prod-1" });
if (hasSource) {
  const doc = await client.getSource({ index: "products", id: "prod-1" });
  console.log(`Source available: ${doc.name}`);
} else {
  console.log("No source available");
}

When to use this

This is primarily useful when working with indices where _source may be disabled in the mapping. For most indices, client.exists() is sufficient.