chroma-core/chroma · error · Error

Cannot modify #embedding. Currently not supported

Error message

Cannot modify #embedding. Currently not supported

What it means

'#embedding' holds the collection's vectors and is configured automatically by the Schema class, so deleteIndex refuses to touch it: modification of '#embedding' is currently not supported at all. Vector index settings are changed by applying a new global config via createIndex, never by deleting the '#embedding' index.

Source

Thrown at clients/new-js/packages/chromadb/src/schema.ts:596

      this.setIndexForKey(key, config as IndexConfig, true);
    }

    return this;
  }

  deleteIndex(config?: IndexConfig, key?: string): this {
    const configProvided = config !== undefined && config !== null;
    const keyProvided = key !== undefined && key !== null;

    if (!configProvided && !keyProvided) {
      throw new Error(
        "Cannot disable all indexes. Must specify either config or key.",
      );
    }

    // Disallow using special internal key #embedding
    if (keyProvided && key && key === EMBEDDING_KEY) {
      throw new Error("Cannot modify #embedding. Currently not supported");
    }

    // Only allow #document with FtsIndexConfig (to disable FTS)
    if (
      keyProvided &&
      key === DOCUMENT_KEY &&
      !(config instanceof FtsIndexConfig)
    ) {
      throw new Error(
        `Cannot delete index on special key '${key}' with this config. Only FtsIndexConfig is allowed for #document.`,
      );
    }

    // Disallow any key starting with # (except #document which allows FTS deletion)
    if (keyProvided && key && key.startsWith("#") && key !== DOCUMENT_KEY) {
      throw new Error(
        "key cannot begin with '#'. Keys starting with '#' are reserved for system use.",
      );

View on GitHub (pinned to aecdd12c8a)

Solutions

1. Do not target '#embedding' with deleteIndex; removing the embedding key's index is not supported.
2. To change vector index settings, apply a new global config: createIndex(new VectorIndexConfig(...)) with no key.
3. To fully remove it, recreate the collection with a schema built without the vector index.

Example fix

// before
schema.deleteIndex(cfg, '#embedding');

// after
schema.createIndex(new VectorIndexConfig()); // reconfigure globally instead of deleting

function deleteIndexGuarded(schema: Schema, config: IndexConfig, key: string): void {
  if (key === '#embedding') {
    throw new Error('#embedding cannot be modified — apply a global VectorIndexConfig instead');
  }
  schema.deleteIndex(config, key);
}

const isProtectedKey = (key: string): boolean => key === '#embedding';

try {
  schema.deleteIndex(config, key);
} catch (e) {
  if (e instanceof Error && e.message === 'Cannot modify #embedding. Currently not supported') {
    // skip system keys during teardown
  } else {
    throw e;
  }
}

When it happens

Trigger: schema.deleteIndex(cfg, '#embedding'); schema.deleteIndex(undefined, '#embedding'); iterating Object.keys(schema.keys) and calling deleteIndex on every key including system keys.

Common situations: Programmatic teardown loops over all schema keys; attempting to disable vector search by deleting the embedding index (separately blocked by the vector-delete restriction).

Related errors

• Cannot create index on special key '${key}'. This key is man
• key cannot begin with '#'. Keys starting with '#' are reserv
• Cannot enable all index types globally. Must specify either
• Cannot create index on special key '${key}' with this config
• Vector index cannot be enabled on specific keys. Use createI

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/8adb3fb765082ce1. Report an issue: GitHub.