chroma-core/chroma · error · TypeError

Unsupported select input

Error message

Unsupported select input

What it means

Thrown by Select.from (select.ts:48) when the input is a shape the parser does not recognize: not a Select instance, not null/undefined, not an iterable, and not an object with a `keys` property. Note the subtlety: a plain string IS iterable, so Select.from('doc') does not throw — it silently becomes Select(['d','o','c']). This error is reserved for primitives (numbers, booleans), functions, and objects lacking both Symbol.iterator and keys.

Source

Thrown at clients/new-js/packages/chromadb/src/execution/expression/select.ts:48

    }

    if (input === null || input === undefined) {
      return new Select();
    }

    if (Symbol.iterator in Object(input)) {
      return new Select(input as Iterable<SelectKeyInput>);
    }

    if (
      typeof input === "object" &&
      "keys" in (input as Record<string, unknown>)
    ) {
      const { keys } = input as { keys?: Iterable<SelectKeyInput> };
      return new Select(keys ?? []);
    }

    throw new TypeError("Unsupported select input");
  }

  public static all(): Select {
    return new Select([Key.DOCUMENT, Key.EMBEDDING, Key.METADATA, Key.SCORE]);
  }

  public get values(): string[] {
    return this.keys.slice();
  }

  public toJSON(): { keys: string[] } {
    return { keys: this.values };
  }
}

View on GitHub (pinned to aecdd12c8a)

Solutions

1. Pass an array of string/Key entries: Select.from(['#document'])
2. Or the wrapper object with the exact `keys` property: Select.from({ keys: ['#document'] })
3. For 'select everything' use Select.all() or pass null/undefined (empty Select)
4. Validate external input before handing it to Select.from

Example fix

// before
const select = Select.from(payload.select); // payload.select = { fields: ['doc'] }

// after
const select = Select.from(
  Array.isArray(payload.select) ? payload.select : payload.select?.keys,
);

const toSelectInput = (v: unknown) =>
  v == null || Array.isArray(v) || typeof v === 'object'
    ? v
    : Select.all();
const select = Select.from(toSelectInput(payload.select));

const isSelectInputLike = (v: unknown): v is SelectInput =>
  v == null ||
  v instanceof Select ||
  (typeof v === 'object' &&
    (Symbol.iterator in v || 'keys' in (v as Record<string, unknown>)));

try {
  const select = Select.from(payload.select);
} catch (e) {
  if (e instanceof TypeError && e.message.includes('Unsupported select')) {
    return new Select(); // empty = no explicit selection
  }
  throw e;
}

When it happens

Trigger: Select.from(42); Select.from(true); Select.from(() => {}); Select.from({ fields: ['a'] }) — wrong property name, must be `keys`; passing a parsed JSON value that is a number or boolean instead of the expected object.

Common situations: API/config payload drift where `select` is expected to be an array or {keys: [...]} but arrives as a scalar; typos in the wrapper property (fields/columns instead of keys); passing a Boolean flag meaning 'select all' instead of Select.all() or null.

Related errors

• Select keys must be strings or Key instances
• Knn limit must be a positive integer
• Knn key must be a string or Key instance
• Rrf k must be a positive integer
• Where input must be a WhereExpression or plain object

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/4bbb1df5efee561c. Report an issue: GitHub.