Batch update (max 100)

Partial success: 207 with per-item {index, status, id | error}. Each item may carry fields_ops like a single update. fields_ops (max 50) adds text instead of replacing it: [{ "field": "<column id>" | "description", "op": "append" | "prepend", "value": "...", "separator"?: "..." }]. Text, long text and document columns and the description only; an empty field just receives the value. Text joins with a space and long text with a new line unless separator (max 20 characters, text and long text only) says otherwise; document and description take the value as plain text, each line a new paragraph after (or before) the existing ones. A field may not be both in fields (or description) and in fields_ops (400 field_op_conflict). The write lands only if the field still holds what the ops were computed from; the server re-reads and retries, then answers 409 CONFLICT. Character limits apply to the result. An append is not idempotent: send an Idempotency-Key header and a retry of the same request returns its first answer instead of appending twice (a replay carries Idempotent-Replayed: true; the same key with a different request, or while the first is still running, is 409 IDEMPOTENCY_CONFLICT, the latter with Retry-After). A 4xx wrote nothing and frees the key, so a corrected retry runs; a 5xx is kept and replayed, because the change may have been saved: read the item, then retry with a new key if it was not. A batch replays its whole 207 answer under its key, so items it ran are never run twice: retry the failed items in a new request with a new key. Long text is plain multi-line text: a value that is a whole HTML document (it opens and closes with a block tag such as <p>) is converted to plain text, so text that must keep literal tags needs any other character before or after them.

Requires the data:write token scope.