Bulk create spans

Create up to 500 spans in one request. Each item in logs accepts the same fields as the single-span create operation. Rows are processed independently: one invalid row does not prevent the remaining rows from being accepted. A response is 201 Created whenever at least one row is accepted, including partial success; inspect error_count and errors on every response. success_count means the row passed synchronous validation and was accepted for ingestion.

For API-key authentication, this endpoint is limited to 30 requests per minute per organization, shared across all API keys in that organization. JWT requests are limited per user. At the 500-row maximum, the API-key limit allows up to approximately 15,000 accepted rows per minute. Metadata keys beginning with _ are reserved for platform use and are omitted from customer-facing span and trace responses, so they do not round-trip through read APIs.