> This page is for Release Notes.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://mailchimp.com/developer/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://mailchimp.com/developer/_mcp/server.

# Batch API limit now considers pending batch webhooks

We now allow a user to submit up to 500 pending API batches. For each completed batch, we send those results to each batch webhook that has been created. A user will not be able to create more API batches if there are 500 outstanding batch webhooks that have yet to complete. A 429 status code will be returned in this instance.

Previously, we did not have a limit on how many batch webhooks could be instantiated for a given user. This unbounded nature can have an impact on the performance of the API, which this new limit will help mitigate.