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

# What's New: Week of September 21, 2026

1. **Faster OpenAI Responses with Service Tiers**: You can now set `serviceTier` to `fast` on your OpenAI [GPT-5.6 and GPT-5.5 models](/providers/model/openai#service-tier) to request OpenAI's faster processing tier for latency-sensitive calls.

2. **Provider Request IDs for Bring Your Own Key (BYOK)**: For [BYOK](/customization/provider-keys) models, call logs now include the provider's request ID for your language model, transcriber, and voice providers, so you can share it with the provider when getting support.