Vercel AI Gateway Adds Glyph Cluster Reasoning Model for Free During Stealth Period

Vercel has added Glyph Cluster to AI Gateway as a stealth reasoning model optimized for coding and long-context analysis. The model is currently free to use for teams on Pro and Enterprise plans who have purchased AI Gateway credits.

Capabilities and Limitations

Glyph Cluster handles multi-step tasks such as planning, synthesis, quantitative reasoning, and comparing material across large inputs. For coding workflows, it can review code, explain failures, debug issues, propose changes, and reason through implementation options. It supports function calling and streams responses as they are generated.

However, the model has specific constraints:

• It accepts text input only, with no support for images or files.
• Tool use is limited to function tools defined by the user.
• Structured outputs are not supported.
• Zero Data Retention (ZDR) is not available, meaning prompts and responses may be used for training and model improvement.

Integration and Access

Developers can call Glyph Cluster using the model name stealth/glyph-cluster via the AI SDK or the OpenAI-compatible Chat Completions and Responses APIs. It can also be selected in coding agents connected to AI Gateway, such as Claude Code, Codex, and Cursor, by installing the latest Vercel CLI and running setup.

AI Gateway itself provides a unified API for model calls, usage tracking, and performance optimizations like retries and failover. It reflects provider pricing with no markup and does not charge a platform fee on inference, including for Bring Your Own Key (BYOK) requests.