ToolsFebruary 24, 2026via Vercel Blog
GPT 5.3 Codex is now on AI Gateway
Why it matters
Vercel's AI Gateway now surfaces a new reasoning+coding hybrid model optimized for agentic software development work. For founders building AI-native dev tools, this is a capability milestone that changes what's possible in code generation and multi-step task execution.
Key signals
- GPT-5.3 Codex combines GPT-5.2-Codex coding strengths with GPT-5.2 reasoning depth
- 25% faster and more token-efficient than prior versions
- Designed for long-running agentic work: research, tool use, multi-step execution
- Mid-task steering without context loss
- Better handling of underspecified prompts for web development
- Available via Vercel AI Gateway with unified API, cost tracking, observability, and intelligent provider routing
The hook
GPT-5.3 Codex just shipped on AI Gateway — 25% faster, built for agents running production workflows end-to-end.
GPT 5.3 Codex is now available on AI Gateway. GPT 5.3 Codex brings together the coding strengths of GPT-5.2-Codex and the reasoning depth of GPT-5.2 in a single model that's 25% faster and more token-efficient.
Built for long-running agentic work, the model handles research, tool use, and multi-step…