Claude API: Anthropic Messages and Claude Code
The Claude API uses the Anthropic Messages format and pairs well with Claude Code and agent workflows that lean on long, structured reasoning and tool use.
Comparison
Claude API vs GPT API
Compare both — and use either through one gateway.
A practical look at the Claude API and GPT API for coding tools and agents, plus how to use both through a single OpenAI-compatible gateway so you can switch models without switching providers.
GPT API: Responses API and Chat Completions
The GPT API offers the OpenAI Responses API and Chat Completions, with a broad ecosystem of SDKs and tooling that many existing apps already target.
Why not both, through one gateway
Instead of choosing once, route both Claude and GPT (and Gemini) through one OpenAI-compatible endpoint, then pick per task while keeping one key, one bill and one set of usage logs.
Can I use Claude and GPT with the same integration?
Yes. Through the gateway you can reach both via one endpoint and key, switching models per request.
Which is better for coding agents?
Both are strong; many teams route reasoning-heavy steps to Claude and broad tooling steps to GPT. The gateway lets you test both without re-integrating.
Does switching models change billing?
No. Usage logs and billing stay unified across models, with tokens and cost reported per request.