Anthropic
Claude model family — the default Claude Code provider. Sonnet, Opus, Haiku.
- License
- proprietary
- Install
- env key
- Website
- https://www.anthropic.com
- GitHub
- https://github.com/anthropics
export ANTHROPIC_API_KEY=...
OpenAI
GPT-5, o-series reasoning models, and the function-calling API baseline.
- License
- proprietary
- Install
- env key
- Website
- https://openai.com
- GitHub
- https://github.com/openai
export OPENAI_API_KEY=...
When to reach for which
Anthropic — Claude model family — the default Claude Code provider. Sonnet, Opus, Haiku.
OpenAI — GPT-5, o-series reasoning models, and the function-calling API baseline.
Both sit in the AI Providers category — they're substitutes, not complements. Pick by your install constraint (MCP-native, license, hosting model) and which tag overlap matters most to your stack.