Facts read November 7, 2026
Claude API vs OpenAI API
OpenAI API is Cuely's default ai model api pick when your description doesn't favor either one: the widest ecosystem of examples and libraries, with a very cheap small model. Pick Claude API if you care most about answering from documents.
Side by side
| Fact | Claude API | OpenAI API |
|---|---|---|
| What it is | Anthropic's model API (Claude Opus, Sonnet and Haiku models). | OpenAI's model API (GPT models). |
| Free plan | None | None |
| Paid from | Haiku 5.5: $0.10 per million input tokens, $0.50 output (prompts up to 100k). Sonnet 5.5: $2 input, $10 output. Opus 5.5: $4 input, $20 output. Sonnet cache reads: $0.10 per million. | gpt-6-luna: $0.10 per million input tokens, $0.50 output. gpt-6.1-sol: $2 input, $10 output. gpt-6-astra: $10 input, $50 output. |
| At 1,000 users | $650/month | $650/month |
| Open source | No | No |
| Self-hostable | No | No |
| Best for | Answering from documents with citations; Agents and tool use; A cheap small model (Haiku) for simple requests | The most third-party examples and SDK support; A cheap small model for simple requests |
| Watch out | No permanent free tier; new accounts get a small test credit. Haiku 5.5 costs 5 times more for prompts over 100,000 tokens ($0.50 in, $2.50 out). | Model names and prices change often; Cuely's read of the pricing table was partial, so confirm the model you pick on the page. |
Where they differ
The published scores, from −3 to +3, that decide which one Cuely picks for each need.
| Need | Claude API | OpenAI API |
|---|---|---|
| answers over the user's own documents | +1 Built-in citations and PDF input help answer from documents; cache reads cost 5% of input. | 0 No particular strength here. |
Sources: Claude API pricing (read November 7, 2026), OpenAI API pricing (read November 7, 2026). No vendor pays for placement.