Five-person startup Paper Instruments releases Ultramarine 1 Flash, claims Fable-class at 60x lower cost
The gist
Paper Instruments released Ultramarine 1 Flash, claiming it beats Claude Fable 5 on four of six knowledge-work benchmarks at $0.13 per task.
All scores and costs are the vendor's own.
How it unfolded
- Aug 26, 2026Z.ai releases GLM-5.3 Flash, the base model behind Ultramarine 1 Flash, under an MIT open-source license.
- Oct 14, 2026Paper Instruments publishes Ultramarine 1 Flash and opens API access the same day, at $0.15 per million input tokens and $0.50 per million output tokens.
- Oct 14, 2026The Kobeissi Letter reports that open-source models such as DeepSeek V4 Pro cost over 50 times less per token than Anthropic Fable 5, citing Ultramarine 1 Flash as matching Fable 5 at 60x lower cost after $300k of training.