Exa has released Agent Ultra, the highest effort level of its Exa Agent API. It is built for research that must run to exhaustion: large list building, entity enrichment, and questions that need thousands of sources. Exa team reports that Ultra beats Opus 5.5, GPT-6 Astra, and Perplexity Agent, each at maximum effort, on 4 research benchmarks.
Is it deployable? Yes, as a hosted API. Agent Ultra is live today on the Exa API by setting effort: "ultra". It is not open weights and cannot be self-hosted.
What is Exa Agent Ultra?
Exa Agent splits a task into subtasks and assigns subagents to research several domains at once. It routes frontier models to steps that need them and faster models where those are enough. Ultra is the mode that spends the most compute. According to the Agent Ultra docs, it runs longer than any other effort to return the most complete results.
Ultra runs typically finish complex tasks in about 30 minutes. Very hard tasks can take up to 3 hours.