Mercury 2
Mercury 2 is an extremely fast reasoning LLM, and the first reasoning diffusion LLM (dLLM). Instead of generating tokens sequentially, Mercury 2 produces and refines multiple tokens in parallel, achieving >1,000 tokens/sec on standard GPUs. Mercury 2 is 5x+ faster than leading speed-optimized LLMs like Claude 4.5 Haiku and GPT 5 Mini, at a fraction of the cost. Mercury 2 supports tunable reasoning levels, 128K context, native tool use, and schema-aligned JSON output. Built for coding workflows where latency compounds, real-time voice/search, and agent loops. OpenAI API compatible. Read more in the [blog post](https://www.inceptionlabs.ai/blog/introducing-mercury-2).
Specifications
Modalities
Supported Parameters
Max Output Tokens
50,000Reasoning Configuration
- Default
- Thinking on (effort: medium)
- Selectable effort levels
- highmediumlownone
- Turning thinking off
- Possible (reasoning.enabled: false)
Data policy
- Prompt retention
- Unknown — we could not confirm
- Training
- Unknown — not declared
"Unknown" does not mean "safe". It means we could not confirm it.
Whether a provider trains on prompts is a declared value from our terms with them. Retention is determined from the upstream listing for every host this model can reach. Neither is guessed.
Frequently asked questions
- Is Mercury 2 available on FastMetal?
- Not at the moment. Mercury 2.5, from the same lab, is available on the FastMetal API today.
- What is the context window of Mercury 2?
- 128,000 tokens, shared between the prompt and the response.