Mercury 2.5
by InceptionReleased Sep 8, 2026
inception/mercury-2.5- Calls tools
- Answers in a JSON schema
- Reasons before it answers
- Caches long prompts
Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception. Instead of generating tokens sequentially, Mercury 2.5 produces and refines multiple tokens in parallel, achieving...
- Input / 1M tokens
- $0.048
- Output / 1M tokens
- $0.18
- Context
- 260K
- Longest answer
- 66K
What it costs
What each call is charged to the token's AI credit.
| Billed for | You pay |
|---|---|
| Input tokens | $0.048 / 1M |
| Output tokens | $0.18 / 1M |
| Cached input, read | $0.0048 / 1M |
A typical call
A short chat turn: 2,000 tokens in, 500 out.
- per call
- $0.0002
- calls per $20
- 108K
What it can do
From its listing. The router passes every field through.
- Reads imagesNo
- Reads files and PDFsNo
- Hears audioNo
- Calls toolsYes
- Answers in a JSON schemaYes
- Reasons before it answersYes
- Searches the webNo
- Caches long promptsYes
- Draws imagesNo
Call it
Any router key works, in the format your SDK already speaks.
import OpenAI from "openai";const ai = new OpenAI({ baseURL: "https://relayfor.si/api/v1", apiKey: process.env.RELAYFOR_ROUTER_KEY,});const reply = await ai.chat.completions.create({ model: "inception/mercury-2.5", messages: [{ role: "user", content: "Welcome the 1,000th holder in one line." }],});Specifications
What its maker and providers list for it.
- Reads
- Text
- Writes
- Text
- Context
- 260,000 tokens
- Longest answer
- 65,536 tokens
- Reasoning effort
- none to high
- Intelligence index
- 12.3 (#140 of 220 rated)
- Released
- Sep 8, 2026
- Moderation
- None
Request fields
The fields its providers accept, passed through as you send them.
- include_reasoning
- max_tokens
- reasoning
- reasoning_effort
- response_format
- stop
- structured_outputs
- temperature
- tool_choice
- tools
Questions
How much does Mercury 2.5 cost?
$0.048 per million input tokens and $0.18 per million output tokens, paid from the token's AI credit. A call of 2,000 tokens in and 500 out costs about $0.0002.
How do I call Mercury 2.5?
Make a router key for one of your tokens on the dashboard, point any OpenAI or Anthropic SDK at https://relayfor.si/api/v1 and send the model id inception/mercury-2.5. The token's AI credit pays for each call.
How long a prompt can Mercury 2.5 take?
Up to 260,000 tokens of context, and up to 65,536 tokens in one answer.
Are my prompts stored?
No. The RFS Router passes each call through and keeps only its token counts and cost, for the token's usage page.
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