Mercury 2 API128K context
Mercury 2 is an extremely fast reasoning LLM, and the first reasoning diffusion LLM (dLLM).
Pricing & specs mirror our live pricing as of July 2026 (pay-as-you-go).
What is 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...
Mercury 2 pricing
Pay-as-you-go on DataLLM Lab — these are our live list prices (identical to the pricing page):
| Model | Input / 1M | Output / 1M | Cache read | Cache write | Context |
|---|---|---|---|---|---|
| Mercury 2 | $0.25 | $0.75 | $0.02 | — | 128K |
On output price, Mercury 2 is cheaper than 69% of the 309 models in the catalog.
What Mercury 2 costs per month
| Workload | Tokens in / out (monthly) | Est. cost |
|---|---|---|
| Support chatbot | 40M / 12M | $19.00 |
| RAG / knowledge base | 200M / 20M | $65.00 |
| Coding agent | 80M / 25M | $38.75 |
| Batch extraction | 150M / 8M | $43.50 |
| Content generation | 20M / 40M | $35.00 |
Estimate your own monthly cost
Cost = input price × input volume + output price × output volume. The same five workloads run on every model page, so any two compare directly.
Mercury 2 vs alternatives
| Model | Input / 1M | Output / 1M | Context | Our test |
|---|---|---|---|---|
| Mercury 2 | $0.25 | $0.75 | 128K | — |
| Llama 3.3 Euryale 70B | $0.65 | $0.75 | 131K | — |
| MiniMax M2.7 | $0.18 | $0.72 | 205K | — |
| Qwen-Plus | $0.26 | $0.78 | 1M | — |
When not to use Mercury 2
- It is served by a single provider, so there is less failover headroom during an outage.
Specs
| Model ID | inception/mercury-2 |
| Modality | text->text (input: text) |
| Context window | 128,000 tokens |
| Max output | 50,000 tokens |
| Tool / function calling | ✅ Yes |
| Structured output (JSON) | ✅ Yes |
| Released | 2026-03-04 |
| Open weights | — (hosted API only) |
How to call Mercury 2
from openai import OpenAI
client = OpenAI(base_url="https://api.datallmlab.com/v1", api_key="YOUR_DATALLM_LAB_KEY")
resp = client.chat.completions.create(
model="inception/mercury-2",
messages=[{"role": "user", "content": "Hello"}],
# supports tools=[...] and tool_choice
)
print(resp.choices[0].message.content)curl https://api.datallmlab.com/v1/chat/completions \
-H "Authorization: Bearer YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"inception/mercury-2","messages":[{"role":"user","content":"Hello"}]}'import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://api.datallmlab.com/v1", apiKey: process.env.DATALLM_KEY });
const r = await client.chat.completions.create({
model: "inception/mercury-2",
messages: [{ role: "user", content: "Hello" }],
});
console.log(r.choices[0].message.content);The same key routes Mercury 2 and 300+ other models — switch models by changing one string. How OpenAI-compatible APIs work.
Prompting tips for Mercury 2
- State the goal, not every step. Mercury 2 reasons internally — give it the objective, constraints and success criteria and let it plan the approach; over-scripting each step tends to lower quality. Turn effort up for hard problems.
- Give it real tools. Pass a
tools=[...]schema instead of asking it to "pretend" — let Mercury 2 emit tool calls, execute them, and feed results back for the next turn. - Constrain JSON with a schema. Use
response_format/ structured outputs rather than "reply in JSON" to get valid, parseable objects every time. - Cheap enough to batch. Great for high-volume classification, extraction and drafting — template the prompt, batch requests, and validate outputs programmatically.
Tips are derived from Mercury 2's actual capabilities — context window, tool & JSON support, modality and price tier — not generic advice.
Open-source tools for Mercury 2
Popular open-source frameworks and agents to build with Mercury 2 over the API — star counts pulled from GitHub (July 2026).
Listed by GitHub stars; inclusion is by ecosystem relevance (agent frameworks, SDKs and gateways), not affiliation. Stars change — see each repo for current numbers.
Migrating to Mercury 2
Coming from OpenAI or another gateway? On an OpenAI-compatible setup the only changes are base_url → https://api.datallmlab.com/v1 and model → inception/mercury-2. Messages, streaming, tool calls and the rest of your code stay the same. Routing & failover guide.
Rate limits & reliability
Rate limits here are the DataLLM Lab gateway's, not the upstream vendor's. On 429 (rate limited) or 503 (provider busy), retry with exponential backoff. See the error-code guide and failover setup.
Related reading
Call Mercury 2 with one key
300+ models behind one OpenAI-compatible endpoint — better prices, better uptime, no subscriptions.
Get an API keyCompare pricingFrequently asked questions
What is Mercury 2?
Mercury 2 is an extremely fast reasoning LLM, and the first reasoning diffusion LLM (dLLM). It accepts text input with a 128K-token context window and was released on 2026-03-04. On DataLLM Lab it is callable through one OpenAI-compatible endpoint.
How much does Mercury 2 cost?
On DataLLM Lab it is $0.25 per 1M input tokens and $0.75 per 1M output tokens, with cached input at $0.02/1M — cheaper than about 69% of the 309-model catalog on output price. Pay-as-you-go, no subscription.
What is the context window of Mercury 2?
128K tokens, with up to 50K max output tokens.
Is Mercury 2 open source?
No open weights are published — it is available through hosted API access only.
How do I call the Mercury 2 API?
Point any OpenAI SDK at https://api.datallmlab.com/v1 and set model to "inception/mercury-2". One DataLLM Lab key routes this model and 300+ others; no code changes beyond the base URL and model string.
What are good alternatives to Mercury 2?
Close options by price and capability include Llama 3.3 Euryale 70B, MiniMax M2.7, Qwen-Plus — all callable with the same DataLLM Lab key.