leanstral-1-5
Mistral AI/Proprietary/1 provider
Leanstral 1.5 is an updated Lean 4 formal proof engineering model from Mistral AI, optimized for automated theorem proving and autoformalization. It has 119B total parameters with 6.5B active and supports a 256K token context window. It supports native function calling and structured output.MoreLess
Which id to call
leanstral-1-5Requesty routes this id across every provider serving leanstral-1-5, picking on price and health and failing over automatically. The id stays valid when a provider changes underneath it.
From /1M input
free
Mistral AI SAS
Context
262K
33K output
Best first token
1.54s
Mistral AI SAS
Regions
1
chat
Capabilities 2/8
202/s↑ 59/s
Week of Aug 17, latest, median of 1 provider
Median tokens per second once generation starts, measured on traffic routed through Requesty through Oct 3. Hover a week to read it.moreless
Each provider line is that provider's own median across every model it serves, which is the grain published per provider, so a provider line can cover weeks this model was not called in yet. The exact per-provider figures for this model are ranked below.
1 endpoint / 1 region
Providers serving leanstral-1-5
Provider prices, per 1M tokens. Pay as you go adds 5%, or 0% on your own keys.moreless
The pane ranks the regions on how leanstral-1-5 performed for requests coming from each one, where the share is how much of that region's traffic this model carries. Whole-window figures, because that is the grain Requesty publishes per provider and per region.
By traffic region
Median wait before the first token arrives. Bar length is the value, so the shortest bar wins.moreless
Whole-window figures as published, not an average of weekly points. Measured over streaming responses only, because a non streaming request has no first token event. A reasoning model thinks before it emits anything, so compare its wait against its reasoning share rather than against a non reasoning model.
| Rank | Cost 10wk | Privacy | |||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | Mistral AI SAS | EU | 262K | free | free | free | 1.54s | zdr |
A column is blank where no qualifying sample exists, and every row links to that provider's endpoint page.
model=
Which id to call
One base url, https://router.requesty.ai/v1, and one key for every id here.
leanstral-1-5Requesty routes this id across every provider serving leanstral-1-5, picking on price and health and failing over automatically. The id stays valid when a provider changes underneath it.
OpenAI compatible
Call it in three lines
Change the base url, use your Requesty key, set the model to any id on the left. Existing OpenAI SDK code needs no other edit.
123456789101112131415from openai import OpenAI client = OpenAI( api_key="YOUR_REQUESTY_API_KEY", base_url="https://router.requesty.ai/v1", ) response = client.chat.completions.create( model="leanstral-1-5", messages=[ {"role": "user", "content": "Explain quantum computing in one paragraph."}, ], ) print(response.choices[0].message.content)
Artificial Analysis
Benchmark scores
Graduate-level physics, chemistry & biology questions designed to resist Googling.
Artificial Analysis Intelligence Index: a composite of multiple evaluations measuring overall model capability.
Scores from artificialanalysis.ai. They measure the model, not the provider, so they are the same on every endpoint above.
6
More from Mistral AI
Reference
leanstral-1-5 questions
Which providers serve leanstral-1-5?
leanstral-1-5 is available from 1 provider through Requesty: Mistral AI SAS. All endpoints share one OpenAI-compatible API and one key, and Requesty fails over between them automatically.
How much does leanstral-1-5 cost?
Pricing starts at free per million input tokens and free per million output tokens on Mistral AI SAS, the cheapest endpoint. Prices vary by provider and region; the table above shows every endpoint. Those are the upstream provider rates: pay as you go adds 5% on top, or 0% if you bring your own provider keys.
Is leanstral-1-5 open weights?
No. leanstral-1-5 is a proprietary model from Mistral AI, served through Mistral AI's own API and licensed cloud platforms.
What is the context window of leanstral-1-5?
leanstral-1-5 supports up to 262K tokens of context, with up to 33K output tokens per response. Some providers expose a smaller window; check the per-endpoint context column above.
How do I use leanstral-1-5 with the OpenAI SDK?
Install the OpenAI SDK, set base_url to "https://router.requesty.ai/v1", set your API key to your Requesty key, and set the model to "leanstral-1-5" or any endpoint id from the table above. The quickstart section shows Python, JavaScript and cURL snippets.
Should I call leanstral-1-5 by its managed id or a provider id?
Use the managed id, "leanstral-1-5". Requesty picks which of the 1 provider serves each request based on price and health, and fails over when one degrades, so the id keeps working while the routing changes underneath it. There is also an EU-only id, "leanstral-1-5@eu", which routes the same way but only through EU-hosted providers. Send a provider id like "mistral/leanstral-1-5" only when you need one specific deployment and want no failover.
Route leanstral-1-5 through one endpoint
One key for 1 provider on this model and 600+ others. No markup on provider prices, automatic failover, caching built in.