GPT-5.1-Codex with Jev
GPT-5.1-Codex is a model from OpenAI, released 2025-11-13. It costs $1.25 per million input tokens and $10 per million output tokens, reads up to 400K tokens of context, and writes up to 128,000 tokens in one reply. Through llm11, set model to openai/gpt-5.1-codex.
- Input price
- $1.25 / 1M
- Output price
- $10 / 1M
- Context window
- 400K tokens
- Max output
- 128K tokens
- Cached input
- $0.130 / 1M
- Released
- 2025-11-13
- Accepts
- text, image
Read from the provider's prompt cache
Read from the live catalogue and refreshed daily. At blended list price, 19% of the 332 priced models we can call cost more.
Using GPT-5.1-Codex with Jev
Jev is TypeSafe AI's System One model. It reads each request first and decides which model in your pool answers, with a calibrated confidence on that call. GPT-5.1-Codex does the answering when Jev sends it work, or when you name it yourself. GPT-5.1-Codex falls in the llm11-balanced band, and the labs and limits it meets make it eligible for that pack. Packs keep a spread of eight models per band, and it is not one of the eight today, so it is only picked when you name it in a custom pool.
Jev is new, so we have not published results for GPT-5.1-Codex with and without it, and this page does not invent any. Every response comes with a receipt that names the model that answered and what it cost against your most expensive model, so you can measure the pairing on your own traffic.
What a request costs
List price arithmetic, the same sum a receipt does. llm11 adds nothing per request; the only fee is on buying credits.
| Request | Tokens in / out | One | A thousand |
|---|---|---|---|
| Short chat turn | 500 / 200 | $0.00263 | $2.63 |
| Question over retrieved documents | 4,000 / 500 | $0.010 | $10.00 |
| Long document summary | 30,000 / 1,000 | $0.048 | $47.50 |
Cheaper models to try
The catalogue has no benchmark score for GPT-5.1-Codex, so this is a price ordering. It does not claim these answer as well.
| Model | Input / 1M | Output / 1M | Context | Released |
|---|---|---|---|---|
| Google Gemini 3.5 Flash | $1.50 | $9.00 | 1.05M | |
| SpaceXAI Grok 4.7 | $2.00 | $6.00 | 500K | |
| Qwen Qwen3.8 Max (0902) | $2.00 | $6.00 | 1M | |
| Qwen Qwen3.8 2.4T A95B | $2.00 | $6.00 | 1.05M |
Call it
Same OpenAI request shape. Naming the model pins it, so nothing is routed, and the answer is still checked.
python
from openai import OpenAI
client = OpenAI(base_url="https://www.llm11.com/v1", api_key="llm11_live_...")
res = client.chat.completions.create(
model="openai/gpt-5.1-codex",
messages=[{"role": "user", "content": "Hello"}],
)More from OpenAI
| Model | Input / 1M | Output / 1M | Context | Released |
|---|---|---|---|---|
| GPT-6 Luna | $0.100 | $0.500 | 1.05M | |
| GPT-6 Luna Pro | $0.100 | $0.500 | 1.05M | |
| GPT-6 Sol | $2.00 | $10 | 1.05M | |
| GPT-6 Sol Pro | $2.00 | $10 | 1.05M | |
| GPT-6 Astra | $10 | $50 | 1.05M | |
| GPT-6 Astra Pro | $10 | $50 | 1.05M |
Questions
- What is GPT-5.1-Codex with Jev?
- Jev is TypeSafe AI's System One model. It reads each request first and decides which model in your pool answers, with a calibrated confidence on that call. GPT-5.1-Codex does the answering when Jev sends it work, or when you name it yourself. GPT-5.1-Codex falls in the llm11-balanced band, and the labs and limits it meets make it eligible for that pack. Packs keep a spread of eight models per band, and it is not one of the eight today, so it is only picked when you name it in a custom pool. Routing decisions are made by Jev, TypeSafe AI's System One model.
- Is GPT-5.1-Codex a System One model?
- No. GPT-5.1-Codex answers requests. The System One model is Jev, which decides which model answers each one, so the two do different jobs and llm11 uses both.
- How much does GPT-5.1-Codex cost?
- $1.25 per million input tokens and $10 per million output tokens. A 4,000 token prompt with a 500 token answer costs about $0.010, so a thousand of them is about $10.00. llm11 passes provider list price through and charges 5% when you buy credits.
- What is the GPT-5.1-Codex context window?
- 400,000 tokens, with up to 128,000 tokens in a single reply.
- Does GPT-5.1-Codex support tool calling and structured output?
- The catalogue lists tool calling, structured output and reasoning controls.
- Can I use GPT-5.1-Codex through llm11?
- Yes. Set model to openai/gpt-5.1-codex on the OpenAI-compatible endpoint and the request goes to it directly, with verification still running.
- Does Jev route to GPT-5.1-Codex?
- Routing decisions are made by Jev, TypeSafe AI's System One model. GPT-5.1-Codex falls in the llm11-balanced band, and the labs and limits it meets make it eligible for that pack. Packs keep a spread of eight models per band, and it is not one of the eight today, so it is only picked when you name it in a custom pool.
- What is a cheaper alternative to GPT-5.1-Codex?
- Nearest in price and below it: Google Gemini 3.5 Flash at $1.50 in and $9.00 out, SpaceXAI Grok 4.7 at $2.00 in and $6.00 out and Qwen Qwen3.8 Max (0902) at $2.00 in and $6.00 out. The catalogue has no benchmark score for GPT-5.1-Codex, so this is a price ordering. It does not claim these answer as well.