GPT-6.1 Sol API launch: pricing and usage

GPT-6.1 Sol is OpenAI’s newer Sol model, positioned as near-Astra performance for complex coding and professional work at a lower cost. On LaoZhang API it has the same input and output prices as gpt-6-sol, and half the cache-read price.

Published: October 13, 2026
Last verified: October 13, 2026
Status: Active; available in the default token group

Key facts

Item	Details
Model ID	`gpt-6.1-sol` (Chat Completions returns the snapshot `gpt-6.1-sol-2026-09-29`)
OpenAI release date	September 29, 2026
Available on LaoZhang API	In the public pricing configuration as of October 5, 2026
Endpoints	Base URL `https://api.laozhang.ai/v1`; Chat Completions `POST /v1/chat/completions`, Responses `POST /v1/responses`
Token group and billing	`default` group, usage-based (per token)
Price	$2 input and $10 output per 1M tokens, the same as OpenAI’s Standard rates; long-context rates are in Pricing
Context length (OpenAI)	1,050,000-token context window, with up to 922,000 input tokens and 128,000 output tokens
Tool calling	Requires the Responses API

Pricing

These rates come from LaoZhang API’s public pricing as of October 13, 2026, in US dollars per 1M tokens. They match the Standard rates on OpenAI’s pricing page.

Rate	Standard	Long context
Input	$2	$4
Output	$10	$15
Cache read	$0.1	$0.2
Cache write	$2.5	$5

Requests with up to 272K input tokens use the standard rates. Once a request has more than 272K input tokens, the whole request is billed at the long-context rates. For current rates, see the model and pricing catalog and the console pricing page.

How it differs from GPT-6 Sol

	`gpt-6.1-sol`	`gpt-6-sol`
Input / output (standard)	$2 / $10	$2 / $10
Cache read (standard)	$0.1	$0.2
`reasoning_effort` in Chat Completions	`low`, `medium` (default), `high`, `xhigh`	`none`, `low`, `medium` (default), `high`, `xhigh`, `max`
Function calling in Chat Completions	Not supported; use Responses	Supported when `reasoning_effort` is `none`

Workloads that resend a long prefix, such as long system prompts, multi-turn chats, and agents, pay less overall because cache reads cost half as much.
If your requests use none or minimal, switch to low and compare the results. For max, use the Responses API.
Sampling parameters work only when reasoning effort is none, which GPT-6.1 Sol doesn’t support, so always remove them:
- temperature, top_p
- logprobs, top_logprobs

Call GPT-6.1 Sol

Create an API key in Token management in the default group, with its billing mode set to Usage first (按量优先, recommended) or Usage-based (按量计费). Then export the key in your terminal:

export LAOZHANG_API_KEY="replace-with-your-LaoZhang-API-key"

These examples send one message to gpt-6.1-sol through Chat Completions and through Responses. For Python, run python -m pip install openai first.

Chat Completions
Responses
Python

curl https://api.laozhang.ai/v1/chat/completions \
  -H "Authorization: Bearer $LAOZHANG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6.1-sol",
    "messages": [
      {"role": "user", "content": "Explain a database index in three sentences."}
    ]
  }'

curl https://api.laozhang.ai/v1/responses \
  -H "Authorization: Bearer $LAOZHANG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6.1-sol",
    "input": "Explain a database index in three sentences."
  }'

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["LAOZHANG_API_KEY"],
    base_url="https://api.laozhang.ai/v1",
    timeout=300.0,
    max_retries=0,
)
response = client.responses.create(
    model="gpt-6.1-sol",
    input="Explain a database index in three sentences.",
)
print(response.output_text)

In Chat Completions, the reply text is in choices[0].message.content.
In Responses, the text is in the output item whose type is message; the Python SDK joins it in response.output_text.
Token usage and the charge for each request are in call logs.

Who is affected

Affected: projects that call text models through LaoZhang API’s OpenAI-compatible endpoint. An API key in the default group with the Usage first or Usage-based billing mode can call it.
Not affected: existing models. gpt-6-sol, gpt-6-astra, and gpt-6-luna remain available, and current integrations need no changes.

Frequently asked questions

I already use GPT-6 Sol. Do I need to switch?

No. Both models have the same input and output prices, and GPT-6.1 Sol’s cache reads cost less. If you plan to switch, compare quality, latency, and token usage on representative requests, then adjust reasoning effort and tool calling as described above.

Why does a Chat Completions request with tools return 400?

GPT-6.1 Sol doesn’t support function calling in Chat Completions. Send the request to POST /v1/responses and pass tools in the Responses API format.

Why does `reasoning_effort: "max"` return an error?

In Chat Completions, GPT-6.1 Sol goes up to xhigh. For max, use the Responses API and set reasoning.effort.

How are requests with more than 272K input tokens billed?

The whole request is billed at the long-context rates, not just the tokens above 272K: input and cache rates double, and output rates rise 1.5×, the same rule OpenAI uses.

OpenAI API changelog: the September 29, 2026 entry for GPT-6.1 Sol
GPT-6.1 Sol model page: context window, maximum output, reasoning effort, endpoints, and tools
OpenAI API pricing: standard and long-context rates
GPT-6 Astra, Sol, and Luna launch
Use OpenAI models with LaoZhang API
Model and pricing catalog
Latest announcements

​Key facts

​Pricing

​How it differs from GPT-6 Sol

​Call GPT-6.1 Sol

​Who is affected

​Frequently asked questions

​I already use GPT-6 Sol. Do I need to switch?

​Why does a Chat Completions request with tools return 400?

​Why does reasoning_effort: "max" return an error?

​How are requests with more than 272K input tokens billed?

​Sources and related links