GPT-6.1 Sol: Model ID, Responses API Quick Start, and Migration Checks

The official API model ID for GPT-6.1 Sol is gpt-6.1-sol—with a dot between 6 and 1. To start, set that value in the model field of a Responses API request. For tool calling, use Responses; OpenAI documents Chat Completions support for this model only for requests without tools.

Keep official model specifications separate from gateway access. An OpenAI model listing does not establish that the same model is included in an llmapi.pro subscription or available through your selected billing channel.

Use the exact official model ID

The OpenAI model catalog lists GPT-6.1 Sol with the request ID gpt-6.1-sol. Do not substitute gpt-6-1-sol in an official API request.

OpenAI positions Sol as an option for balancing intelligence and cost. Its GPT-6 guide recommends comparing Sol with Astra on your own tasks to assess the quality-versus-cost tradeoff. Use the official catalog for current specifications and pricing rather than assuming a particular cost saving for your workload.

If you currently use gpt-6-sol, review the migration guidance before switching. In particular, check reasoning settings and tool usage rather than treating this as only a model-name replacement.

Start with a simple Responses API request

The following Python example adapts the request structure in OpenAI's text generation guide, replacing its Astra model value with the documented Sol ID. It is an official-API starter example, not a demonstration of a successful llmapi.pro call. Use it with your configured OpenAI SDK client credentials.

from openai import OpenAI

client = OpenAI()

response = client.responses.create(
    model="gpt-6.1-sol",
    input="Write a one-sentence bedtime story about a unicorn.",
)

print(response.output_text)

For a direct HTTP request, the same documented request pattern is:

curl "https://api.openai.com/v1/responses" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "gpt-6.1-sol",
    "input": "Write a one-sentence bedtime story about a unicorn."
  }'

Replace YOUR_API_KEY with your own credential when running the request; do not publish it. The prompt is a simple illustrative input, not a benchmark or a claim about the model's response.

For Python, the documented output_text convenience property aggregates text outputs. If you process the raw HTTP response instead, inspect the output items rather than assuming the answer is always at output[0].content[0].text. OpenAI notes that the output array can also contain tool calls, reasoning-related data, and other items.

Check reasoning effort and tools before switching

GPT-6.1 Sol supports these reasoning.effort values:

• low
• medium — the documented default
• high
• xhigh
• max

It does not support none or minimal. OpenAI specifically distinguishes the older GPT-6 Sol, which supports none, from GPT-6.1 Sol, which does not. Inspect any inherited request settings before changing the model ID.

The protocol check is equally important:

For an initial migration test, keep the input simple and review the returned text. Then evaluate representative application tasks with your intended reasoning setting and tool workflow. Do not assume that prompting advice based on Astra's behavior describes Sol identically: OpenAI advises evaluating those prompts with the chosen model and workload.

Verify llmapi.pro model access and billing separately

For llmapi.pro, start with the model selection documentation and client configuration documentation. They treat the model ID, protocol compatibility, and billing mode as separate settings.

Before redirecting a client, check each of the following:

1. Exact request ID: Copy the ID from the applicable subscription list or pay-as-you-go channel catalog. Do not infer a request ID from a display name.
2. Billing mode and key: Monthly subscriptions use a subscription key and shared plan quota. Pay-as-you-go API billing uses a separate key and balance.
3. Protocol support: Confirm that the selected model and channel support the protocol your client needs, particularly Responses tool calling. OpenAI-compatible client support alone does not establish subscription coverage.
4. Base URL: The llmapi.pro setup documentation lists https://llmapi.pro/v1 for OpenAI-protocol clients. Treat this as a client configuration value, not proof of GPT-6.1 Sol availability.
5. Subscription eligibility: Check the subscription model list and plans. The documented authoritative subscription model list is returned by GET /v1/models.

Do not treat a listing for gpt-6-sol as a listing for gpt-6.1-sol. Confirm the exact new ID under the billing mode you intend to use before switching. Likewise, topping up API credit does not increase subscription quota.

A focused pre-switch checklist

Before replacing an existing Sol configuration, verify:

• The official API request uses gpt-6.1-sol, including the dot.
• Any explicit reasoning effort is supported; remove or replace inherited none or minimal settings.
• Tool-based requests use Responses rather than Chat Completions.
• Response handling accommodates multiple output items or uses the SDK's text aggregation helper.
• Your destination, matching credential, exact model ID, and billing mode have been checked together.
• Your own task evaluation supports the switch; model positioning is not a measured result for your application.

Start with the small text request above for the official API. For llmapi.pro, resolve exact-model eligibility and protocol support first, then configure the client using the site's documentation.