OpenAI's mid-tier GPT-6.1 model in its fastest service tier — near-Astra performance for coding, agents and professional work, with a 1,050K-token context window.
curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "openai-gpt-61-sol-ultrafast",
"messages": [{ "role": "user", "content": "Explain quantum tunneling simply." }]
}'Overview
GPT-6.1 Sol Ultrafast is OpenAI's GPT-6.1 Sol model served in its fastest scheduling tier, live on Venice since October 2026. It delivers near-flagship performance for coding, computer use and professional work, with a 1,050K-token context window, vision input, tool calling, reasoning and web search.
On Venice, GPT-6.1 Sol Ultrafast runs under the anonymized privacy tier: your prompts are not stored, profiled, or used for training, and nothing ties a request to a personal history. You get the same frontier checkpoint OpenAI ships — with vision, function calling, structured output and web search intact — billed per token instead of behind a subscription. Note that Venice's anonymized tier is not end-to-end encrypted or TEE-isolated; the privacy guarantee is zero retention of prompts.
Agent quickstart
The API is OpenAI-compatible: change the base URL and the model id and existing client code works unchanged.
curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "openai-gpt-61-sol-ultrafast",
"stream": true,
"messages": [{ "role": "user", "content": "Draft the release note." }]
}'curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "openai-gpt-61-sol-ultrafast",
"messages": [{ "role": "user", "content": "Find the rate limits." }],
"tools": [{
"type": "function",
"function": {
"name": "search_docs",
"description": "Search the API documentation.",
"parameters": {
"type": "object",
"properties": { "query": { "type": "string" } },
"required": ["query"]
}
}
}],
"tool_choice": "auto"
}'import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["VENICE_API_KEY"],
base_url="https://api.venice.ai/api/v1",
)
resp = client.chat.completions.create(
model="openai-gpt-61-sol-ultrafast",
messages=[{"role": "user", "content": "Build without permission."}],
)
print(resp.choices[0].message.content)Specifications
Assessment
Use cases
Prompting
Set reasoning effort deliberately: use low for drafts and extraction, xhigh or max for hard algorithmic or agentic problems — medium is only the default, not the ceiling.
Structure agent loops so the system prompt and early context stay byte-identical across calls; cached input on Venice costs $0.75 per 1M tokens instead of $15.
Pass multiple images in a single request when comparing screenshots, designs, or documents — the model accepts several image inputs per call.
Demand a JSON schema in the prompt for pipeline work; structured output is a first-class capability, not a prompt hack.
Route anything after April 30, 2026 through the web-search capability instead of trusting parametric memory.
Budget the window: cap prompts around 922K input tokens so you keep room for the full 128K-token output ceiling.
Alternatives
| Model | Best for | Context | Open weights | Price (Venice) |
|---|---|---|---|---|
| GPT-6.1 Sol Ultrafast | Latency-sensitive agentic coding & pro work | 1M tokens | No | $15 in · $75 out / 1M |
| Claude Opus 5 | Frontier reasoning & long documents | 1M tokens | No | $6 in · $30 out / 1M |
| Gemini 3.8 Flash | Fast everyday work at low cost | 1M tokens | No | $0.94 in · $4.69 out / 1M |
| Kimi K3 | Open-weight frontier alternative | 1M tokens | Yes | $3.75 in · $18.75 out / 1M |
GPT-6.1 Sol Ultrafast is the right pick when a human is actively waiting on the answer — interactive coding agents and live professional workflows — and the per-token premium is cheaper than the latency. For batch jobs, overnight sweeps, or budget-sensitive volume, Claude Opus 5 or Gemini 3.8 Flash are the better buys.
Pricing
Billed per token on Venice: $15 per 1M input tokens and $75 per 1M output tokens.
New Venice accounts include a free daily allowance and 500 welcome credits — no credit card required.
Getting a key
Create a key in API settings. Nothing else is required to start.
Export it as VENICE_API_KEY so the snippets above run unedited.
Point an existing OpenAI client at https://api.venice.ai/api/v1. The scheme is part of the value: an OpenAI client given a bare host does not resolve it.
Pass openai-gpt-61-sol-ultrafast as the model and send the request.
FAQ
GPT-6.1 Sol Ultrafast is OpenAI's GPT-6.1 Sol model — the mid-tier model in the GPT-6 family, released September 29, 2026 — served through its fastest scheduling tier. The checkpoint, 1,050K-token context window, and answers are identical to standard GPT-6.1 Sol; only the response speed and the price differ. It is aimed at coding, computer use, and professional work.
On Venice, GPT-6.1 Sol Ultrafast is billed per token at $15 per 1M input tokens and $75 per 1M output tokens, with cached input at $0.75 per 1M. There is no subscription required — you pay only for what you use, and repeated context in agent loops qualifies for the cached rate.
Neither. GPT-6.1 Sol Ultrafast is a proprietary OpenAI model with closed weights, so it cannot be self-hosted or fine-tuned. It is not free to run — Venice bills per token — though Venice offers free daily credits for new accounts to try it. If you need open weights, Kimi K3 on Venice is the closest frontier-class open alternative.
Choose GPT-6.1 Sol Ultrafast when response speed is the binding constraint: interactive coding sessions and user-facing agents. Choose Claude Opus 5 when you can wait — it costs less than half as much per token on Venice, matches the 1M-class context window, and is a strong default for deep reasoning and long-document work.
Yes. On Venice, GPT-6.1 Sol Ultrafast supports tool use / function calling, vision with multiple image inputs per request, structured JSON-schema output, reasoning with a selectable effort level from low to max, and web search. Audio and video modalities are not supported — input is text and images, output is text.
Third-party testing shortly after launch measured Ultrafast completing the same coding jobs roughly four times faster than the Standard tier with identical answer quality, at about six times the token cost. OpenAI community reports cite up to 8x speed. The exact multiplier depends on the workload, but the trade is consistent: wall-clock time bought with tokens.
There is no separate model. Ultrafast is a service tier over the same gpt-6.1-sol checkpoint — same 1,050K-token context, same 128K output ceiling, same April 30, 2026 knowledge cutoff, same answers. Upstream it is selected with a service_tier setting; on Venice it is offered as its own faster, more expensive listing.
Venice runs GPT-6.1 Sol Ultrafast under its anonymized privacy tier: prompts are not stored, profiled, or used for training, and requests carry no personal history. You can use it in the Venice app or through the Venice API. Note that this tier is not end-to-end encrypted or TEE-isolated — the guarantee is zero retention of your prompts.
The underlying GPT-6.1 Sol model was released by OpenAI on September 29, 2026, and the Ultrafast service tier was added on October 8, 2026 — the same day Venice listed it. Both are live and available now.
One key, free to start, no credit card.