GPT-6.1 Sol — near-Astra coding and agent work for less
GPT-6.1 Sol is the upgraded GPT-6 Sol: close to GPT-6 Astra on coding, computer use and professional work, with a 1.05M-token context. $1.60 / 1M input, $8.00 / 1M output.
- Near-Astra performance
- 1.05M-token context
- Image input
- 95% off cached input
- Streaming
Try GPT-6.1 Sol
Chat with GPT-6.1 Sol, attach screenshots, and see the tokens and cost of every answer.
gpt-6.1-sol$1.60 in · $8.00 out per 1M tokens
GPT-6.1 Sol does not use temperature or Top P at any reasoning effort.
Try one of these prompts
Messages are billed from your balance at the rates below, like an API call. Failed requests are free.
Real GPT-6.1 Sol output
One prompt, sent to GPT-6.1 Sol at low reasoning effort. Unedited.
Explain the difference between a mutex and a semaphore in two short paragraphs, and say when to use each.
A mutex is a lock that allows only one thread at a time to access a shared resource. It has ownership: the thread that locks it must unlock it. Use a mutex to protect shared data or a critical section, such as updating a shared counter. A semaphore maintains a count of available permits. Threads acquire permits before proceeding and release them afterward; unlike a mutex, it generally has no ownership requirement. Use a semaphore to limit concurrent access to a pool of resources, such as allowing up to five simultaneous database connections, or to signal between threads.
Generated 2026-10-05. Answers vary from run to run.
GPT-6.1 Sol pricing
GPT-6.1 Sol is billed per token from your balance. Rates below are live, the same ones your account is charged.
Example sizes are for illustration. Your bill follows the tokens each request reports.
| Item | Counted as | Rate | Billing |
|---|---|---|---|
| Input | Prompt tokens not read from or written to the cache | $1.60 / 1M | Per 1M tokens |
| Output | Answer and reasoning tokens | $8.00 / 1M | Per 1M tokens |
| Cached input | Prompt tokens served from the prompt cache | $0.08 / 1M | Per 1M tokens |
| Cache write | Prompt tokens written to the prompt cache | $2.00 / 1M | Per 1M tokens |
| Input, over 272K | Input when the prompt exceeds 272K tokens | $3.20 / 1M | Per 1M tokens |
| Output, over 272K | Output when the prompt exceeds 272K tokens | $12.00 / 1M | Per 1M tokens |
| Cached input, over 272K | Cache reads when the prompt exceeds 272K tokens | $0.16 / 1M | Per 1M tokens |
| Cache write, over 272K | Cache writes when the prompt exceeds 272K tokens | $4.00 / 1M | Per 1M tokens |
| Failed request | Any request that returns an error | Free | Not charged |
What is GPT-6.1 Sol?
GPT-6.1 Sol is OpenAI's upgrade to GPT-6 Sol for complex coding, computer use and professional work. OpenAI describes it as near-Astra performance at a lower cost: its token rates are one fifth of GPT-6 Astra's. GPT-6.1 Sol reads up to 1.05M tokens of context and writes up to 128K tokens per request.
Reasoning effort runs from low to max, and the default is medium. GPT-6.1 Sol has no none setting, so it always reasons; pick low for quick steps and xhigh or max for long refactors and hard debugging.
Model ID: gpt-6.1-sol · Input: text, images · Output: text · Formats: OpenAI Responses, OpenAI Chat Completions, Anthropic Messages.
Two ways to use GPT-6.1 Sol
Call it from your code, or let your coding agent do it for you.
Call it from your backend
Point the official OpenAI SDK at SeedRouter and keep your code. GPT-6.1 Sol answers both the Responses and Chat Completions formats.
- 1Create an API key
- 2Set the base URL to https://api.seedrouter.ai/v1
- 3Send gpt-6.1-sol as the model
Hand it to your coding agent
Copy a ready prompt. Your agent shows the request and cost before anything is spent.
- 1Copy the prompt
- 2Paste it into your agent
- 3Approve the request
What GPT-6.1 Sol is good at
GPT-6.1 Sol takes on the long jobs: multi-file refactors, deep codebase investigations and agents that run for many steps.
Complex refactors
GPT-6.1 Sol plans, edits and tests changes across a whole codebase.
Long-running agents
A 1.05M-token context keeps a multi-step agent on track from start to finish.
Computer use
GPT-6.1 Sol reads real interfaces from screenshots, so agents can work through app steps.
Images in the prompt
Pass screenshots, charts and diagrams with your text.
Effort you control
Low for quick steps, max for the hardest problems. Pay for the reasoning you ask for.
95% off repeat context
Cached input on GPT-6.1 Sol costs 5% of the input rate.
What teams build with GPT-6.1 Sol
Coding agents
Give GPT-6.1 Sol a ticket and let it plan, edit and test the change.
Codebase Q&A
Load a large repository into context and ask where things break and why.
Structured extraction
Turn tickets, contracts and invoices into JSON with a text.format schema.
Start using GPT-6.1 Sol in four steps
- 01
Create a key
Sign in and create an API key. Add credit whenever you need it; there is no subscription.
- 02
Change the base URL
Point the OpenAI SDK at https://api.seedrouter.ai/v1. Your code stays the same.
- 03
Pick GPT-6.1 Sol
Send gpt-6.1-sol as the model. Set reasoning effort from low to max to trade depth for speed and cost.
- 04
Check the bill
Every request shows its tokens and charge in your usage records.
GPT-6.1 Sol on SeedRouter at a glance
What you can use today.
| Feature | GPT-6.1 Sol |
|---|---|
| OpenAI Responses | Yes, official format |
| OpenAI Chat Completions | Yes |
| Anthropic Messages | Yes |
| Image input | Yes, by URL |
| Streaming | Yes |
| Prompt caching | Yes, cached input and cache writes billed apart |
| Reasoning effort none | No, low is the lightest setting |
| Failed requests | Not charged |
Batch, Flex, background mode and service tiers are not offered.
GPT-6.1 Sol limits
1.05M-token context
On GPT-6.1 Sol, prompt, images and history share one 1.05M-token window; input is capped at 922K.
128K tokens out
One GPT-6.1 Sol request can return up to 128K tokens, reasoning included.
Long prompts cost more
Above 272K input tokens, the whole GPT-6.1 Sol request is billed at the higher long-context rates.
No sampling controls
GPT-6.1 Sol does not use temperature or top_p at any reasoning effort.
Why call GPT-6.1 Sol through SeedRouter
One key, three formats
Call GPT-6.1 Sol with OpenAI Responses, Chat Completions or Anthropic Messages, using the same key.
Pay per token
Top up once and spend it on any model. No plan, no monthly fee.
Failures are free
A request that errors is not charged.
Live prices
The rates on this page are the rates your account pays.
Prompt caching
Repeated prompt prefixes are read from the cache at 5% of the GPT-6.1 Sol input rate.
Image input
Send screenshots, charts and photos by URL with your prompt.
Streaming
Stream GPT-6.1 Sol tokens as they arrive with stream: true.
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View pricingGPT-6.1 Sol guides
Walkthroughs and comparisons for this model.
GPT-6.1 Sol pricing explained: input, cached input, cache write and output rates, the 272K long-context rule, worked request costs and how to spend less.
Which GPT-6.1 Sol reasoning effort to use: real timings, token counts and costs at low, medium, high, xhigh and max, why it feels slow, and where to start.
GPT-6.1 Sol vs Claude Opus 5.5 and Claude Sonnet 5.5: specs, list prices, the benchmarks OpenAI published against Opus 5.5 and which model fits your work.
GPT-6.1 Sol vs GPT-6 Astra and GPT-6 Sol: specs, prices, the benchmark gaps OpenAI published, what changed from GPT-6 Sol and which model to use.
GPT-6.1 Sol FAQ
What is GPT-6.1 Sol?+
GPT-6.1 Sol is OpenAI's upgraded GPT-6 Sol for complex coding, computer use and professional work, with performance close to GPT-6 Astra. It has a 1.05M-token context window and writes up to 128K tokens per request.
Should I use GPT-6.1 Sol, GPT-6 Sol or GPT-6 Astra?+
GPT-6.1 Sol is the upgrade to GPT-6 Sol and comes close to GPT-6 Astra at one fifth of Astra's token rates. Keep GPT-6 Sol if you need reasoning effort none with temperature, and use GPT-6 Astra for the hardest end-to-end work.
How much does GPT-6.1 Sol cost?+
GPT-6.1 Sol is billed at $1.60 / 1M input and $8.00 / 1M output per 1M tokens. Cached input costs 5% of the input rate. Prompts above 272K tokens use the long-context rates shown in the pricing table.
What reasoning efforts does GPT-6.1 Sol support?+
GPT-6.1 Sol supports low, medium, high, xhigh and max, and defaults to medium. It does not support none or minimal, so it always reasons and does not use temperature or top_p.
What is the knowledge cutoff of GPT-6.1 Sol?+
GPT-6.1 Sol has a knowledge cutoff of April 30, 2026. For newer facts, pass them in the prompt.
What is the GPT-6.1 Sol model ID and how do I call it?+
The model ID is gpt-6.1-sol. Create a SeedRouter API key, point the OpenAI SDK at https://api.seedrouter.ai/v1 and send gpt-6.1-sol as the model with the Responses or Chat Completions API.
Can GPT-6.1 Sol read images?+
Yes. GPT-6.1 Sol accepts images alongside text, sent by URL in the request. It returns text only.
Am I charged if a GPT-6.1 Sol request fails?+
No. A GPT-6.1 Sol request that returns an error is not charged. You pay only for the tokens a finished request reports.
Try GPT-6.1 Sol now
Send your first GPT-6.1 Sol request from the playground or your own code in minutes.