GPT-6 Sol — strong reasoning for coding and agent work
GPT-6 Sol is built for complex coding and agentic workflows, with a 1.05M-token context. $1.60 / 1M input, $8.00 / 1M output per 1M tokens.
- Reasoning effort control
- 1.05M-token context
- Image input
- Prompt caching
- Streaming
Try GPT-6 Sol
Chat with GPT-6 Sol, attach images, and see the tokens and cost of every answer.
gpt-6-sol$1.60 in · $8.00 out per 1M tokens
Temperature and Top P work only with reasoning effort none.
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 Sol output
One prompt, sent to GPT-6 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 lets one thread access a shared resource at a time. The thread that locks it must unlock it. Use a mutex to protect shared data or a critical section from simultaneous access. A **semaphore** is a counter that controls how many threads can proceed. Use one to limit access to a pool of resources, such as a fixed number of database connections, or to signal that work is ready.
Generated 2026-09-28. Answers vary from run to run.
GPT-6 Sol pricing
GPT-6 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 | $0.16 / 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 | $0.32 / 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 Sol?
GPT-6 Sol is OpenAI's GPT-6 model for complex coding and agentic workflows. It sits between GPT-6 Astra, the most capable model, and GPT-6 Luna, the most efficient one. GPT-6 Sol reads up to 1.05M tokens of context and writes up to 128K tokens per request.
GPT-6 Sol lets you choose how hard it thinks: reasoning effort runs from none to max, and the default is medium. At none it answers without reasoning and accepts temperature and top_p, which suits fast, simple steps.
Model ID: gpt-6-sol · Input: text, images · Output: text · Formats: OpenAI Responses, OpenAI Chat Completions, Anthropic Messages.
Two ways to use GPT-6 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 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-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 Sol is good at
GPT-6 Sol is made for work you repeat every day: building features, reviewing code and analysing data.
Everyday coding
GPT-6 Sol writes, reviews and debugs code across a real codebase.
Agent workflows
A 1.05M-token context lets an agent run many steps without losing the thread.
Data analysis
Hand GPT-6 Sol tables, logs or reports and get a clear read on them.
Images in the prompt
GPT-6 Sol reads screenshots and charts alongside your text.
Effort you control
None for quick answers, max for hard problems. Pay for the reasoning you ask for.
Cheaper repeat context
Cached input on GPT-6 Sol costs 10% of the input rate.
What teams build with GPT-6 Sol
Code review bots
Run GPT-6 Sol on every pull request and post findings back.
Support assistants
Answer from your docs with the whole knowledge base in context.
Structured extraction
Turn tickets and invoices into JSON with a text.format schema.
Start using GPT-6 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 Sol
Send gpt-6-sol as the model. Set reasoning effort to trade depth for speed and cost.
- 04
Check the bill
Every request shows its tokens and charge in your usage records.
GPT-6 Sol on SeedRouter at a glance
What you can use today.
| Feature | GPT-6 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 | Yes |
| Failed requests | Not charged |
Batch, Flex, background mode and service tiers are not offered.
GPT-6 Sol limits
1.05M-token context
On GPT-6 Sol, prompt, images and history share one 1.05M-token window; input is capped at 922K.
128K tokens out
One GPT-6 Sol request can return up to 128K tokens, reasoning included.
Long prompts cost more
Above 272K input tokens, the whole GPT-6 Sol request is billed at the higher long-context rates.
Sampling needs effort none
GPT-6 Sol accepts temperature and top_p only when reasoning effort is none.
Why call GPT-6 Sol through SeedRouter
One key, three formats
Call GPT-6 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 a lower GPT-6 Sol rate.
Image input
Send screenshots, charts and photos by URL with your prompt.
Streaming
Stream GPT-6 Sol tokens as they arrive with stream: true.
Related models
Other models you can call with the same key.
Call GPT-6 Astra with the OpenAI SDK. OpenAI's most capable model, with a 1.05M-token context, live per-token pricing and a playground you can try right now.
View pricingCall GPT-6 Luna with the OpenAI SDK. The lowest-cost GPT-6 model, with a 1.05M-token context, live per-token pricing and a playground you can try right now.
View pricingGPT-6 Sol guides
Walkthroughs and comparisons for this model.
How to access the GPT-6 API: get a key, call GPT-6 Astra, Sol or Luna with the OpenAI SDK, set reasoning effort, stream, send images and avoid common errors.
GPT-6 API pricing for Astra, Sol and Luna per million tokens: input, output, cached input, cache writes and the 272K long-context rate, with worked examples.
GPT-6 Astra vs Sol vs Luna compared: specs, prices, OpenAI benchmark results, reasoning effort and a clear pick for coding, agents and high-volume work.
GPT-6 Astra, Sol and Luna vs Claude Opus 5.5: specs, token prices, the benchmark results both labs published, and which model fits coding, agents and cost.
GPT-6 vs GPT-5.6 compared: Sol and Luna at half the price, the same 1.05M context, newer knowledge, OpenAI benchmark gains and what to change when you migrate.
GPT-6 Sol FAQ
What is GPT-6 Sol?+
GPT-6 Sol is OpenAI's GPT-6 model for complex coding and agentic workflows. It has a 1.05M-token context window, writes up to 128K tokens per request and lets you set reasoning effort from none to max.
Should I use GPT-6 Sol, GPT-6 Astra or GPT-6 Luna?+
Use GPT-6 Astra for the hardest end-to-end work, GPT-6 Sol for demanding coding and agent tasks at a lower price, and GPT-6 Luna for focused, high-volume jobs where cost matters most.
How much does GPT-6 Sol cost?+
GPT-6 Sol is billed at $1.60 / 1M input and $8.00 / 1M output per 1M tokens. Cached input costs 10% of the input rate. Prompts above 272K tokens use the long-context rates shown in the pricing table.
What is the default reasoning effort of GPT-6 Sol?+
GPT-6 Sol defaults to medium. You can set none, low, medium, high, xhigh or max; none turns reasoning off and is the only level that accepts temperature and top_p.
What is the knowledge cutoff of GPT-6 Sol?+
GPT-6 Sol has a knowledge cutoff of April 20, 2026. For newer facts, pass them in the prompt.
What is the GPT-6 Sol model ID and how do I call it?+
The model ID is gpt-6-sol. Create a SeedRouter API key, point the OpenAI SDK at https://api.seedrouter.ai/v1 and send gpt-6-sol as the model with the Responses or Chat Completions API.
Can GPT-6 Sol read images?+
Yes. GPT-6 Sol accepts images alongside text, sent by URL in the request. It returns text only.
Am I charged if a GPT-6 Sol request fails?+
No. A GPT-6 Sol request that returns an error is not charged. You pay only for the tokens a finished request reports.
Try GPT-6 Sol now
Send your first GPT-6 Sol request from the playground or your own code in minutes.