GPT-6 Sol API
NewLLMThe GPT-6 Sol API is OpenAI's frontier GPT-6 reasoning route, with 1M context, image input, and tool use.
- Input · USD / 1M tokens$0.225 USDOfficial price
$2 USD - Output · USD / 1M tokens$1.35 USDOfficial price
$10 USD - Savings91%
- Context1M
- View tool pricing and billing rules
What are we making today?
Bring an idea, a question, or a first draft.
01
What this model is for
The GPT-6 Sol API is OpenAI's frontier GPT-6 reasoning route, with 1M context, image input, and tool use.
GPT-6 Sol is OpenAI's September 22, 2026 release for complex coding and agent workflows, sold as gpt-6-sol. It sits under GPT-6 Astra in the three-model GPT-6 family, next to the cheaper GPT-6 Luna, and shares their 1,050,000-token context window, 128,000-token output ceiling and image input. What separates it is the effort dial: none, low, medium, high, xhigh and max, with medium as the default, so a request can run without reasoning tokens at all.
Pick GPT-6 Sol when a job has connected decisions: debugging across modules, a feature behind compatibility constraints, or several tool results that must be reconciled. GPT-6.1 Sol is the better default for new work, with lower cache-read rates and a cutoff ten days later, and GPT-6 Luna covers bounded extraction. Sol keeps two options that GPT-6.1 Sol dropped: the none effort level, and function calling through Chat Completions while reasoning_effort is none.
Best-fit coding workloads
Multi-service bug hunts
Follow a failure across packages: put the stack traces, the call sites and the recent diffs in one request, then ask for a ranked list of causes before any edit. The 1M window holds the whole trace, and medium effort is enough to start. Require a reproduction command with each theory and run it before accepting a fix.
Tool-heavy data gathering
Chain search, shell and database calls in one agent run and reconcile the results at the end. Function calling works through Chat Completions when reasoning_effort is none, so a deterministic loop does not need the Responses API. Label every tool result so the closing summary can be checked against its source.
Compatibility-constrained features
Implement a change under constraints: no public interface breaks, migrations must replay, older clients keep working. List the constraints first, ask for the smallest patch that satisfies them, then read the diff for unrelated edits. Raise effort only when the first patch fails a constraint.
02
Hands-on notes
Checked on 2026-10-27 through the OmniaKey API with one standard coding prompt (median of 3 runs) and three capability probes.
- Output tokens for our standard coding prompt, reasoning included
- 195
- Cost of that output at current prices
- $0.0003
- JSON mode
- Passed
- Tool calling
- Passed
- Image input
- Passed
03
Technical specification
Catalog facts and integration details verified for this route.
- Model ID
- gpt-6-sol
- Context
- 1M
- Inputs and tools
- Vision · Tool use
- API endpoint
- /v1/chat/completions
- Cache hit / 1M
- $0.045 USD
- Coding clients
- Codex · Cursor · Cline · Aider
Limits to plan around
- Cache reads are listed above GPT-6.1 Sol's, so an agent loop that resends the same prefix spends more on the older model.
- The knowledge cutoff is April 20, 2026; later library and API changes have to be supplied in the prompt.
- Function calling on Chat Completions only works with reasoning_effort set to none. A request that needs reasoning and tools together must use the Responses API.
- Reasoning tokens are billed as output and occupy the window, so a long investigation can cost much more than its visible answer suggests.
04
Compare nearby models
Compare workload fit and current listed token rates before choosing a route.
| Model | Best for | Context | Input | Output |
|---|---|---|---|---|
| GPT-6 SolThis page gpt-6-sol | The original GPT-6 coding model, still the pick for pinned agents and none-effort tool loops. | 1M | $0.225 USD Official price $2 USD | $1.35 USD Official price $10 USD |
| GPT-6.1 Sol gpt-6.1-sol | Newer and cheaper on cache reads, with a later cutoff, but it drops the none effort level. | 1M | $0.225 USD Official price $2 USD | $1.35 USD Official price $10 USD |
| GPT-6 Luna gpt-6-luna | For bounded extraction and classification where a cheap validator settles the answer. | 1M | $0.2 USD Official price $0.1 USD | $1.2 USD Official price $0.5 USD |
| GPT-6 Astra gpt-6-astra | The flagship for the hardest, most expensive-to-repair work, listed at the top of the family. | 1M | $0.9 USD Official price $10 USD | $4.5 USD Official price $50 USD |
05
SDK quickstarts
Use one base URL and model ID from cURL, Python, or TypeScript.
curl https://api.omniakey.com/v1/chat/completions \
-H "Authorization: Bearer $OMNIAKEY_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-6-sol",
"messages": [
{"role": "user", "content": "Review this pull request"}
],
"stream": true
}'06
Estimate token cost
Enter expected input and output tokens to compare current listed rates.
- OmniaKey estimate
- $0.0495
- Official-rate estimate
- $0.40
- Estimated savings
- $0.3505
Estimate covers input and output tokens only. Cache usage, retries, tools, and client-side token accounting can change the final charge.
07
Related coding guides
Deeper selection, setup, and troubleshooting guidance for this model family.
GPT-6 Sol Review
Review the release, API costs and coding uses of GPT-6 Sol.
Read guideGPT-6 Sol vs Astra: Which Should You Use?
Sol is the economical starting point; Astra earns a trial when a failed or incomplete task is expensive.
Read guideGPT-6 Sol vs Luna
Start with the task's verification cost, then decide whether Sol's higher rate is worthwhile.
Read guide08
Sources and verification
Model facts and links were checked on 2026-10-27. Provider documentation remains the authority for upstream behavior.
Frequently asked questions
How much does GPT-6 Sol cost on OmniaKey?
OmniaKey currently charges $0.225 USD per 1M input tokens and $1.35 USD per 1M output tokens, in USD. Direct provider rates are separate and may change with input context length.
What is the context window for GPT-6 Sol?
The listed context window is 1M. Actual usable limits can also depend on the client and upstream request format.
When was GPT-6 Sol released and which model id does it use?
OpenAI's changelog records September 22, 2026 for gpt-6-sol, the same day as GPT-6 Luna. Send POST /v1/chat/completions to https://api.omniakey.com/v1 with that id, or use POST /v1/responses when a request combines reasoning with tools. The id is case-sensitive and different from gpt-6.1-sol.
Is GPT-6 Sol still worth using now that GPT-6.1 Sol exists?
Yes for two narrow cases: an agent built on the none effort level, and Chat Completions function calling with reasoning_effort set to none. Otherwise GPT-6.1 Sol lists the same input and output rates, lower cache reads and a cutoff ten days later. Compare accepted tasks before moving a pinned integration.
GPT-6 Sol or GPT-6 Astra for coding?
Astra holds the higher tier and OpenAI positions it for the hardest end-to-end work, while Sol lists much lower rates with the same context and output limits. Start on Sol where the task has a clear test, and move to Astra when a failed attempt costs more than the extra tokens. Astra does not offer the none setting at all.
How is GPT-6 Sol billed?
By input, output and cached-input token, plus a separate cache-write charge. Reasoning tokens count as output, and cache reads are charged far below plain input. Batch and Flex are listed below Standard and Fast mode above it. Current rates sit in the price table on the model page.
Does GPT-6 Sol accept images?
It accepts text and images and returns text. Screenshots, diagrams and photos can travel in the same request as code or logs. It does not return images, because generating one is a separate operation on an image model. OpenAI reported an image-encoding fix for Sol and Luna on September 25, 2026, so visual tests made before that date are worth repeating.