At a glance
- Sol’s standard input and output rates are one fifth of Astra’s.
- Sol tool calling requires the Responses API.
- Retries, human repairs and processing modes change total task cost.
Where Sol fits
OpenAI presents GPT-6.1 Sol as a balance of capability and cost, describing performance close to Astra. That comparison is a vendor claim, not a Youjie benchmark. The identifier is gpt-6.1-sol. Include it in trials for recurring coding and document workflows, and use difficult examples to determine where Astra remains worth the higher price. Source 1
Compare the same pricing basis
These are official Standard API rates in US dollars per million tokens at verification, not Youjie channel quotations. Source 1 Source 2
| Item | GPT-6.1 Sol | GPT-6 Astra |
|---|---|---|
| Uncached input | $2 | $10 |
| Cached input | $0.10 | $1 |
| Output | $10 | $50 |
This table excludes cache writes, tools and accelerated processing. Both pages document 1,050,000-token context windows and 128,000-token output limits. Above 272,000 input tokens, input and cache rates double and output rates increase by 1.5 times for the entire request.
A reproducible request example
Assume 100,000 uncached input tokens and 10,000 output tokens, Standard processing and no tool charges. Sol costs 0.1 × $2 + 0.01 × $10 = $0.30. Astra costs 0.1 × $10 + 0.01 × $50 = $1.50.
That fivefold difference holds for identical usage. It does not establish a fivefold saving per completed task: output length, retries and human repairs may differ. Retain actual usage and billing records alongside estimates.
Tool migration requires an interface check
Sol’s documentation directs tool calling to the Responses API. Chat Completions is supported without tool calling. Replacing only the model identifier in an existing tool client is therefore insufficient. Source 1
Supported reasoning levels are low, medium, high, xhigh and max, with medium as default; none and minimal are unsupported. Fast processing costs twice the applicable Standard rates, while Ultrafast costs six times those rates. Check the interface, parameters and processing mode together.
Route tasks using evidence
Compare routine structured tasks, multi-step tool workflows and difficult failure cases. Record acceptance rate, elapsed time, repair effort and total cost. Sol can become the default for categories it handles consistently; harder cases can follow an explicit escalation rule.
This staged approach connects lower unit prices to measured operational savings. It also avoids treating the vendor’s capability positioning as proof that every existing workflow can migrate unchanged.
Sources & verification
Primary materials consulted for this article. Vendor measurements are not independent Youjie tests.
- GPT-6.1 Sol model documentation ↗OpenAI · Documentation · Checked Oct 16, 2026
- GPT-6 Astra model documentation ↗OpenAI · Documentation · Checked Oct 16, 2026