GPT-6 Astra API Pricing in TWD: Long Context and GPT-5.5

GPT-6 Astra is the next-generation reasoning model that OpenAI announced on September 3, 2026. BazaarLink made it available on September 5, 2026, with the model ID gpt-6-astra. OpenAI positions it for agent scenarios that require long, multi-step execution, such as computer use, browsing, software engineering, cybersecurity, science and professional knowledge work. Context window 1,050,000 tokens, maximum output 128,000 tokens, knowledge cutoff April 30, 2026. It is a "forced reasoning" model: every call thinks before it answers, this cannot be turned off, and temperature is not supported.

One-line verdict: if your work involves long agent workflows, reading an entire codebase or hundreds of pages of documents, and you need to push hallucination rates as low as possible, Astra is worth trying. For short tasks such as customer service, classification, summarization and translation, GPT-5.5 costs only one-half to six-tenths of Astra's price and is usually the better value.

Spec summary

TWD price list (per million tokens)

The exchange rate uses BazaarLink's site quote on September 5, 2026: USD/NTD = 31.63. Billing is in US dollars, quoted in New Taiwan dollars, and a Taiwan unified invoice can be issued.

Standard prompt (single request input ≤ 272K tokens)

Long-context prompt (single request input > 272K tokens)

Two things to note. First, the long-context tier is calculated on the entire request: once input exceeds 272K, the input and output of the whole request are billed at the higher tier, not only the portion above the threshold. Second, reasoning tokens count as output, and Astra's reasoning volume rises sharply as reasoning_effort goes up, so the actual bill is usually much larger than the length of the reply you see.

Compared with GPT-5.5: how much more, and when it is worth it

GPT-5.5 on BazaarLink costs $5 input / $30 output (about NT$158 / NT$949). Astra's standard tier is 2 times its input price and 1.67 times its output price; the long-context tier is 4 times its input price and 2.5 times its output price.

When to choose Astra

• Multi-step agents, computer use, browser automation, SRE / security tasks: this is the area where the official data shows the largest gap.
• Fitting more than 300K tokens of code or documents into a single request without splitting it.
• Research or legal document work where factual accuracy matters most and you would rather pay more than accept hallucinations.

When not to choose Astra

• Customer service chat, classification, extraction, translation and short summaries: the tasks are short and reasoning adds little, so the price gap shows up directly on the bill.
• Latency-sensitive interactive interfaces: Astra is a forced reasoning model, and time to first token is measured in seconds or even tens of seconds (see the data in the next section).
• Applications that need temperature to control sampling: Astra does not support this parameter.

Cost-saving suggestions: first run a round with medium to check quality, then decide whether high / xhigh is needed. Put the fixed system prompt and reference documents at the start of the conversation so they hit the cache (reads cost only $1). For requests above 272K, first evaluate whether they can be split into two requests.

Third-party evaluation data (as of 2026-09-20)

Artificial Analysis Intelligence Index: GPT-6 Astra (max) scores 52.7, second only to Claude Fable 5.1 (53.4). Scores and speed at different reasoning levels are as follows (all are Artificial Analysis site data as of 2026-09-20):

An Artificial Analysis evaluation article from 2026-09-03 also noted that Astra scores 67 on their Coding Agent Index (Fable 5.1 scores 70), and uses only one-third of the tokens GPT-5.6 Sol (max) uses when writing code. Its AA-Omniscience hallucination rate dropped from 92% in the previous generation to 51% (max effort). The same article, however, cautions that on the Intelligence Index, Astra's cost per question is about 75% higher than the previous generation while its score is nearly flat. Note: the Intelligence Index was 61 when that article was published, which differs from the 52.7 shown on the site now; this reflects a recalculation after an index revision, and this article uses the current site figures.

Figures published by OpenAI (quoted from a Vellum summary dated 2026-09-03; this site cannot read the official page directly): OSWorld 2.0 computer use 72.6% (previous generation 65.7%), ScreenSpot-Pro 92.7% (previous generation 76.9%), Terminal-Bench 4.0 57.7 (previous generation 37.3; Fable 5.1 at 55.8), GPQA Diamond 96.0%, FrontierMath Tier 4 97.6% (Fable 5.1 at 87.8%), Humanity's Last Exam 57.2% (Fable 5.1 at 65.0%, the only academic item in the official table where it loses to its rival). These figures are measured by the vendor itself, so treat them as directional references; actual results should still be judged by testing your own tasks.

Call example

BazaarLink's endpoint is compatible with the OpenAI SDK. Replace the base URL and set the model to gpt-6-astra:

curl https://bazaarlink.ai/api/v1/chat/completions \
  -H "Authorization: Bearer sk-bl-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6-astra",
    "reasoning_effort": "medium",
    "max_tokens": 16000,
    "messages": [
      {"role": "system", "content": "You are a senior backend engineer. Keep answers concise."},
      {"role": "user", "content": "Please review this code for concurrency issues: ..."}
    ]
  }'

Three common pitfalls:

1. Do not send temperature: Astra does not support this parameter. Remove it entirely rather than setting it to 1.
2. Leave room for reasoning in max_tokens: reasoning tokens consume this budget first. If it is set too small (for example 500), you get a response with empty content and finish_reason set to length, and you are still charged. For general tasks, at least 8,000 to 16,000 is recommended; for high and above, go higher.
3. Control cost with reasoning_effort, not by cutting max_tokens hard: what gets cut is the answer, not the thinking.

Getting started

Sign up on BazaarLink to top up in New Taiwan dollars and receive a Taiwan unified invoice. Use the same key to call gpt-6-astra, GPT-5.5, Claude, Gemini and other models, and review the tokens and cost of each request in the dashboard. Enterprise customers who need monthly billing or volume discounts are welcome to contact us.

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