GPT-6 Astra API

Q: Which model ID should I use?

Use gpt-6-astra. There is no generic gpt-6 alias, and the same ID works on Chat Completions and Responses.

Q: How much does GPT-6 Astra cost on EvoLink?

EvoLink default-group rates are $9.000 input and $45.000 output per 1M tokens, against OpenAI’s $10.000 / $50.000 list price. Cache reads are $0.900 and cache writes $11.250 per 1M tokens; logged-in users see their own group rates.

Q: How is cached input billed?

Cache reads and cache writes are separate token segments. Neither segment is billed again as ordinary input.

Q: When do long-context rates apply?

When total prompt tokens exceed 272,000, the whole request uses the long-context multipliers: 2x for input and both cache roles, 1.5x for output.

Q: Which reasoning effort levels are supported?

reasoning_effort on Chat Completions and reasoning.effort on Responses accept low, medium, high, xhigh, and max. Higher effort spends more reasoning tokens, which are billed as output.

Q: What are the context window and maximum output?

GPT-6 Astra has a 1,050,000-token context window and up to 128,000 output tokens per request.

Access OpenAI GPT-6 Astra—also searched as GPT-6 / GPT 6 Astra / gpt-6-astra— through EvoLink's unified chat API. Test reasoning, coding, tool use before integrating.

OpenAIText GenerationAvailable

from $9.000 / 1M input tokens$10.000 official price-10%

API docs

Chat CompletionsResponses APIReasoning effortPrompt cachingTool use

Production routeLive

Live

Context

1.05M context · 128K max output

Best For

Frontier reasoning, agentic coding, computer use

Input

Text + images

Output

Text · JSON (structured output) · tool calls

Models Pricing Readme API

Choose GPT-6 Astra

One exact model ID on the OpenAI-compatible integration. Short- and long-context rates for all four token roles are listed on the card.

GPT-6 Astra

OpenAI's most capable model, built for the hardest end-to-end work.

Selected

Model ID

gpt-6-astra

Best for

Complex reasoning, agentic coding, computer use, research, and document creation

< 272K

Input

$9.000 / 1M-10%

612 cr / 1M$10.000official price

Cache read

$0.900 / 1M-10%

61.2 cr / 1M$1.000official price

Cache write

$11.250 / 1M-10%

765 cr / 1M$12.500official price

Output

$45.000 / 1M-10%

3060 cr / 1M$50.000official price

≥ 272K

Input

$18.000 / 1M-10%

1224 cr / 1M$20.000official price

Cache read

$1.800 / 1M-10%

122.4 cr / 1M$2.000official price

Cache write

$22.500 / 1M-10%

1530 cr / 1M$25.000official price

Output

$67.500 / 1M-10%

4590 cr / 1M$75.000official price

All rates are per 1M tokens, shown in USD and credits, and reflect your account's current pricing. Above 272K prompt tokens the long-context tier applies: ×2 for input and cache roles, ×1.5 for output.

GPT-6 Astra pricing

Estimate what one GPT-6 Astra request costs before you integrate. The calculator uses your account's current rates, with official pricing as a reference.

Request calculator

Enter the token mix for one request.

Input tokensCache read tokensCache write tokensOutput tokens

Estimated request cost

GPT-6 Astra

Short-context rate

USD$0.023

Credits1.5423

Official estimate $0.026 · save $0.0026 (10%)

Input tokens0.612 cr

Cache read tokens0.0123 cr

Cache write tokens0 cr

Output tokens0.918 cr

Minimum charge: 0.01 credits per request. At 272K prompt tokens, input and cache roles are billed at ×2 and output at ×1.5. Tool calls are not multiplied.

Budget guide

Approximate requests using the current token mix.

Add credits

$10

About 440 requests

For quick testing

$50

About 2204 requests

For regular development

$100

About 4408 requests

For production evaluation

GPT-6 Astra API

OpenAI's most capable model, built for the hardest end-to-end work — complex reasoning, agentic coding, computer use, research, and document creation — available through one EvoLink API key with Chat Completions and Responses.

GPT-6 Astra is served on EvoLink under the model ID gpt-6-astra through Chat Completions · Responses, with the same API key and balance you use for every other model. It offers a 1.05M context window and up to 128K output tokens, plus reasoning, coding, tool use.

GPT-6 Astra specs and capabilities

Numbers come from the EvoLink route configuration; capabilities are what the API exposes today.

Context window: 1.05M tokens
Max output: 128K tokens
Input: Text + images
Output: Text · JSON (structured output) · tool calls
Reasoning: Configurable reasoning effort
Tool use: Function calling with multi-step tool sequences
Prompt caching: Cache write + cache read rates
Long-context tier: ×2 in / ×1.5 out above 272K prompt tokens
Protocols: Chat Completions · Responses
Model ID: gpt-6-astra

What GPT-6 Astra is best for

One exact model ID for the hardest end-to-end work; keep routine or latency-sensitive traffic on a lighter route.

Complete Complex Coding Tasks

Work across multi-file changes, tests, debugging, and long-running implementation tasks instead of stopping at a plausible code suggestion.

Keep Working While Tools Run

With async tool calling, Astra can reason or handle independent work while your application runs a slow function or custom tool, then reconnect the result by call ID.

Use Long Project Context

Keep more repository, documents, requirements, and tool results available inside a 1.05M-token window; retrieval and constraint retention still need workload testing.

Research and Produce Artifacts

Combine browsing, code, data analysis, and scientific reasoning, then create or revise documents, spreadsheets, presentations, websites, and other structured deliverables.

Two ways to use GPT-6 Astra: EvoLink API or Agent

Use the EvoLink API for product backends and batch jobs, or call GPT-6 Astra from Codex, Claude, or Gemini for coding and analysis workflows. Both paths share the same EvoLink API key, balance, model ID, and request history.

Option 1

Integrate with the EvoLink API

Best for: product backends, batch jobs, automated pipelines

Send OpenAI-compatible Chat Completions (or Anthropic Messages) requests to EvoLink and control the model ID, system prompt, output budget, tools, and structured output.

1Create an EvoLink API key in the console
2Point your OpenAI or Anthropic SDK at the EvoLink base URL and select the model ID shown above
3Send one representative request and read the usage field for input, cached, and output tokens
4Set max_tokens and retries per task; keep tool-call IDs and results across turns

Create EvoLink API Key

Option 2

Call it with an Agent

Best for: coding, review, and analysis tasks in Codex, Claude, and Gemini

Give the Agent the task, the inputs to include, and the acceptance criteria. It assembles the request, calls GPT-6 Astra through EvoLink, and returns the answer with token usage.

1Set EVOLINK_API_KEY in your local environment; never put it in code or a prompt
2Describe the task, the inputs to include, and the expected output format
3Ask the Agent to call GPT-6 Astra through EvoLink and show the request before sending
4Let the Agent report the answer, token usage, and any error body

GPT-6 Astra API code example and error handling

This example shows the shortest runnable request: an OpenAI-compatible Chat Completions call with a system prompt, a user message, and an output budget. Open the API tab for the complete parameter and response reference.

View complete API docs

cURL

curl -X POST https://api.evolink.ai/v1/chat/completions \
  -H "Authorization: Bearer $EVOLINK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6-astra",
    "messages": [
      { "role": "system", "content": "You are a senior engineer reviewing a pull request." },
      { "role": "user", "content": "Review this diff and list the blocking issues with file and line:\n<diff>" }
    ],
    "reasoning_effort": "high",
    "max_tokens": 4096
  }'

# There is no generic gpt-6 alias: use the exact ID gpt-6-astra on both
# Chat Completions and Responses. reasoning_effort accepts low, medium,
# high, xhigh, and max; reasoning tokens are billed as output. The
# response includes choices[0].message and a usage object (prompt_tokens,
# completion_tokens, and cached tokens when a prefix is reused).

Invalid request or unsupported parameter

Check the model ID, the messages array, and parameter ranges against the API reference; remove fields this route does not support.

Authentication or balance issue

Check the Authorization bearer token and confirm the available balance in the console.

Context length exceeded

Prompt tokens exceed the GPT-6 Astra context window. Trim or retrieve only the relevant evidence and reuse cached prefixes.

Rate limited (429)

Back off and retry with jitter; batch or queue requests instead of sending parallel bursts.

Content or tool call rejected

Review sensitive content, malformed tool-call arguments, and JSON schema mismatches before retrying.

Before you take GPT-6 Astra to production

Four checks that decide cost and stability.

Pick the exact GPT-6 Astra model ID

Use gpt-6-astra on both Chat Completions and Responses; there is no generic gpt-6 alias.

Required

Budget for the 272K long-context threshold

Above 272K prompt tokens the whole request uses long-context rates; keep prompts under the line when you can.

Recommended

Structure prompts for cache reads

Put stable instructions and reference material first so cache reads replace full-price input on repeated calls.

Recommended

Measure with usage, not list price

Reconcile cost from the usage object (uncached input, cache read, cache write, output) before scaling traffic.

Required

Four-part prompt caching

Uncached input, cache reads, cache writes, and output are settled separately from the final usage object. Cache writes are not charged again as ordinary input.

Long-context threshold

At more than 272K prompt tokens, input and both cache roles use 2x rates while output uses 1.5x rates for the entire request.

GPT-6 Astra vs other frontier models

EvoLink

Compare GPT-6 Astra with Claude Fable 5.1 and GPT-5.6 Sol using EvoLink prices per 1M tokens.

Feature	GPT-6 Astra	Claude Fable 5.1	GPT-5.6 Sol
EvoLink price / 1M (input / output)	$9 / $45	$9.5 / $47.5	$4.5 / $27
Context window	1.05M	1M	1.05M
Prompt caching	Cache read + cache write	Cache read + 5m/1h cache write	Cache read + cache write
Best for	Complex reasoning, agentic coding, computer use, research, and document creation	Deep reasoning, long agentic sessions, and cache-heavy coding	Hard reasoning and coding agents on the previous GPT generation, with Sol, Terra, and Luna tiers

GPT-6 Astra

EvoLink price / 1M (input / output)$9 / $45

Context window1.05M

Prompt cachingCache read + cache write

Best forComplex reasoning, agentic coding, computer use, research, and document creation

Claude Fable 5.1

EvoLink price / 1M (input / output)$9.5 / $47.5

Context window1M

Prompt cachingCache read + 5m/1h cache write

Best forDeep reasoning, long agentic sessions, and cache-heavy coding

GPT-5.6 Sol

EvoLink price / 1M (input / output)$4.5 / $27

Context window1.05M

Prompt cachingCache read + cache write

Best forHard reasoning and coding agents on the previous GPT generation, with Sol, Terra, and Luna tiers

Base-context prices use the current EvoLink user group. Logged-in users see their group rates; signed-out users see Default rates. Long-context multipliers are listed in the Pricing section.

GPT Model Family

Same API key and balance — switch tiers without changing your integration.

Compare all GPT models

GPT-5.6

Sol, Terra, and Luna tiers — same integration, lower price points

View model

GPT-5.5

Previous flagship, 1M context

View model

GPT-5.4

Balanced predecessor with computer use

View model

Other text models on EvoLink besides GPT-6 Astra

Claude Fable 5.1

Anthropic flagship at the same official list price as Astra, with always-on adaptive thinking and a 1M context window.

View model

Kimi K3

Moonshot flagship reasoning route with a 1.05M context window, strong on visual front-end work and repository-scale coding.

View model

Gemini 3.1 Pro

Google flagship for multimodal reasoning and large-context workloads.

View model

Grok 4.6

xAI reasoning and tool-use route with server-side search for research and agent workflows.

View model

GPT-6 Astra API - FAQ

Which model ID should I use?

Use gpt-6-astra. There is no generic gpt-6 alias, and the same ID works on Chat Completions and Responses.

How much does GPT-6 Astra cost on EvoLink?

EvoLink default-group rates are $9.000 input and $45.000 output per 1M tokens, against OpenAI’s $10.000 / $50.000 list price. Cache reads are $0.900 and cache writes $11.250 per 1M tokens; logged-in users see their own group rates.

How is cached input billed?

Cache reads and cache writes are separate token segments. Neither segment is billed again as ordinary input.

When do long-context rates apply?

When total prompt tokens exceed 272,000, the whole request uses the long-context multipliers: 2x for input and both cache roles, 1.5x for output.

Which reasoning effort levels are supported?

reasoning_effort on Chat Completions and reasoning.effort on Responses accept low, medium, high, xhigh, and max. Higher effort spends more reasoning tokens, which are billed as output.

What are the context window and maximum output?

GPT-6 Astra has a 1,050,000-token context window and up to 128,000 output tokens per request.