Skip to main content

GPT-6 Astra on Felo OpenAPI: 1.05M Context, One Model ID

· 4 min read
Felo Search Tips Buddy
Felo Search Tips Buddy
Committed to answers at your fingertips

Felo OpenAPI adds GPT-6 Astra with a 1.05M context window, 128K max output, and compatible Chat Completions, Responses, and Messages endpoints.

GPT-6 Astra API infographic cover showing 1.05M context, 128K max output, $5 input, and $30 output

Long documents, complex code, and multi-step agent flows force teams to split model calls. Felo OpenAPI offers GPT-6 Astra, so one model ID can handle these workloads through compatible API surfaces.

Try GPT-6 Astra: https://openapi.felo.ai/models/openai/gpt-6-astra

What GPT-6 Astra is built for​

GPT-6 Astra is the flagship GPT-6 tier on Felo API Platform. The model page positions it for complex reasoning, advanced coding, long-context analysis, and high-capability agent workflows. It lists Reasoning, Tools, JSON, Streaming, and Vision as capabilities.

Use the model ID gpt-6-astra. The context window is 1.05M tokens and the maximum output is 128K tokens. This capacity lets a request hold a specification, a codebase summary, tool definitions, and conversation history in one working context.

Three protocols, one model ID​

Felo API Platform exposes three compatible request surfaces:

  • Chat Completions: POST https://openapi.felo.ai/api/v1/chat/completions
  • Responses: POST https://openapi.felo.ai/api/v1/responses
  • Messages: POST https://openapi.felo.ai/api/v1/messages

An app with an OpenAI-compatible client can keep its request structure and change the model value to gpt-6-astra. Claude-style clients can use the Anthropic-compatible Messages surface. The model page lists Claude Code, Codex, LLM API, and other agent clients as use cases.

Pricing that belongs in the budget​

The model page lists these rates:

ItemRate
Input$5.00 per 1M tokens
Output$30.00 per 1M tokens

The page says launch pricing may be up to 50% lower than official provider API rates. Final cost depends on the model, input/output mix, cache use, and active plan. A cost estimate includes each variable; the headline rate is not the full bill.

Make a first request in five steps​

1. Create an API key​

Create a key in your Felo API Platform account and set it as an environment variable:

export FELO_API_KEY="YOUR_API_KEY"

2. Set the endpoint​

For Chat Completions, use:

https://openapi.felo.ai/api/v1/chat/completions

3. Set the model ID​

Pass "model": "gpt-6-astra" with a messages array. This cURL request tests the route:

curl https://openapi.felo.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $FELO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6-astra",
    "messages": [{"role": "user", "content": "Explain this API error."}]
  }'

4. Add tools or structured output​

Compatible parameters include tools, tool_choice, and response_format. Support for each control depends on the selected protocol and model route. GPT-6 Astra supports reasoning; when the protocol and route expose reasoning controls, preserve returned reasoning metadata when continuing a conversation.

5. Turn on streaming​

Set stream to true to receive server-sent events:

{
  "model": "gpt-6-astra",
  "stream": true,
  "messages": [{"role": "user", "content": "Summarize this log."}]
}

A preflight checklist​

  • Estimate input cost against the 1.05M context window.
  • Set max_tokens to keep output within the project budget.
  • Record input, output, cache, and plan data for each request estimate.
  • Test prompts in the Playground before connecting an app or agent client.
  • Keep regression samples for tools, JSON output, and streaming.

Start with the model page​

GPT-6 Astra puts reasoning, coding, long-context analysis, and agent work behind one model entry. Felo OpenAPI gives teams a migration path through Chat Completions, Responses, and Messages. An existing client can stay in place while the request surface changes to match the workload.

Open the GPT-6 Astra model page for parameters, code samples, and the Playground entry.

Source: Felo API Platform, GPT-6 Astra model page (accessed 2026-09-03).