GPT-6 Astra API Access: One Key, Per-Token Billing, No Subscription (2026)
LivePair AI ·
GPT-6 Astra is one of the frontier text models in LivePair's catalog — call it through the standard chat-completions shape with a single prepaid `lp_` key, billed per token against the balance you load. No subscription, no separate provider account, and the same key unlocks Claude, Grok, Gemini, DeepSeek, Kimi, and 50+ other models.
What GPT-6 Astra is for
GPT-6 Astra sits in the frontier tier of the text catalog — the class of model you reach for when quality matters more than the per-token price: long-form drafting, complex instruction following, agentic tool-use loops, and code. For routine or high-volume traffic, cheaper tiers like GPT-5.4 Nano or DeepSeek Flash cover the same endpoint at a fraction of the rate.
The catalog exposes it as `openai/gpt-6-astra` — the provider-prefixed id convention every model on the platform shares, so switching models is a string change, not an integration change.
Calling it — the standard shape
The endpoint is `POST https://livepairai.com/v1/chat/completions` with `Authorization: Bearer lp_…` — the same request shape every chat client and agent framework already speaks. `model` takes `openai/gpt-6-astra`, `messages` is the usual array, and `max_tokens` doubles as a spend cap: billing is quoted from your max_tokens ceiling, so setting it tight sets the cost tight.
Because the shape is standard, any SDK or framework that lets you override `base_url` works — point it at `https://livepairai.com/v1` and the same code runs unchanged.
| Field | Value |
|---|---|
| Endpoint | POST https://livepairai.com/v1/chat/completions |
| Auth | Authorization: Bearer lp_… |
| Model id | openai/gpt-6-astra |
| Spend control | max_tokens caps the billed ceiling |
| Catalog | GET /v1/agent/models — free, live list |
One key, fifty models
The point of an aggregator key is the swap. Same request body, different `model` string: `anthropic/claude-sonnet-5.5` for the reasoning tier, `x-ai/grok-4.7` for Grok, `google/gemini-3.8-flash` for the fast cheap lane, `deepseek/deepseek-v4-pro` when you want open-weights economics, `moonshotai/kimi-k3` for long-context work.
The catalog endpoint returns the live list with per-million-token in/out rates — drive a model picker off it, or hardcode a shortlist and let users switch. Either way the comparison happens at runtime, not in a spreadsheet.
What it costs
Billing is per token against prepaid credits — load $5, spend down as you call. The response quotes come from your max_tokens cap times the model's out-rate, plus estimated input tokens at the in-rate; the ledger endpoint (`GET /v1/agent/balance`) shows the running balance and per-call history.
There is no seat fee and no monthly commitment — the model you call is the only thing you pay for. Compare that with provider-direct billing, which is the same arithmetic minus the multi-model key.
Agents can call it without a key
For agentic workloads there's a second rail: x402 settles each request in USDC on Base — a wallet-carrying agent pays per call with no `lp_` key and no account at all. The free tools (model catalog, job status) are free on both rails.
And for the humans, the same catalog is in the chat playground at livepairai.com — pick the model, type, done. The API and the UI share the same billing pool.
FAQ
- How do I call GPT-6 Astra via API?
- POST to https://livepairai.com/v1/chat/completions with Authorization: Bearer lp_… and model 'openai/gpt-6-astra'. The request shape is the standard chat-completions contract — existing SDKs and agent frameworks work by changing base_url.
- Do I need a subscription to use GPT-6 Astra?
- No — LivePair bills per token against prepaid credits starting at $5. There's no monthly tier; failed calls don't settle.
- What other models does the same key unlock?
- 50+ text models — Claude Sonnet 5.5, Grok 4.7, Gemini 3.8 Flash, DeepSeek V4, Kimi K3, GLM 5.3, Llama, Mistral — plus ~20 image and video models on the generation endpoints.
- Can an agent pay per call without an API key?
- Yes — the x402 rail settles each call in USDC on Base from a wallet signature, no account or key needed.