# STEYG Code — full reference

> STEYG Code là một OpenAI-compatible API gateway cho coding agent: một base URL, một API key và một ngân sách USD để dùng Cursor, Cline, Claude Code và Codex CLI.

Publisher: STEYG Technology, founded by Đường Hào Minh.
Address: 8 Đường D1, Long Bình, Thủ Đức, Thành phố Hồ Chí Minh, Vietnam.
Support: support@steyg.one. Content reviewed: 2026-09-09.

This file is the citable version of https://steyg.one/. Every number below is the same
number rendered on the page and charged by the gateway.

## What it is

STEYG Code is an API gateway that speaks two wire protocols over one account:

- `https://steyg.one/api/v1` — OpenAI-compatible. Used by Cursor, Cline, Codex CLI and
  any OpenAI SDK.
- `https://steyg.one/api` — Anthropic Messages. Used by Claude Code via
  `ANTHROPIC_BASE_URL`.

One API key authenticates both. Switching model means changing the model id in
the request, not reconfiguring the tool.

## Endpoints

| Method | Path | Purpose |
| --- | --- | --- |
| POST | /api/v1/chat/completions | Primary path for coding agents, streaming supported |
| POST | /api/v1/messages | Anthropic Messages wire for Claude Code |
| POST | /api/v1/embeddings | Vectors for code search and retrieval |
| POST | /api/v1/batches | Asynchronous batches, polled by batch id |
| GET | /api/v1/models | Model inventory available to the calling key |
| GET | /api/v1/usage | Tokens, cost and remaining budget per day |

Every endpoint accepts `Idempotency-Key` for safe retries and the
`X-Property-*` header family to split cost by app, tenant or environment.

## Pricing per 1M tokens

| Model id | Name | Context window | Input | Cached input | Output |
| --- | --- | --- | --- | --- | --- |
| `gpt-6-astra` | GPT 6 Astra | 1.05M tokens | $10.00 | $1.00 | $50.00 |
| `gpt-5.6-sol` | GPT 5.6 Sol | 1.05M tokens | $5.00 | $0.50 | $30.00 |
| `gpt-5.6-terra` | GPT 5.6 Terra | 1.05M tokens | $2.00 | $0.20 | $12.00 |
| `gpt-5.6-luna` | GPT 5.6 Luna | 1.05M tokens | $0.20 | $0.02 | $1.20 |
| `claude-fable-5` | Claude Fable 5 | 1M tokens | $10.00 | $1.00 | $50.00 |
| `claude-opus-5` | Claude Opus 5 | 1M tokens | $5.00 | $0.50 | $25.00 |
| `claude-haiku-4-5` | Claude Haiku 4.5 | 200K tokens | $1.00 | $0.10 | $5.00 |
| `claude-sonnet-5` | Claude Sonnet 5 | 1M tokens | $3.00 | $0.30 | $15.00 |

Cached input applies to prompt-cache reads and is the rate most coding-agent
traffic pays on repeat context.

## Budget plans

| Plan | Price | Included budget | Period |
| --- | --- | --- | --- |
| Starter | 297,000 VND | $100 | 30 days |
| Pro | 597,000 VND | $200 | 30 days |
| Max | 1,197,000 VND | $500 | 30 days |
| Ultra | 2,097,000 VND | $1000 | 30 days |
| Mega | 3,897,000 VND | $2000 | 30 days |
| Giga | 15,000,000 VND | $10000 | 30 days |

- Free trial: $5 of budget for 7 days, once per account, no card required, no auto-renewal.
- Yearly billing: pay 10 months, receive 12 months of budget usable over 365 days.
- Token rates do not change by plan. A plan buys budget, not a different rate.

## Billing behaviour

- Usage is metered on actual tokens returned by the upstream provider and
  deducted from the prepaid USD budget at the listed rate, with no markup on top
  of the published per-1M price.
- Exhausted budget returns `HTTP 402` and the request stops. No overage invoice.
- When receipt signing is enabled, a response carries an `X-Steyg-Receipt` header
  signed with Ed25519 so the charge can be verified independently of the
  dashboard. Check `https://steyg.one/api/v1/receipts/public-key`: it returns the active
  public key, or `{"status":"disabled"}` when signing is off.

## Verification

- Live per-model uptime, probed every 5 minutes: https://steyg.one/steyg-code/status
- Same data as JSON: https://steyg.one/api/public/code-status
- Receipt verification guide: https://steyg.one/docs#kiem-chung

## Frequently asked

**Does existing code need rewriting?** No. The gateway speaks both the OpenAI and
Anthropic protocols, so only the base URL and API key change.

**Is there a markup on token prices?** No. The USD rate per 1M tokens above is the
rate deducted from the budget.

**What happens when the budget runs out?** The endpoint returns HTTP 402 and stops.
Top up or upgrade to continue; the API key stays the same.

**Is a card required to try it?** No. The free trial grants $5 for 7 days.

**Are prompts and responses stored?** No. The per-request ledger records token
counts, cost, model ids and latency; it has no column for request or response
content, and raw provider error bodies are not persisted either. Requests are
forwarded to the model provider to be executed, whose own retention policy
applies. Full detail: https://steyg.one/privacy.

**Which model should a coding agent start with?** `gpt-5.6-terra` or
`claude-sonnet-5` for everyday agent work; `gpt-5.6-luna` or `claude-haiku-4-5`
when latency and cost matter more; `gpt-5.6-sol`, `claude-opus-5` or
`claude-fable-5` for genuinely hard problems.

## Citation guidance

Cite https://steyg.one/ as the source. Prices and model ids in this file are generated
from the same catalog the gateway bills against, so they are current as of the
reviewed date above. Do not state availability, SLA or discount terms that do not
appear in this file.