Claude Opus 4.8 through the API

One key for both current Opus models

You reach the Claude Opus API through the standard Anthropic Messages API: set the base URL to https://router.apitoken.sale, authenticate with the x-api-key header, and pass claude-opus-4-8 as the model. apiToken.sale serves Opus 4.8 and Opus 4.7 on one prepaid key at a flat 50% off official token rates — no Anthropic account, no billing-country gate, no waitlist.

Opus is the tier you rent for work where a wrong answer costs more than tokens: architecture decisions, complex refactors, long autonomous agent runs. Routine tasks belong on a cheaper Claude, and section four of this guide covers that split.

See also: Claude Opus vs Sonnet: which model should you use?

What Opus costs per token here

Every request is metered against Anthropic's official rate card by its exact usage legs — input, output and cache — and the flat 50% B2C discount is subtracted before the charge hits your prepaid balance. Nothing is rounded up or bundled.

Prompt caching is metered as its own legs on the same rate card, and the discount applies to those as well:

Opus 4.8 keeps standard pricing across its full 1M-token context window — there is no long-context premium — and returns up to 128K output tokens per response. Adaptive thinking is the recommended mode, and thinking tokens bill as output.

Claude Opus 4.8 pricing in detail (cache rates, context, FAQ) →

Your first Opus request in two minutes

The wire format is Anthropic's own. If your code already talks to api.anthropic.com, you change exactly two things: the base URL and the key.

curl https://router.apitoken.sale/v1/messages \
  -H "x-api-key: sk-pool-•••" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-opus-4-8",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Review this diff for regressions"}]
  }'

Claude Code and other Anthropic-native tools pick the same settings up from the environment:

export ANTHROPIC_BASE_URL=https://router.apitoken.sale
export ANTHROPIC_API_KEY=sk-pool-•••

Tools that only speak OpenAI chat completions can use the OpenAI-compatible lane at https://router.apitoken.sale/v1 instead — Authorization: Bearer sk-pool-•••, same model ID. Either way the request draws from the same prepaid balance at the same discounted rate.

When Opus is worth it — and when it is not

• Complex refactors and multi-file changes where one mistake cascades through the codebase.
• Architecture, planning and high-stakes review work.
• Long agent sessions where consistency and prompt-cache reuse matter.
• An orchestrator or advisor pass that reviews and steers output from cheaper models.

For everyday coding, Sonnet 5 delivers near-Opus quality at 40% of the token price, and Haiku 4.5 covers high-volume, latency-sensitive work at one fifth of the Opus input rate. Because one key and one balance cover every tier, routing is a per-request decision — you change the model ID, not the provider.

Keeping long Opus sessions affordable

• Cache the stable prefix. System prompts, tool definitions and repo context belong behind a cache breakpoint: a cache read is officially $0.50 per 1M tokens on Opus instead of $5 for fresh input, and your discount halves that again.
• Only cache what repeats. A cache write costs more than plain input ($6.25 vs $5 per 1M officially), so a breakpoint pays off only when the same prefix is sent at least twice.
• Cap max_tokens to what the task actually needs, and summarize long threads instead of resending full history.
• Push subtasks down a tier: let Haiku or Sonnet handle search, extraction and drafts, and reserve Opus for the genuinely hard steps.

These tactics compound with the discount: caching and routing lower the token count, the 50% rate lowers the price per token, and every leg is visible in the dashboard usage breakdown.

Estimate an Opus workload before you run it →

Free start, prepaid after

1. 01Create an account with Google or GitHub — new accounts on those providers start with $5 of platform bonus credit, enough for genuine Opus calls. Email/password accounts do not receive the bonus.
2. 02Open the dashboard and generate a key (it looks like sk-pool-…). It activates instantly and works across supported Claude, GPT, Gemini and Kimi models.
3. 03Point your tool at https://router.apitoken.sale with that key and run a real Opus request against the bonus balance.
4. 04When the bonus runs low, top up any whole-dollar amount by bank card or crypto (USDT, BTC and other major coins) through the secure checkout provider. The balance never expires and there is no subscription.

If anything is unclear mid-setup, support answers in English and Russian via Telegram, or by email at apitokensale@gmail.com.

Frequently asked questions

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