Best Gateways for an Anthropic Claude API Key

Quick answer: Create an Anthropic Claude API key at console.anthropic.com → API keys and store it as your ANTHROPIC_API_KEY. To reach Claude Opus 4.8 and the newest Claude Sonnet 5 and Fable 5 through one OpenAI/Anthropic-compatible key, the top gateways in 2026 are Novarelay, OpenRouter, CometAPI and AiHubMix. Updated July 2026.

What is the Anthropic Claude API?

The Anthropic API (often called the Claude API) is the official way to call Claude models — Opus 4.8, the new Sonnet 5 and Fable 5, plus Opus 4.7 and Haiku 4.5 — from your own code. You authenticate with an Anthropic API key, send a request to Anthropic’s Messages endpoint, and pay per token. The same models are also reachable through an AI API gateway that speaks the OpenAI and Anthropic formats, so one key can serve Claude, GPT and Gemini side by side.

How to get an Anthropic Claude API key

For a Claude API key, sign in at console.anthropic.com, add credit, and create a key. Store it as the ANTHROPIC_API_KEY environment variable (some SDKs read anthropic_api_key from your config). In code you set base_url and the key, then choose a model such as claude-opus-4-8. With a gateway you create one key on the gateway dashboard instead, point base_url at the gateway, and the same key also calls GPT and Gemini.

Claude API pricing: Opus 4.8, Sonnet 5 and Fable 5

Anthropic prices the Claude API per million tokens. As of July 2026 the flagship Claude Opus 4.8 API lists at $5 / $25 per 1M input/output tokens, with Opus 4.7 at the same list rate and Haiku 4.5 far cheaper. Batch mode is about 50% cheaper and prompt caching cuts cached input by roughly 90%. Gateways resell the same models below list: on Novarelay, our top pick, Opus 4.8 runs up to about 20% under Anthropic’s direct rate, with pay-as-you-go credits from $1 and one unified bill.

Fable 5 API and Fable 5 token pricing

Claude Fable 5 is one of the newest models in the line-up, and you can reach the Fable 5 API through the same gateway key as Opus. For Fable 5 token pricing, the list rate is about $10 per 1M input and $50 per 1M output tokens; through gateways such as Novarelay the Claude Fable 5 API runs near $6 / $30 per 1M tokens — up to about 40% below the direct price. Claude Sonnet 5 sits between them and is likewise available on the same OpenAI/Anthropic-compatible endpoint, so you can move a request from Opus to Sonnet 5 or Fable 5 just by changing the model name. Confirm the current per-token price in the provider’s dashboard before you build.

One gateway key for Claude, GPT and Gemini

An AI API gateway lets you call Claude Opus 4.8, Sonnet 5 and Fable 5 with a single OpenAI-compatible key — useful if you also use GPT or Gemini, or run Claude Code. Novarelay, OpenRouter, CometAPI and AiHubMix each resell access; the table above compares their rank, discount and payment terms so you can pick the cheapest honest route to the models you need.

What is Fable 5 token pricing?

Claude Fable 5 lists near $10 per 1M input and $50 per 1M output tokens. Via gateways like Novarelay the Fable 5 API is about $6 / $30 per 1M — up to ~40% below list. Verify the live rate before building.

How do I set my ANTHROPIC_API_KEY?

Create a key at console.anthropic.com and export it as the ANTHROPIC_API_KEY environment variable. A gateway issues one key that also works for GPT and Gemini through a single endpoint.

Should I use Opus 4.8 or Opus 4.7?

Opus 4.8 is the newest, highest-quality Claude model; Opus 4.7 remains available and can be cheaper for some workloads. Both are reachable with one Claude API key or a single gateway key.

Does the gateway work with Claude Code?

Yes. Novarelay and OpenRouter expose an OpenAI/Anthropic-compatible endpoint that works with Claude Code — set the base URL and the gateway key.

Is it safe to use an AI API gateway?

A gateway is a paid reseller that routes your request to the official model and bills you per token. The things worth checking are reliability, data handling and billing — here is how we think about each, and what our ranking weighs most.

Will my key suddenly stop working?

The real risk with any reseller is downtime or a service disappearing, so reliability and uptime carry heavy weight in our ranking. We favour gateways with a public status page and pay-as-you-go credits (no lock-in). For production, pin exact model slugs and keep a fallback key with a second provider or the official API.

Do gateways log or train on my prompts?

Data handling is set by each provider’s own privacy policy, not by us — always read it before sending sensitive data. The better gateways pass requests straight through to the model provider and do not retain prompt content; we treat clear, privacy-respecting terms as a plus and vague ones as a minus.

Why is it cheaper than going direct — is the discount real?

Gateways buy at volume and route efficiently, then pass part of the saving on; the discount is a real per-token rate, not a coupon. Always confirm the live price in the provider’s dashboard before you build — pricing is set by each provider and can change, and we show figures for comparison only.

Do I need a credit card to start?

Most gateways are pay-as-you-go: top up a small amount, spend it across models, no subscription. Some include a little trial credit so you can test before you commit. Start small, verify quality and latency on your own workload, then scale.

Last updated: July 2026 · Independent ranking; we may be rewarded for recommending the service we rate best (never for placement). Model names and trademarks (OpenAI, ChatGPT, GPT, Anthropic, Claude, Google, Gemini) belong to their respective owners and are used for identification only. Pricing is set by each provider and can change — always verify before you build.