Unlimited Claude API key: plans, limits and setup

A CAK unlimited API key uses a timed Claude Unlimited plan. You pay for an access period instead of a per-token charge on that subscription group. Here is how to choose the right key, activate access and verify the connection.

Reviewed 2026-10-26 · Claude API documentation

What the plan covers

The subscription belongs to your CAK account and access group. Your API key authenticates requests to that group. The plan clock and the account’s service limits still matter, even though calls covered by the plan do not have a per-token bill.

This is independent API gateway access for applications and developer tools. It is separate from Anthropic direct billing and from a Claude.ai consumer subscription.

Choose an access period

Prices shown here are the current CAK plan list in USD. Confirm the final currency, payment method and any checkout charges before paying. Choose the period around when you intend to work; do not assume unused time carries over.

Activate access and create the correct key

1. Create a CAK account or sign in with Google, and complete any required email verification.
2. Open Purchase, choose a timed plan and complete payment. Check that the subscription is active before starting a long task.
3. Open API Keys and create a key assigned to Claude Unlimited. A key attached to another group does not automatically use this plan.
4. Store the key privately. Run the model-list request from the API starter, then send one short request using an ID returned for your key.

Rate limits and practical use

The group currently allows 60 requests per minute. Account concurrency is a separate control. Opening several coding agents can consume those limits faster than one conversation. A model being listed is not a promise that every upstream request will succeed.

For a 429 response, pause new requests and check the account’s active work. Respect Retry-After when it is present. Use bounded retries with backoff for transient failures; repeatedly retrying an authentication or expired-plan error will not fix it.

CAK web chat is available with eligible active plans and allows one active response per user. API clients have their own account and group limits.

Connect your tools

For Claude Code, use the root base URL https://claudeapikey.dev with your CAK credential. Follow the Windows and macOS/Linux setup guide. For clients using Chat Completions, use the client-specific guide and the /v1 base URL.

Check /v1/models with the same key you will use for generation. Do not choose a model solely from a blog post or an old configuration file. Features, context limits and availability depend on that model and the route.

When prepaid credits fit better

A timed plan is useful when you expect concentrated work in a known period. Prepaid credits can suit occasional calls or workloads that do not fit the subscription group. Compare your expected workload using the cost calculator, entering the current rates for your actual credit group.

Questions

Claude API is an independent gateway and is not affiliated with or endorsed by Anthropic. Claude and Anthropic are trademarks of their respective owners.