8 concepts, live from D1
Concepts
Every real API billing concept catalogued here, grouped by category unless filtered.
Token-Based Pricing
| concept | description |
|---|
| Input tokens are typically billed at a different rate than output tokens | Most LLM API providers, including Anthropic, bill output tokens at a materially higher per-token rate than input tokens, because generating tokens is more computationally expensive than processing them as input. |
| Prompt caching reduces effective cost for repeated context | When a prompt prefix is cached (see subagentcontext.com's prompt-caching concept), reusing that cached prefix across requests is billed more cheaply than reprocessing the same tokens fresh each time. |
| Token-based pricing | The Anthropic API bills usage based on the number of tokens processed, not a flat per-request fee — both the tokens sent in a request (input) and the tokens generated in the response (output) count toward billed usage. |
Prepaid Credits
| concept | description |
|---|
| How prepaid credits are consumed | Credits are consumed continuously as API calls are made — each call's token-based cost (input + output tokens at that model's rate) is deducted from the account's remaining credit balance in near-real-time. |
| Prepaid credits on the Anthropic Console | API usage on the Anthropic Console is typically funded by prepaid credits — an organization adds credits to its account balance, and API usage is deducted from that balance as requests are made. |
Usage Tiers / Rate Limits
| concept | description |
|---|
| Monitoring usage and spend | The Anthropic Console provides usage and cost visibility so an organization can track token consumption, spend against its prepaid balance, and rate-limit headroom over time. |
| Rate limits apply per organization and per model | Rate limits are generally enforced per organization (not per individual API key) and can vary by model — a higher-capability model may have lower throughput limits than a smaller, faster model even within the same usage tier. |
| Usage tiers scale rate limits with usage history | API accounts are commonly placed into usage tiers that determine their rate limits (requests per minute, tokens per minute, etc.) — higher tiers generally unlock higher throughput. |
Machine-readable: GET /api/billing-concepts