A proxy
for Claude,
and nothing else.
ClaudeOpus stands between your code and Anthropic's API. It routes, meters, and caches — then gets out of the way. Your SDK keeps its shape; your keys keep their limits.
Three lines of config
# ~/.claude/settings.json ANTHROPIC_BASE_URL=https://api.claudeopus.pro ANTHROPIC_AUTH_TOKEN=sk-ant-co-... ANTHROPIC_MODEL=claude-opus-4-6
Works with any client that speaks the Anthropic messages API. If yours doesn't, there's an OpenAI-shaped endpoint too.
The design, in short.
— 01
One endpoint, every model
Swap a single base URL and every Anthropic client sees Opus, Sonnet, and Haiku. No forks of your SDK, no custom routing layer, no vendor glue.
— 02
Budgets that actually hold
Each API key enforces a rolling five-hour token window and a per-minute request ceiling. When a team burns through their quota, they stop — not the proxy, not the upstream.
— 03
Built for multi-tenant use
Admins mint keys. Resellers mint keys for their users. Everyone sees their own usage. No one sees the ones above them.
The lineup.
| Tier | Model ID | When to reach for it |
|---|---|---|
| Opus | claude-opus-4-6 | Deep reasoning, synthesis, long horizons. |
| Sonnet | claude-sonnet-4-6 | Balanced — the default for most prompts. |
| Haiku | claude-haiku-4-5 | Low latency, high throughput. |
Any model ID Anthropic publishes, you can request. The proxy accepts them all.
What's in the box,
in plain text.
No surprises. No feature flags. Everything below is live for every key from the moment it's issued.
- 01Streaming SSE passthrough (zero added latency)
- 02Prompt caching — cached tokens never count against budget
- 03Per-key rate limits and expiry
- 04Rolling five-hour token windows
- 05Reseller hierarchy with parent/child quotas
- 06Server-side web search and image analysis
- 07Drop-in for Claude Code, Cursor, Windsurf, Cline
- 08OpenAI-shaped endpoints for legacy clients
— on routing —
“The best infrastructure is the kind you forget about. ClaudeOpus is meant to be forgotten.”
From the README
Sixty seconds
is a generous estimate.
Install the wizard, paste your key, and pick your editor. The proxy does everything else.
$ npx claudeopus → Enter your ClaudeOpus API key: █
