Anthropic-compatible
An Anthropic-compatible API for the Messages format.
- POST /v1/messages
- Streaming and tool use
- 4 models
Setup
Two lines to switch
Anthropic-format base URL is https://api.claudech.com with no /v1 suffix. OpenAI-format clients use https://api.claudech.com/v1 instead.
import anthropic
client = anthropic.Anthropic(
base_url="https://api.claudech.com",
api_key="sk-...",
)
message = client.messages.create(
model="claude-opus-5-5",
max_tokens=1024,
messages=[{"role": "user", "content": "Hello"}],
)Compatibility
What works
Same request shapes as the Anthropic Messages API for the features below.
Messages
POST /v1/messages with role-based messages, max_tokens and optional parameters.
Streaming events
Enable streaming on Messages and consume Anthropic-style SSE events from the response.
Tool use
Define tools and let the model return tool_use blocks in the Messages response format.
Image input
User content can include image blocks alongside text on every model.
System prompts
Pass a system string or system blocks separate from the user and assistant turns.
1M-token context
Every model accepts up to one million tokens of context in a single request.
Models
Model rates
Prices are per million tokens, the same on every plan.
| Model id | Max output | Input / 1M | Cached input / 1M | Output / 1M |
|---|---|---|---|---|
claude-opus-5-5Fast and capable | 66K tokens | $0.50 | $0.010 | $1.90 |
claude-fable-5-1Advanced reasoning | 131K tokens | $0.50 | $0.010 | $1.90 |
claude-opus-5Deep reasoning | 131K tokens | $0.50 | $0.010 | $1.90 |
claude-sonnet-5Fast responses | 33K tokens | $0.50 | $0.010 | $1.90 |
Using Claude Code? See Claude Code with Claudech and the Claude Code integration guide. Also see SDK examples and the migration guide.
FAQ
Frequently asked questions
Is Claudech affiliated with Anthropic?
No. Claudech is an independent service and is not affiliated with, endorsed by or sponsored by Anthropic. It implements the public Messages request format so the Anthropic SDK, Claude Code and similar tools keep working when you change the base URL and key.
Which base URL does the Anthropic SDK need?
https://api.claudech.com, with nothing after it. The SDK adds /v1/messages itself. Do not use the OpenAI-format address ending in /v1.
Authorization: Bearer or x-api-key?
Both work on every endpoint. Send your sk- key as Authorization: Bearer sk-... or as x-api-key: sk-.... Claude Code often uses ANTHROPIC_AUTH_TOKEN (Bearer) or ANTHROPIC_API_KEY (x-api-key).
How am I billed?
Every request is billed per token from your prepaid balance at the model rates in the table below. Cached input is billed at the lower cache rate automatically. The Usage page itemises each request. Purchased tokens never expire.
What is not supported?
Embeddings, image generation, audio, files and the OpenAI Responses API are not offered. Messages (including streaming, tool use, system prompts and image input) and the model list are.
When can I create an API key?
Sign up with an email, then buy any token package once. That unlocks API keys on your account. There is no separate API subscription.
Point your Anthropic client at Claudech
Create an account, buy any token package to unlock API keys, and set the base URL to https://api.claudech.com.