claude-apilisted
Install: claude install-skill CodeWithBehnam/cc-docs
# Claude API
Build applications with the Anthropic Claude API and SDKs.
## When to Activate
- Building applications that call the Claude API
- Code imports `anthropic` (Python) or `@anthropic-ai/sdk` (TypeScript)
- User asks about Claude API patterns, tool use, streaming, or vision
- Implementing agent workflows with Claude Agent SDK
- Optimizing API costs, token usage, or latency
## Model Selection
| Model | ID | Best For |
|-------|-----|----------|
| Opus 4.6 | `claude-opus-4-6` | Complex reasoning, architecture, research |
| Sonnet 4.6 | `claude-sonnet-4-6` | Balanced coding, most development tasks |
| Haiku 4.5 | `claude-haiku-4-5-20251001` | Fast responses, high-volume, cost-sensitive |
Default to Sonnet 4.6 unless the task requires deep reasoning (Opus) or speed/cost optimization (Haiku).
## Python SDK
### Installation
```bash
pip install anthropic
```
### Basic Message
```python
import anthropic
client = anthropic.Anthropic() # reads ANTHROPIC_API_KEY from env
message = client.messages.create(
model="claude-sonnet-4-6",
max_tokens=1024,
messages=[
{"role": "user", "content": "Explain async/await in Python"}
]
)
print(message.content[0].text)
```
### Streaming
```python
with client.messages.stream(
model="claude-sonnet-4-6",
max_tokens=1024,
messages=[{"role": "user", "content": "Write a haiku about coding"}]
) as stream:
for text in stream.text_stream:
print(text, end="", flush=True)
```
### System Promp