Reference · Glossary
Anthropic API
Cloud API for **Claude models** — messages API with long context, system prompts, tool use, and vision inputs.
When to use
Long-document analysis, careful reasoning tasks, coding assistants, when Claude fits your eval benchmarks.
When not to
Identical to any API choice — pick based on evals, cost, latency, and compliance, not hype.
Example
client.messages.create(
model="claude-sonnet-4-20250514",
max_tokens=1024,
messages=[{"role": "user", "content": "Summarize this policy."}],
)