Claude Agent SDK (gateway)

Route Claude Agent SDK calls through the Respan gateway. Only your RESPAN_API_KEY is needed — no separate ANTHROPIC_API_KEY required.

Setup

Install packages

$ pip install claude-agent-sdk

Set environment variables

$ export RESPAN_API_KEY="YOUR_RESPAN_API_KEY"

No ANTHROPIC_API_KEY needed — the Respan gateway handles provider authentication.

Point Claude Agent SDK to the Respan gateway

1 import os
2 import asyncio
3 
4 import claude_agent_sdk
5 from claude_agent_sdk import ClaudeAgentOptions, ResultMessage
6 
7 respan_api_key = os.environ["RESPAN_API_KEY"]
8 respan_base_url = os.getenv("RESPAN_BASE_URL", "https://api.respan.ai/api")
9 
10 async def main():
11     options = ClaudeAgentOptions(
12         model="sonnet",
13         max_turns=1,
14         env={
15             "ANTHROPIC_API_KEY": respan_api_key,
16             "ANTHROPIC_AUTH_TOKEN": respan_api_key,
17             "ANTHROPIC_BASE_URL": f"{respan_base_url}/anthropic/",
18         },
19     )
20 
21     async for message in claude_agent_sdk.query(
22         prompt="Explain tracing in one sentence.",
23         options=options,
24     ):
25         if isinstance(message, ResultMessage):
26             print(message.result)
27 
28 asyncio.run(main())

Switch models

Change the model parameter to use different Claude models through the same gateway.

1 options = ClaudeAgentOptions(model="claude-sonnet-4-5-20250929", ...)
2 options = ClaudeAgentOptions(model="claude-haiku-4-5-20251001", ...)
3 options = ClaudeAgentOptions(model="claude-opus-4-5-20251101", ...)

See the full model list.