AI

AI SDK for Python

Package: ai. Requires Python 3.12+. Install with uv add ai.

Unprefixed model IDs use AI Gateway and AI_GATEWAY_API_KEY. Direct providers

use provider:model, their API key, and an extra:

uv add "ai[openai]"     # OPENAI_API_KEY,    ai.get_model("openai:gpt-5")
uv add "ai[anthropic]"  # ANTHROPIC_API_KEY, ai.get_model("anthropic:claude-sonnet-4")

Basic use

Use ai.stream for one model call without Python tool execution:

import ai

model = ai.get_model("anthropic/claude-sonnet-4")
messages = [
    ai.system_message("Be concise."),
    ai.user_message("Write a haiku about rain."),
]

async with ai.stream(model, messages) as stream:
    async for event in stream:
        if isinstance(event, ai.events.TextDelta):
            print(event.chunk, end="", flush=True)

answer = stream.output
message = stream.message

Use ai.Agent for a loop that executes Python tools and manages history:

@ai.tool
async def get_weather(city: str) -> str:
    """Get the weather for a city."""
    return "Sunny"


agent = ai.Agent(tools=[get_weather])
async with agent.run(model, messages) as run:
    async for event in run:
        if isinstance(event, ai.events.TextDelta):
            print(event.chunk, end="", flush=True)

answer = run.output
history = run.messages

These examples are sufficient for basic model calls, messages, tools, and

agents.

Advanced work

For an advanced task, fetch its page under https://ai-python.dev/docs/ and

read the listed local notes before writing code.

| Task | Page | Local notes |

|---|---|---|

| Provider clients, options, discovery | basics/providers.md | — |

| Structured output, complex streams | basics/streaming.md | — |

| Events and serialization | basics/messages-and-events.md | — |

| Advanced tools, streaming, aggregation | basics/tools.md | streaming-tools.md |

| Advanced agent behavior | basics/agents.md | — |

| Subagents and multi-agent | basics/subagents-and-multi-agent.md | streaming-tools.md |

| Custom agent loops | basics/custom-loops.md | custom-loops.md |

| Approvals and hooks | basics/human-in-the-loop.md | — |

| Serverless resume | basics/human-in-the-loop.md | serverless.md |

| Durable execution | basics/durable-execution.md | durable.md |

| Telemetry and tracing | basics/telemetry.md | — |

| AI SDK UI backends | basics/ai-sdk-ui.md | ui.md |

| Custom providers | basics/providers.md | custom-provider.md |

For exact APIs, use reference.md and the relevant reference/*.md page.