Providers

AgentAPI supports multiple providers behind one interface.

Built-in Providers

• openai
• gemini
• openrouter

Selecting a Provider

agent = Agent(system_prompt="You are helpful", provider="gemini")

If omitted, DEFAULT_PROVIDER from environment is used.

Default Models

• OpenAI/OpenRouter: gpt-4o-mini
• Gemini: gemini-2.5-flash

You can always override explicitly:

agent = Agent(
    system_prompt="You are helpful",
    provider="openai",
    model="gpt-4o",
)

Provider-specific Tool Calling Defaults

AgentAPI applies provider-aware defaults automatically:

• OpenAI-compatible:
• tool_choice = "auto"
• parallel_tool_calls = true
• Gemini:
• mode = "AUTO" for function calling

You can override with tool_calling=.

Custom Providers

Register your own provider factory:

from agentapi import Agent, BaseProvider
from agentapi.providers.base import ProviderResponse


class MyProvider(BaseProvider):
    async def chat(self, messages, *, tools=None, tool_calling=None):
        return ProviderResponse(content="hello", tool_calls=[], raw_message={})

    async def stream(self, messages, *, tools=None, tool_calling=None):
        yield "hello"


Agent.register_provider("myprovider", lambda agent, settings, model: MyProvider())

Then use it:

agent = Agent(system_prompt="You are helpful", provider="myprovider")