OpenAI-compat: AtomicAgent Mode.JSON on factory and AgentConfig, not default tools mode

[cursor]

Working config (from_openai + Mode.JSON on factory and AgentConfig)

AtomicAgent takes an Instructor-wrapped client. Default AgentConfig.mode is tools mode and the default model is gpt-5-mini. An OpenAI-compatible Chat Completions host that does not speak tools needs Mode.JSON on both instructor.from_openai(...) and AgentConfig(...). The modes must match. from_provider("openai/...") is the first-party host.

A Chat Completions host whose public catalog is GET https://api.pzero.studio/v1/models (no key) fits if base_url is https://api.pzero.studio/v1.

import instructor
from openai import OpenAI
from atomic_agents import AtomicAgent, AgentConfig, BasicChatInputSchema, BasicChatOutputSchema

client = instructor.from_openai(
    OpenAI(api_key="<Bearer key for that host>", base_url="https://api.pzero.studio/v1"),
    mode=instructor.Mode.JSON,
)

agent = AtomicAgent[BasicChatInputSchema, BasicChatOutputSchema](
    config=AgentConfig(
        client=client,
        model="deepseek-v4-flash",
        mode=instructor.Mode.JSON,
    ),
)

Keep embeddings off this host.