会話の途中で推論の度合いを変える

import OpenAI from "openai";

const client = new OpenAI({
	apiKey: process.env.PHASEO_API_KEY,
	baseURL: "https://api.phaseo.app/v1",
});

const messages: OpenAI.ChatCompletionMessageParam[] = [
	{ role: "user", content: "Plan a migration from SQLite to PostgreSQL." },
];

async function ask(effort: "low" | "medium" | "high") {
	const response = await client.chat.completions.create({
		model: "anthropic/claude-opus-5.5",
		reasoning_effort: effort,
		messages,
		// @ts-expect-error Phaseo field: cache the conversation on Claude routes
		cache_control: { type: "ephemeral" },
	});
	const message = response.choices[0].message;
	messages.push(message); // the whole message, reasoning_details included
	return message.content;
}

await ask("high");
messages.push({ role: "user", content: "Summarise the plan in one sentence." });
await ask("low"); // Claude reads request 1 from cache

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["PHASEO_API_KEY"],
    base_url="https://api.phaseo.app/v1",
)

messages = [{"role": "user", "content": "Plan a migration from SQLite to PostgreSQL."}]

def ask(effort: str) -> str | None:
    response = client.chat.completions.create(
        model="anthropic/claude-opus-5.5",
        reasoning_effort=effort,
        messages=messages,
        extra_body={"cache_control": {"type": "ephemeral"}},
    )
    message = response.choices[0].message
    # The whole message, reasoning_details included
    messages.append(message.model_dump(exclude_none=True))
    return message.content

ask("high")
messages.append({"role": "user", "content": "Summarise the plan in one sentence."})
ask("low")  # Claude reads request 1 from cache

import OpenAI from "openai";

const client = new OpenAI({
	apiKey: process.env.PHASEO_API_KEY,
	baseURL: "https://api.phaseo.app/v1",
});

const input: OpenAI.Responses.ResponseInput = [
	{ role: "user", content: "Plan a migration from SQLite to PostgreSQL." },
];

async function ask(effort: "low" | "medium" | "high") {
	const response = await client.responses.create({
		model: "anthropic/claude-opus-5.5",
		reasoning: { effort },
		input,
		// @ts-expect-error Phaseo field: cache the conversation on Claude routes
		cache_control: { type: "ephemeral" },
	});
	input.push(...response.output); // every item, reasoning items included
	return response.output_text;
}

await ask("high");
input.push({ role: "user", content: "Summarise the plan in one sentence." });
await ask("low"); // Claude reads request 1 from cache

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["PHASEO_API_KEY"],
    base_url="https://api.phaseo.app/v1",
)

conversation = [{"role": "user", "content": "Plan a migration from SQLite to PostgreSQL."}]

def ask(effort: str) -> str:
    response = client.responses.create(
        model="anthropic/claude-opus-5.5",
        reasoning={"effort": effort},
        input=conversation,
        extra_body={"cache_control": {"type": "ephemeral"}},
    )
    # Every item, reasoning items included
    conversation.extend(item.model_dump(exclude_none=True) for item in response.output)
    return response.output_text

ask("high")
conversation.append({"role": "user", "content": "Summarise the plan in one sentence."})
ask("low")  # Claude reads request 1 from cache