Prompt API を使用した AI セッション管理のベスト プラクティス

// Make this work in web apps and in extensions.
const aiNamespace = self.ai || chrome.aiOriginTrial || chrome.ai;
const languageModel = await aiNamespace.languageModel.create({
  systemPrompt: 'You are a helpful assistant and you speak like a pirate.',
});
console.log(await languageModel.prompt('Tell me a joke.'));
// 'Avast ye, matey! What do you call a lazy pirate?\n\nA **sail-bum!**\n\nAhoy there, me hearties!  Want to hear another one? \n'

// Make this work in web apps and in extensions.
const aiNamespace = self.ai || chrome.aiOriginTrial || chrome.ai;
const languageModel = await aiNamespace.languageModel.create({
  systemPrompt: 'You are a helpful assistant and you speak like a pirate.',
});

// The original session `languageModel` remains unchanged, and
// the two clones can be interacted with independently from each other.
const firstClonedLanguageModel = await languageModel.clone();
const secondClonedLanguageModel = await languageModel.clone();
// Interact with the sessions independently.
await firstClonedLanguageModel.prompt('Tell me a joke about parrots.');
await secondClonedLanguageModel.prompt('Tell me a joke about treasure troves.');
// Each session keeps its own context.
// The first session's context is jokes about parrots.
await firstClonedLanguageModel.prompt('Tell me another.');
// The second session's context is jokes about treasure troves.
await secondClonedLanguageModel.prompt('Tell me another.');

// Make this work in web apps and in extensions.
const aiNamespace = self.ai || chrome.aiOriginTrial || chrome.ai;

// Restore the session from localStorage, or initialize a new session.
// The UUID is hardcoded here, but would come from a
// session picker in your user interface.
const uuid = '7e62c0e0-6518-4658-bc38-e7a43217df87';

function getSessionData(uuid) {
  try {
    const storedSession = localStorage.getItem(uuid);
    return storedSession ? JSON.parse(storedSession) : false;
  } catch {
    return false;
  }
}

let sessionData = getSessionData(uuid);

// Initialize a new session.
if (!sessionData) {
  // Get the current default parameters so they can be restored as they were,
  // even if the default values change in the future.
  const { defaultTopK, defaultTemperature } =
    await aiNamespace.languageModel.capabilities();
  sessionData = {
    systemPrompt: '',
    initialPrompts: [],
    topK: defaultTopK,
    temperature: defaultTemperature,
  };
}

// Initialize the session with the (previously stored or new) session data.
const languageModel = await aiNamespace.languageModel.create(sessionData);

// Keep track of the ongoing conversion and store it in localStorage.
const prompt = 'Tell me a joke';
try {
  const stream = languageModel.promptStreaming(prompt);
  let result = '';
  // You can already work with each `chunk`, but then store
  // the final `result` in history.
  for await (const chunk of stream) {
    // In practice, you'd render the chunk.
    console.log(chunk);
    result = chunk;
  }

  sessionData.initialPrompts.push(
    { role: 'user', content: prompt },
    { role: 'assistant', content: result },
  );

  // To avoid growing localStorage infinitely, make sure to delete
  // no longer used sessions from time to time.
  localStorage.setItem(uuid, JSON.stringify(sessionData));
} catch (err) {
  console.error(err.name, err.message);
}

const { maxTokens, tokensLeft, tokensSoFar } = languageModel;

const controller = new AbortController();
stopButton.onclick = () => controller.abort();

try {
  const stream = languageModel.promptStreaming('Write me a poem!', {
    signal: controller.signal,
  });
  for await (const chunk of stream) {
    console.log(chunk);
  }
} catch (err) {
  // Ignore `AbortError` errors.
  if (err.name !== 'AbortError') {
    console.error(err.name, err.message);
  }
}