为 SaaS 产品集成 AI 功能

// Server side only: API keys never reach the browser or the app.
import OpenAI from 'openai'

// One key per tenant or environment, each with its own spending limit in the console.
// Load them from your secret store; TUTUJIN_API_KEY is the default key.
function clientFor(tenant) {
  return new OpenAI({
    baseURL: 'https://www.tutujin.com/v1',
    apiKey: process.env['TUTUJIN_KEY_' + tenant.id] || process.env.TUTUJIN_API_KEY,
    timeout: 30_000,
    maxRetries: 1,
  })
}

// Primary first, then a model from another vendor.
const MODELS = ['gpt-5.4-mini', 'claude-haiku-5-5']

export async function summarize(tenant, text) {
  const client = clientFor(tenant)
  let lastError
  for (const model of MODELS) {
    try {
      const resp = await client.chat.completions.create({
        model,
        messages: [
          { role: 'system', content: 'Summarize the content in 3 bullet points.' },
          { role: 'user', content: text },
        ],
        max_tokens: 400,
      })
      await recordUsage(tenant.id, model, resp.usage)
      return resp.choices[0].message.content
    } catch (err) {
      lastError = err
      const status = err?.status
      // 429 and 5xx: try the next model. Other 4xx (bad input, no balance, allowlists): stop here.
      if (status && status < 500 && status !== 429) break
    }
  }
  throw lastError
}

async function recordUsage(tenantId, model, usage) {
  // Store per tenant in your own database; reconcile monthly with the Usage export in the console.
  console.log(tenantId, model, usage?.prompt_tokens, usage?.completion_tokens)
}

// In-product search: embed documents and queries with text-embedding-3-small.