Environment Variables

DOWNCITY_CITY_ADMIN_SECRET_KEY, DOWNCITY_CITY_TOKEN_SIGNING_KEY, and BETTER_AUTH_SECRET are generated automatically on first boot and stored in City's env table. Provider API keys should be written into the same table through the Admin API or Studio CLI.

If DOWNCITY_CITY_DATABASE_URL is omitted, the default database path is:

.base/downcity.sqlite

How provider env is used

The model handler reads directly from ctx.env:

const deepseek = new Provider("deepseek", {
  env: { DEEPSEEK_API_KEY: "DeepSeek API Key" },
  envKey: "DEEPSEEK_API_KEY",
  text: async (ctx) => {
    const apiKey = ctx.env("DEEPSEEK_API_KEY");
    const { createOpenAI } = await import("@ai-sdk/openai");
    const client = createOpenAI({
      apiKey,
      baseURL: "https://api.deepseek.com",
    });
    const result = await generateText({
      model: client.chat("deepseek-v4-flash"),
      prompt: ctx.input.prompt,
    });
    return assistantMessage(result.text, ctx);
  },
  stream: async (ctx) => { /* ... */ },
});

So the practical rules are simple:

• you choose the env key names yourself
• uppercase snake case is recommended
• read values through ctx.env(key) inside the handler

Write values into the database

A trusted backend can write provider keys through AdminClient:

await admin.env.upsert({
  key: "DEEPSEEK_API_KEY",
  value: "sk-xxx",
});

These values are stored in the env table inside the City database. Business runtime reads only from that City-managed env table and no longer falls back to .env or process environment variables.

See also Provider environment variables.