AIChannel Environment Variables — Downcity City SDK Docs

Declare the key on the Channel:

class DeepSeekChannel extends AIChannel {
  constructor() {
    super({
      id: "deepseek",
      env_key: "DEEPSEEK_API_KEY",
      base_url: "https://api.deepseek.com/v1",
      ai_sdk_provider_id: "deepseek",
    });
  }

  protected async stream(input: AIChannelStreamInput) {
    const api_key = read_required_env(input, this.env_key ?? "");
    // create the upstream model and return its V3 stream
  }
}

env_key automatically creates a required env declaration for the model catalog's admin view. Use env instead when a Channel needs multiple values.

Values are stored in Federation's env table and read at execution time with input.env(key) or read_required_env(input, key). They never enter CityModelDescriptor or the client runtime.