AIChannel Environment Variables — Downcity City SDK Docs

Declare the key on the Channel:

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

  protected async stream(input: AIChannelStreamInput) {
    const api_key = input.env("DEEPSEEK_API_KEY");
    if (!api_key) throw new Error("DEEPSEEK_API_KEY is required");
    return stream_openai_compatible_model(input, {
      api_key,
      base_url: this.base_url ?? "https://api.deepseek.com/v1",
    });
  }
}

env declares the variables shown in the model catalog's admin view. Add multiple entries when a Channel needs more than one value.

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