Environment Variables

examples/14-env-vars.halo policies

How to use Env.* to access environment variables WHY: API keys and config should come from environment

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// ============================================================
// STEP 14: Environment Variables
// ============================================================
// LEARN: How to use Env.* to access environment variables
// WHY:  API keys and config should come from environment
// ============================================================

// Define tools that use environment variables for API keys
tool StripeAPI : REST("api.stripe.com/v1", apiKey: Env.STRIPE_KEY)
tool SlackBot  : POST("hooks.slack.com/services/alerts", apiKey: Env.SLACK_TOKEN)
tool VectorDB  : VectorStore(Env.PINECONE_KEY, namespace: "production")

policy Privacy : Redact(SalaryData) & Redact(Revenue)

// Agent that uses environment for API key
agent Analyst [openai/gpt-4o, temp: 0.3]
  equips StripeAPI, VectorDB
  requires Privacy

pipeline DailyReport(date: String) -> Result:
  date
    // Tool calls automatically use Env.* keys at runtime
    |> Analyst.fetch_metric(
        tool: StripeAPI,
        metric: "mrr",
        date: context.input.date
      )
    |> System.Print()

// At runtime, set environment variables:
//   export STRIPE_KEY="sk_live_..."
//   export SLACK_TOKEN="xoxb-..."
//   export PINECONE_KEY="pc-..."