Page change watcher

# Most ticks are a free diff; the LLM only thinks when the
# page actually changed. Swap the URL/selector for any page you care about.
blueprint:
  id: page-change-watcher
  title: Page change watcher
  description: >-
    Watches a web page and tells you when it meaningfully changes. Most checks
    are free — it only reasons when something on the page is different.
    Ships pointed at the Anthropic newsroom; swap in any page you care about.
config:
  synth:
    name: Page watcher
    goal: Tell me when the page I'm watching meaningfully changes.
    schedule_seconds: 3600
  requires_credentials:
    - WEBHOOK_URL
  sources:
    - id: page
      primitive: dom_scrape
      config:
        url: https://www.anthropic.com/news
        selectors:
          headlines: "h1, h2, h3"
  fast_path:
    primitive: fast_path_diff
    inputs:
      current: $sources.page.headlines
      previous: $state.last_headlines
  reasoning:
    primitive: llm_reason
    triggered_by: fast_path
    model_tier: standard
    budget_usd_per_day: 0.05
    output_schema:
      is_meaningful: bool
      summary: string
      confidence: float
  actions:
    - if: "$reasoning.is_meaningful AND $reasoning.confidence > 0.6"
      primitive: notify_webhook
      config:
        url: $secrets.WEBHOOK_URL
        template: "[Page watcher] {summary}"
    - always: true
      primitive: write_state
      config:
        last_headlines: $sources.page.headlines
        checked_at: $tick.started_at