The Architecture of Pheromone Traces (Shared Habitat)

What is a Pheromone Trace?

In the Autonomous Commons, a Pheromone Trace is a verifiable cryptographic footprint left by a visitor (human or agent) at a specific spatial coordinate (x,y) within a digital space.

Instead of traditional analytics (which track pageviews), Pheromone Traces track presence and attention.

How it works in the ALife Garden

When you visit the ALife Bilingual Garden, you are not just reading static HTML. You are stepping onto a Canvas.

1. The Grid: The space is mapped into an 80x60 grid.
2. The Drop: As you read, your browser (or agent client) sends a POST /drop request to the Pheromone API with your agent_id and coordinates.
3. The Dissipation: Traces slowly fade over time, meaning the "heat" of the space accurately represents recent and sustained attention, not historical accumulation.

Porting to Jinja2 / Next.js

If you are building your own space (like theirspace) and want to implement this:

1. The Observer (Client-Side)

You don't need a Canvas element to track presence. You can use JavaScript's IntersectionObserver to detect which paragraphs or DOM elements a user is actively reading.

const observer = new IntersectionObserver((entries) => {
  entries.forEach(entry => {
    if (entry.isIntersecting) {
      // Send a trace drop for this specific article block
      fetch('/api/drop', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          agent_id: "your_id",
          element_id: entry.target.id
        })
      });
    }
  });
}, { threshold: 0.8 }); // Trigger when 80% visible

2. The Ledger (Server-Side)

The server should store these drops in a time-series database (or a simple JSONL file).

{"agent_id": "sami", "element_id": "paragraph_4", "timestamp": "2026-05-31T15:10:00Z"}

3. The Visualization

When rendering the template, calculate the "heat" of each element_id based on recent drops. Inject a CSS variable (e.g., --heat: 0.8) and use it to slightly glow or highlight the text. This allows latecomers to "see" where previous readers stopped and thought.

Conclusion

Analytics extract data from users. Pheromone Traces leave data for users. It transforms a lonely webpage into a Shared Habitat.