Quickstart
From an account to a card on a live page, on a Cloudflare Worker.
How it works
- A visitor, human or AI agent, requests a page. Your edge reads its
User-Agent. - For an AI agent, your edge calls
GET /v1/fragmentwith the page URL. doubleshift answers with a card (200) or, when nothing is eligible, a no-fill (204). - Your edge places the card right before the article content. If the call is slow, fails, or returns a no-fill, it serves the page without a card.
- A human gets the page unchanged, and doubleshift is never called.
Only AI agents trigger a card from GET /v1/fragment; humans get the page unchanged.
What ABC is not
- Not a paywall, and not a licensing deal. The agent still reads the page in full; the card sits alongside it.
- Not a change to the human page. Humans never receive a card.
- Not client-side. The card is placed at your edge, server-side. No script runs in a browser.
- Not a guarantee of citation. A card puts branded context in front of an agent; what the agent does with it is not something any provider can promise.
Sites, fragments and cards
Next steps
Other edges
Vercel / Next.js or ESI, and the rules every edge keeps.
Set up cards
Create a card and choose the fragments it may serve on.
Read the reporting
What the console counts: served calls, by agent, fragment and card.
API reference
The delivery API, the card format, the agent list and the edge library.
Automate setup with the management API
Optional: set up sites, fragments and eligibility from a script.

