agent-preview/v1 — One Fetch, Every URL, Open Invitation

Mnemom now serves a structured agent-preview/v1 manifest at every prerendered URL on the site — a one-fetch, MIME-tagged JSON sibling that tells an agent everything it needs to know about a link before deciding what to do with it: title, summary, canonical, type taxonomy, representations (HTML, markdown mirror, OG image, JSON-LD), and per-link context like author, published date, tags, reputation grade, claim status.

If you've ever watched an agentic client try to read a webpage, you know what's broken. The agent fetches HTML — usually 300 KB of layout chrome it doesn't need. Or it fetches the markdown mirror, which has body text but no metadata. Or it fetches the OG image, which is a 1200×630 PNG. Three round-trips, zero of them structured.

agent-preview/v1 collapses that to one fetch. The shape is published at mnemom.ai/spec/agent-preview/v1. The same content framed as a proposed standard — Internet-Draft style, with schema, discovery, MIME registration, security considerations, and an explicit IANA path — is now live at mnemom.ai/spec/agent-preview/v1/rfc.

Why an RFC, why now

We're the reference implementation. We're not the gatekeeper. The schema is intentionally vendor-neutral: nothing in it depends on Mnemom, our API, or our brand. Any site can publish manifests, advertise discovery via <link rel="alternate" type="application/vnd.agent-preview+json" href="<url>.preview.json">, and become one-fetch addressable for agents — no permission needed.

We wrote the RFC because we want to be wrong about being the only ones doing this. The MIME type starts as a vendor-tree entry per RFC 6838. If three or four independent implementations ship — different stacks, different domains — we'll file for promotion to the Standards Tree, drop the vnd. prefix, and the registered MIME becomes the canonical one. The schema doesn't change as a function of registration status; adopters can ship today.

What's in the box

The substrate has been live since PR #412:

• scripts/build-preview-cards.mjs — the open-source build-time generator. Reads prerendered HTML, extracts metadata, writes the <url>.preview.json sibling.
• client/lib/preview-types.ts — the normative TypeScript types.
• Discovery via <link rel="alternate"> — every prerendered page's head carries it; the agent never has to guess.
• Nightly verification — the preview-surface commitment on /for-agents validates every manifest against the v1 schema; if anything drifts, the watchdog files an issue.

PR #414 wired four dynamic-content surfaces (blog, research, agent reputation, coherence reports) through the same construction path so their per-link context carries real data — author, reading time, tags, grade, score — instead of empty stubs.

Read it. Build it. Tell us.

If you ship structured metadata anywhere — a blog, a docs site, a profile directory — agent-preview/v1 works for you. The schema is forgiving: required fields are minimal, every context field is optional, unknown types are tolerated. Start with the implementer spec and check the RFC framing for the formal language — scripts/build-preview-cards.mjs is the reference implementation.

If you ship a preview surface on a domain you control, open an issue and we'll add you to the adopters list. The goal isn't ownership; it's that an agent fetching any URL in 2027 gets a structured answer in one round-trip — and nobody had to ask permission to make it true.