Capabilities

Two surfaces, two questions

Docs describe design; the manifest is the runtime truth. Read the service manifest before offering anything optional — email login, claim, private artifacts, cloud PDF, SSO, billing, custom domains, notebooks. When a flag is false, the feature fails closed server-side; skip it gracefully and don't promise it.

The service manifest

curl -sS https://pagelet.link/api/capabilities
{
  "schema": 1,
  "service": {
    "cloud_publish": true,
    "url_scanning": true,
    "cloud_pdf": true,
    "accounts": true,
    "claim": true,
    "web_login": true,
    "password_login": true,
    "sso": { "google": false, "github": false, "microsoft": false },
    "dashboard_mutations": true,
    "mcp": true,
    "live_dashboards": true,
    "versioning": true,
    "pro": false,
    "private_artifacts": true,
    "brand_extract": false,
    "custom_domains": false,
    "notebooks": true
  },
  "runtime": "https://cdn.pagelet.link/v1/",
  "default_expiry_days": 30,
  "abuse_contact": "mailto:abuse@pagelet.link"
}

runtime is the runtime base URL, default_expiry_days the anonymous default (30),abuse_contact where reports go. The same JSON is served by the MCPget_capabilities tool and the pagelet://capabilities resource.

The runtime contract

The capability doc is served next to the runtime and versioned with it — agents fetch it and follow it, so the menu updates server-side with no reinstall. Its front matter is the machine-readable part:

curl -sS https://cdn.pagelet.link/v1/capabilities.md
# ---
# schema: 1
# runtime_version: "0.2.5"
# base_url: "https://cdn.pagelet.link/v1/"
# capabilities: [markdown, mermaid, math, code, charts, theme, toolbar, toc, interactive, versions]
# status: alpha
# ---
# …followed by the full authoring contract for each capability

Each module is lazy-loaded — a page only fetches what it uses. Versioning rule: the rolling/v1/ channel is strictly backward-compatible; immutable exact pins live at/v1.x.y/; a breaking re-architecture would ship as /v2/, so old artifacts never break.

How to feature-detect

1. Before authoring — fetch /v1/capabilities.md for the authoring contract (or rely on the skill, which teaches the same protocol).
2. Before offering a hosted feature — check the matching service.* flag in /api/capabilities. True → proceed; false → deliver locally / skip the offer, and say why.
3. Before promising a link — publish, then fetch the returned URL once and confirm 200 + your HTML. Only then hand it over.
4. Never cache the manifest — it's no-store on purpose; a stale copy advertises features that may have been switched off.