Sharing — Private by Default, Explicit Share

Rule

Any resource a user creates (dashboards, documents, forms, decks, compositions, booking links, issues, analyses) is private to the creator by default and visible to others only when they have been explicitly shared with or when the creator changes visibility to org or public.

This is the framework-level primitive. Every ownable resource gets it for free — same API, same UI, same skill.

Concepts

Three visibility levels

• private — owner + explicit share grants only. Default.
• org — owner + explicit grants + anyone in the same org (read-only).
• public — owner + explicit grants + anyone with the link (read-only). Public docs do NOT appear in other users' list/sidebar/search results — accessFilter omits them by default. They're reachable by id (resolveAccess admits them) so direct links and SSR routes like /p/:id keep working. If a list endpoint legitimately needs cross-user public discovery (a template gallery, etc.), pass accessFilter(table, shares, ctx, minRole, { includePublic: true }).

Visibility is coarse. Explicit share grants are fine-grained (per user or per org).

Roles on a share grant

• viewer — read only.
• editor — read + write.
• admin — read + write + manage shares. Does NOT replace the single owner_email on the resource.

Anonymous public URLs stay separate

Form "publish" slugs, booking-link slugs, any feature that exposes a URL to unauthenticated users — these are a different axis and are NOT controlled by the sharing system. Keep them alongside it.

Make a resource ownable

In your template's server/db/schema.ts:

import {
  table,
  text,
  integer,
  now,
  ownableColumns,
  createSharesTable,
} from "@agent-native/core/db/schema";

export const decks = table("decks", {
  id: text("id").primaryKey(),
  title: text("title").notNull(),
  data: text("data").notNull(),
  createdAt: text("created_at").notNull().default(now()),
  updatedAt: text("updated_at").notNull().default(now()),
  ...ownableColumns(), // adds owner_email, org_id, visibility
});

export const deckShares = createSharesTable("deck_shares");

Then register it in server/db/index.ts (not the schema file — keeps the schema file free of the getDb closure and avoids circular imports):

// server/db/index.ts
import * as schema from "./schema.js";
import { createGetDb } from "@agent-native/core/db";
import { registerShareableResource } from "@agent-native/core/sharing";

export const getDb = createGetDb(schema);
export { schema };

registerShareableResource({
  type: "deck",
  resourceTable: schema.decks,
  sharesTable: schema.deckShares,
  displayName: "Deck",
  titleColumn: "title",
  getResourcePath: (deck) => `/deck/${deck.id}`,
  getDb,
});

The type string is the stable id the UI and actions use. getDb is required — the framework-level share actions use it to reach your template's DB.

Restricting public visibility and cross-org user shares

Some resources should NOT be reachable by an arbitrary authenticated user even with the link, and should NOT be shareable to an email outside the org. Two optional registration flags lock these axes down:

registerShareableResource({
  type: "extension",
  // ...
  allowPublic: false, // hides "Public" in the share dialog and rejects it server-side
  requireOrgMemberForUserShares: true, // user shares must target an org member or pending invitee
});

• allowPublic: false — set-resource-visibility('public') throws ForbiddenError, accessFilter / resolveAccess treat any stored 'public' row as private (defense in depth against bad data), and the share popover hides the "Public" option. list-resource-shares returns policy.allowPublic: false so the UI follows the server.
• requireOrgMemberForUserShares: true — share-resource looks up principalId in org_members and org_invitations (pending) for the resource's orgId and rejects user shares to anyone else. The same flag also pins principalType: "org" shares to the resource's own org — sharing to a different org would let that org's members run code in the viewer's auth context (same threat model as a public extension). (The flag name is kept for backward compatibility; treat it as "lock both user and org shares to the resource's org".)

Use both for resources that execute code or expose privileged data with the viewer's credentials. Extensions ship with both set: an extension's HTML calls actions / SQL / the secrets-injecting proxy as the viewer, so a public or cross-org-shared extension would let a stranger run arbitrary code with someone else's auth context. scripts/guard-extension-no-public.mjs (CI + pnpm prep) statically enforces that the extension registration keeps both flags set.

Defaults match historical behaviour: allowPublic: true, requireOrgMemberForUserShares: false. Resources that don't set the flags work as before.

Filter list/read queries

import { accessFilter } from "@agent-native/core/sharing";

const rows = await db
  .select()
  .from(schema.decks)
  .where(accessFilter(schema.decks, schema.deckShares));

accessFilter admits rows the current user owns, has been shared on, or that the user can reach via org visibility. public rows are NOT admitted by default — see the visibility section above for why and how to opt in.

Guard write actions

import { assertAccess } from "@agent-native/core/sharing";

export default defineAction({
  schema: z.object({ id: z.string(), title: z.string() }),
  run: async (args) => {
    await assertAccess("deck", args.id, "editor");
    // ...proceed
  },
});

For delete actions use "admin" (or fold in "owner" to require the real owner).

Create actions must set owner

When inserting a new row, fill ownerEmail and orgId from the request context:

import {
  getRequestUserEmail,
  getRequestOrgId,
} from "@agent-native/core/server/request-context";

const ownerEmail = getRequestUserEmail();
// Never fall back to a sentinel like "local@localhost" — that pools every
// unauthenticated write into one shared tenant (see the 2026-04-29 leak and
// guard-no-localhost-fallback). Throw / 401 when there is no session instead.
if (!ownerEmail) throw new Error("Not authenticated");

await db.insert(schema.decks).values({
  id: nanoid(),
  title,
  data,
  ownerEmail,
  orgId: getRequestOrgId(),
  // visibility defaults to 'private'
  // ...
});

Drop in the share UI

import { ShareButton } from "@agent-native/core/client/sharing";

// In the resource's header/toolbar:
<ShareButton
  resourceType="deck"
  resourceId={deck.id}
  resourceTitle={deck.title}
/>;

For list views, show <VisibilityBadge visibility={row.visibility} /> next to each resource.

Actions available everywhere

The framework auto-mounts these actions in every template — no per-template boilerplate:

Both the agent and the UI use these same actions. The agent calls them as tools; UI code should use ShareButton / ShareDialog or the action client hooks instead of hand-writing route calls.

Migration pattern for existing tables

When retrofitting an existing resource table:

1. Add owner_email, org_id, visibility columns (defaults 'local@localhost', NULL, 'private').
2. Backfill owner_email from any prior creator trail; otherwise leave the default.
3. Add the companion {type}_shares table.
4. Register via registerShareableResource.
5. Update list/read actions to use accessFilter.
6. Update update/delete actions to assertAccess with the correct role.
7. Add <ShareButton> to the resource header.
8. Add getResourcePath in the registration so agent-triggered shares can email a direct link even when no UI supplied resourceUrl.

Templates that opt out

Sharing doesn't apply to:

• Personal-data apps (mail, macros) — user-scoped by design.
• External source-of-truth apps (issues → Jira, recruiting → Greenhouse) — ACL lives in the upstream system.
• Demo/boilerplate (starter) — no resources.

For these, add a short note to the template's AGENTS.md explaining why.

Analytics (follow-up)

Dashboards and analyses in the analytics template currently live in the settings KV store (u:<email>:dashboard-* keys), not SQL. Sharing requires either migrating them to SQL tables (then applying this skill) or extending the settings store with a parallel share overlay. This is a tracked follow-up — see the analytics template's AGENTS.md.

Debugging

• ForbiddenError from an action means the current user isn't owner / hasn't been shared / can't meet the role bar.
• If the agent can't see a resource it just created, check that the insert actually set owner_email from the request context.
• If a share doesn't take effect in the UI, confirm the template's list-* action uses accessFilter — the share rows are there but nothing is reading them yet.