Entity registry

How to make an ARC model linkable from Brain.

Add a descriptor

1. Open server/src/modules/brain/registry/ and either extend the domain file or add a new one.
2. Call registerEntity({ ... }) with at least entityType, domain, slugPrefix, title, url, fields.
3. If the model has no userId, set resolveUserId (e.g. Day via week).
4. Optional: derivedLinks(row) to project FKs into Link rows with kind = DERIVED.
5. Run pnpm brain:reindex --type=YourModel and confirm GET /api/v1/brain/entities/search?q=….

Template

registerEntity({
  entityType: 'Person',
  domain: 'social',
  icon: 'User',
  color: '#64748b',
  linkable: true,
  autoLink: true,
  slugPrefix: 'person',
  title: (row) => [row.firstName, row.lastName].filter(Boolean).join(' ') || row.name || 'Person',
  subtitle: (row) => row.relationshipType ?? null,
  aliases: (row) => [row.firstName, row.name].filter(Boolean) as string[],
  url: (row) => `/people/${row.id}`,
  fields: {
    firstName: { label: 'First name', type: 'string', editable: true },
    lastName: { label: 'Last name', type: 'string', editable: true },
  },
});

Rules

• If it has an id and a user can open it, it is linkable.
• Indexing is async; a failed index never fails a domain write.
• Soft-delete in the index sets isDeleted = true; rows are not removed so links do not dangle.