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Cookbook

Cookbook

The repository ships a complete host in cookbook/ — two files, in memory, nothing to configure:

cd cookbook
bun install
bun run server.ts     # → http://localhost:8787
the example admin UI, generated from the descriptor The cookbook host: the browser UI reads the descriptor and the admin routes from server.ts, which owns the in-memory store and a check probe

server.ts declares a five-action vocabulary with derivation (articles.publish → articles.write → articles.read), two condition keys, two seeded curated policies, and mounts the admin handlers plus a /api/check probe. The in-memory store is the instructive part: it implements AdminStore, GrantStore and AuditSink in about a hundred lines, which is the entire surface a real backend needs — swap it for PgAuthzStore and nothing else changes.

ui.html is a complete admin UI in one static file with no host knowledge: every control renders from the descriptor, exactly as Building a UI describes — the version gate, the generated bounds form, the coverage panel, set-operator switching, and the engine’s validation messages surfaced verbatim.

The in-memory store

Storage & conformance points here for a reason: MemoryAdminStore in cookbook/server.ts is a complete non-Postgres backend — AdminStore, GrantStore and AuditSink in about a hundred lines. The shape of it:

class MemoryAdminStore implements AdminStore {
  // the admin surface
  async listPolicies(): Promise<PolicyRecord[]> { … }
  async listGrants(filter): Promise<GrantRecord[]> { … }
  async createGrant(input): Promise<void> { … }        // replaces bounds on re-grant
  async deleteGrant(id): Promise<boolean> { … }
  async listAudit(opts): Promise<AdminAuditRecord[]> { … }

  // the evaluation seam (GrantSource): EXACTLY the grants whose
  // subject AND scope match — the engine unions what it is given
  async grantsFor(subjects, chain): Promise<ResolvedGrant[]> { … }

  // the audit sink — fire-and-forget from the engine's point of view
  record(event: AuditEvent): void { … }
}

Swap it for PgAuthzStore — or your own — and nothing else in the host changes. To prove a real replacement, run the conformance fixtures through it as Storage & conformance shows.

What to try

DoSee
grant article-author to alice bounded to app:Region = eu-west, probe in and out of regionthe bound withdraws the allow — but only the allow
probe alice against billing.readthe policy’s own deny stands, bounds or not
probe articles.publishcovered via derivation — the coverage panel named it before you saved
submit a bound with a wrong operatorcondition 0: NumericLessThan cannot test app:Region (a string key) — the engine’s words
add a condition key in server.ts, restarta new form field appears with zero changes to ui.html

That last row is the reuse test the descriptor exists to pass: if adding a key server-side does not produce a new field with no frontend change, the descriptor is not doing its job.

MCP serverStorage & conformance