# `@suaveplan/api-auth-anonymous` — Null-principal session resolver

**Package**: `@suaveplan/api-auth-anonymous`
**Status**: PROPOSED
**Type**: new-package
**Stage**: 4 (Base adapters) — see umbrella `openspec/changes/api-plugin-foundation/`

## Why

Per design doc §2.3, every API host MUST configure a session resolver — even fully public APIs. `api-auth-anonymous` is the trivial session resolver that always returns `null`. Configuring it explicitly makes the "no auth" choice visible in `host.json` and lets the rest of the host (RBAC gate, error envelope, OpenAPI) operate uniformly: the principal is simply `null`, never undefined.

Stage 4 invariant: both direct and worker-proxy surfaces ship and pass `runAuthSessionConformance` (§5.2a, §13.4). The proxy is trivial here (no network/state) but its presence keeps the adapter table uniform — every adapter has both surfaces, no exceptions.

## What changes

Net-new package depending on `@suaveplan/api-auth`, `@suaveplan/api-types`, `@suaveplan/api-worker-rpc`.

- ADDED: `createAnonymousSessionResolver()` — direct-surface factory returning an `AuthAdapter` whose `resolveSession` always returns `null`.
- ADDED: `createAnonymousSessionResolverWorkerProxy(port)` — proxy-surface factory.
- ADDED: `securitySchemeContribution()` — returns an empty OpenAPI `securitySchemes` block. Routes without `publicRoutes` declaration still emit the host's default security entry list (which is empty for anonymous).
- ADDED: `AnonymousResolverOptions` — currently empty; reserved for future flags (e.g. `logAnonymousAccess: boolean`).

## Out of scope

- Policy on whether a route requires auth — the host enforces `publicRoutes` from each plugin's manifest; this resolver only ever supplies `null`.
- Rate limiting based on IP / fingerprint — `api-rate-limit` Stage 8.

## Source mapping

Genesis-original. Source of design intent: `docs/superpowers/specs/2026-05-13-api-plugin-foundation-design.md`.

| Requirement | Design doc section |
|---|---|
| Always returns null principal | §2.3 (`api-auth-anonymous` bullet) |
| Worker-proxy variant required | §5.2a |
| Conformance both surfaces | §13.4 |

## Verification approach

- `src/factory/create-anonymous-session-resolver.test.ts` — direct surface always returns null.
- `src/factory/create-anonymous-session-resolver.spec-conformance.test.ts` — `runAuthSessionConformance("anonymous-direct", ...)` (the suite must accept resolvers that always return null).
- `src/proxy/create-anonymous-session-resolver-worker-proxy.test.ts` — proxy unit tests.
- `src/proxy/create-anonymous-session-resolver-worker-proxy.spec-conformance.test.ts` — `runAuthSessionConformance("anonymous-worker-proxy", ...)`.

## Migration impact

None — additive only.