Actor envelope contract

The actor.* fields are the single source of authorization input to the DSL. Every policy, spec, query filter, or mutation body that gates on the authenticated actor MUST read through the envelope; nothing in the engine should reach around it.

#What the envelope is

When a request hits the gRPC stream, the auth interceptor (component/grpc/auth_session_middleware.go) validates the JWT (or the API-key bearer / Worker token, per the identity shape) and builds an auth.Identity struct. The engine binds that identity onto the request context; resolver code reads it back via auth.UserIdentityFromContext.

The DSL surface is read-only access to that same identity through dotted-path fields on the actor namespace. Author-side:

@actor
shape actorEnvelope {
  actor.userId
  actor.role
  actor.identityId
  actor.isClusterOwner
  actor.now
}

Engine-side, dotted paths route through component/memql/executor.go:resolveActorReferences (line 377) → resolveActorPath (line 427), matching each *ActorReference node (line 383) against the resolved envelope. #221 renamed both the DSL surface and these internal Go names, so actor. is the vocabulary top to bottom -- there is no leftover caller. / CallerReference naming behind it.

#Field reference

(The pre-#56 envelope also exposed actor.partitions + actor.partition. Those are retired and the parser rejects them with a migration hint -- partitioning came out in #56 phase 5.)

#Identity shapes

The envelope exposes the same field names regardless of how the caller authenticated, but the underlying behavior differs:

The auth interceptor (component/grpc/auth_session_middleware.go)

• the worker interceptor (worker_stream_interceptor.go) builds the right envelope based on which token shape arrived. The engine never re-classifies; it just reads through the envelope.

#What the envelope is NOT

• Not a permission set. The envelope says who the actor is, not what they can do. The DSL composes permissions on top of the envelope: policies + specs gate behavior on actor.role, actor.isClusterOwner, actor.userId == payload.ownerUserId, etc.
• Not mutable inside a request. Every field is captured once at request entry. Engine code MUST NOT update the envelope mid-call.
• Not a substitute for storage-level enforcement today. After #56 lands and partitioning went away, the envelope is the only authorization layer.

#Author rules

1. Always read through actor.* -- never inspect auth.Identity directly from Go code that's making an authz decision. (Engine plumbing that constructs the envelope is the sole exception.)
2. @actor shapes carry the binding. Specs that want to gate on actor state bind the shape in their signature (spec actorEnvelope <name> { return <key> }, or a more specific actor shape) and read the projected key bare. The post-load validator catches a binding that resolves to no registered shape.
3. actor.now is the only clock. Never use Go's time.Now() in a DSL evaluator path; that's a source of test-flake + replay-skew.

#Anti-patterns

• Reaching around the envelope for "fast path" reads. Don't read tokenInfo.Subject directly to compose an authz decision -- read actor.userId through the envelope. Today the auth context's Subject and the envelope's userId match; reaching around it lets them silently drift.
• Composing partial envelopes. Don't build a partial actor envelope for a sub-call (e.g. "this query runs as the user but with admin role"). If a privilege escalation is intended, use the delegation concept; otherwise the envelope reflects the authenticated actor exactly as-is.
• Caching the envelope across requests. Per-request only.
• caller.X / @caller. Retired in #221. The parser rejects both spellings; the canonical form is actor.X / @actor.

#Related issues

• #54 — per-row authorization audit (uses the envelope to gate every user-scoped query / mutation)
• #56 — removed partitioning (deleted the partition fields)
• #221 — consolidated caller. / actor. -> actor. for one canonical auth-context vocabulary across the DSL