Access & Roles

Roles are composed, never hardcoded. Atomic permissions compose into roles; roles gate data down to row and column, and decide which module interfaces a build even sees. It replaces the client/server key split: a credential names an identity, its roles resolve per request.

When to use it

You need a credential narrower than "client" or "server": composed roles resolve behind it per request.
Data access must stop at rows and columns: region scoping, PII masks, read-only contractors.
A build should only see the interfaces its role unlocks: kick and close aren't there for a visitor at all.
Your UI must grey out buttons accurately: CanI evaluates the same policy the server will enforce.
Skip it when the shipped presets (player, room-owner, seller, …) already match your actors. Every module respects them by default; the full catalogue is on Core Concepts.

Who does what

Actor	On this page
`operator`	declares roles and policies, sets row/column limits, grants roles, issues keys
`match-organizer`	tournament staff: holds a composed key, gates entries, cannot refund
`every actor`	checks `CanI` before acting; sees only its unlocked interfaces

At a glance

Declare entry-validator with row/column limits, grant it, then check CanI before acting

[Role("entry-validator")]
public class EntryValidator
{
    [Allow(Rooms.Membership.Administer)] public Permit GateEntries;
    [Allow(Data.Records.Read, table: "player_profile", rows: "banned == false",
           columns: "id, display_name")] public Permit SeeProfiles;
}

await PlayServ.Access.Grant(staffId, Roles.EntryValidator, Roles.MatchOrganizer);
var key = await PlayServ.Access.IssueKey(staffId);   // the credential names no roles

// any actor, before attempting an operation:
if (await PlayServ.Access.CanI(Commerce.Orders.Administer)) Hud.ShowRefund();

@Role('entry-validator')
export class EntryValidator {
  @Allow(Rooms.membership.administer) gateEntries: Permit;
  @Allow(Data.records.read, { table: 'player_profile', rows: 'banned == false',
                              columns: ['id', 'display_name'] }) seeProfiles: Permit;
}

await playserv.access.grant(staffId, Roles.entryValidator, Roles.matchOrganizer);
const key = await playserv.access.issueKey(staffId);  // the credential names no roles

// any actor, before attempting an operation:
if (await playserv.access.canI(Commerce.orders.administer)) hud.showRefund();

@role("entry-validator")
class EntryValidator:
    gate_entries = allow(rooms.membership.administer)
    see_profiles = allow(data.records.read, table="player_profile",
                         rows="banned == false", columns=["id", "display_name"])

await playserv.access.grant(staff_id, roles.ENTRY_VALIDATOR, roles.MATCH_ORGANIZER)
key = await playserv.access.issue_key(staff_id)   # the credential names no roles

# any actor, before attempting an operation:
if await playserv.access.can_i(commerce.orders.administer):
    hud.show_refund()

Coming soon — Go

Attribute-style declaration in Go is still open (O-1) — the samples land when the carrier is decided.

// declarations compile into the same pushed model — playserv push from the UE project or CI
USTRUCT(PSRole = "entry-validator")
struct FEntryValidator
{
    GENERATED_BODY()

    UPROPERTY(PSAllow = (Atom = "Rooms.Membership.Administer"))
    FPSPermit GateEntries;

    UPROPERTY(PSAllow = (Atom = "Data.Records.Read", Table = "player_profile",
                         Rows = "banned == false", Columns = "id, display_name"))
    FPSPermit SeeProfiles;
};

// granting is an operator act; a build checks what its identity resolves to
const FPSActor Me = Client->Whoami();   // which interfaces this actor unlocks
Client->Access->CanI(TEXT("Commerce.Orders.Administer"),
    TPSOnResult<bool>::CreateWeakLambda(this, [this](const TPSResult<bool>& Result)
    {
        if (!Result.HasValue()) { return; }
        if (Result.Value()) { Hud->ShowRefund(); }
    }));
// co_await support ships later: a built-in SDK coroutine wrapper that respects Unreal's GC and threading.

// the same `[Role]` / `[Allow]` declaration as the server tab, on the Unity 2021.3 runtime
var me = playserv.Whoami();               // which interfaces this actor unlocks
if (await playserv.Access.CanI(Commerce.Orders.Administer)) hud.ShowRefund();

An atom is a pair — a resource and one of four verbs: read, write, execute, administer. The verb set is fixed, and a case that does not fit splits the resource instead of growing the list. That is why gating somebody else's entry is Rooms.Membership.Administer rather than a ValidateEntry verb of its own: acting on another actor's membership is administration, while joining yourself is Rooms.Membership.Write on the same resource.

The model

The data ACL is role × operation × row predicate × field mask — one model, identical whether it was authored in code, through the API, or in the panel's role grid.

What access is built from.

Term	What it is
`atom`	one resource × verb pair. The four verbs are `read` (fetching, selecting, subscribing), `write` (creating, changing, deleting, and acting for oneself — join, leave), `execute` (invoking a function, applying an ability) and `administer` (acting upon others: kick, close, force a state change)
`role`	a named set of atoms. It may include another role
`role preset`	ships over atoms and keeps working unchanged for already-deployed consumers. A starting point, not a constraint: a project declares roles of its own out of the same atoms
`row predicate`	which rows — a boolean predicate over session values
`field mask`	which fields, declared per role and operation

What a credential resolves to.

Credential	What it unlocks
`player key`	an engine build carries it; the player behind it arrives with sign-in, and the build sees the `cl` rows of every operations table
`host key`	a dedicated server or a master-client holds it, and its roles unlock the `mc` rows
`pushed code`	runs as the project's `backend-service` role — that is what a leaderboard's `Authoritative = true` checks
`a registered hook`	grants nothing extra: your function keeps the role it deployed under

The tag legend (fn / cl / mc / adm) is owned by Core Concepts.

What is true of every check.

Always	What it is
`a credential`	carries no role list: it names an identity, and roles resolve server-side per request. A revocation invalidates the cached resolution at once rather than waiting out its declared staleness bound
`delegation`	changes scope, never capability: acting on behalf of a player changes which rows are visible and to whom a write is attributed, and grants no operation the actor did not already hold
`the verb`	answers what kind of effect, and the predicate answers which rows. If two cases differ only in whose row it is, that is a predicate; if the effect itself differs, that is another operation and possibly another verb — which is why "kick" is `administer` rather than `write` with a wide predicate
`an owner`	always sees itself, whatever else a predicate says
`visibility`	is not security — a channel optimisation and a permission are different mechanisms, and neither substitutes for the other
`a disabled module`	has no surface: whether a module is enabled is a property of the build, so codegen emits nothing for a disabled one and an unavailable call is a compile error rather than a runtime refusal
`a module's surface`	follows the actor rather than the side (see Authority): a `room-visitor` build sees join, leave and read, a `room-owner` build additionally sees kick, close and configure, and `whoami` reports which interfaces the current actor unlocks

Who hands out a role. Granting and revoking a role to a player, and the project's declared default role for a new one, are operations on Auth & Players — that module owns identities, and a role is resolved by the identity in the credential.

Errors

What a predicate hides answers not found, not forbidden : otherwise the refusal itself would tell the caller that the thing exists.
A right the caller does not hold answers forbidden where the subject's existence is not a secret, and it names what was missing rather than failing blankly.
A field outside the mask is absent from the answer, not present and empty: an empty value and a masked one would be indistinguishable.
A role including itself, directly or through a chain, is a configuration error — refused as a declaration rather than resolved at runtime.
Delegation never widens capability: a call the actor could not make on its own behalf is refused when made on a player's.

Limits

The numbers arrive with the platform limits chapter; what happens at each ceiling is fixed now.

The size of a selection under a row predicate is bounded, and the ACL model declares that bound rather than discovering it. A read above the ceiling is answered with the ceiling's worth of rows plus the marker saying it was cut, never with a silent short page.
The staleness bound of a resolved permission is declared, and a revocation does not wait it out — it invalidates at once.