Keywords

Bynk reserves names in three tiers. The first two are lexer keywords; the third are compiler-known type names. Only the hard keywords can never be used as an identifier.

Hard keywords

Reserved everywhere — these 60 words can never be used as an identifier.

Keyword	Meaning
Bool	The boolean base type.
Bytes	The binary base type — an immutable octet sequence, erased to Uint8Array (Bytes.fromUtf8(s)).
Duration	The time-span base type, in milliseconds (5.minutes).
Effect	The effectful-computation type, Effect[T].
Err	The error variant of Result.
Float	The floating-point base type.
Instant	The absolute-time base type, in epoch milliseconds (Clock.now()).
Int	The integer base type.
JsonError	The JSON-decode error type, Result[T, JsonError] from Json.decode.
None	The empty variant of Option.
Ok	The success variant of Result.
Option	The optional-value type, Option[T].
Result	The success-or-error type, Result[T, E].
Some	The present variant of Option.
String	The string base type.
ValidationError	The error type returned by a refined type’s .of.
actor	Declare an actor — a boundary contract a handler consumes via by.
adapter	Declare an adapter — the host boundary (capability contract + binding).
agent	Declare a stateful, keyed agent inside a context.
as	Alias a consumed context (consumes X as Y).
binding	Name an adapter’s TypeScript binding module (binding "<module>").
by	Name the actor a handler consumes, after the return type — or a service-level default on the header (… -> T by <name>: <Actor>).
capability	Declare a capability (a dependency interface) in a context.
commons	Declare a pure, stateless module of types and functions.
consumes	Declare a dependency on another context’s services.
context	Declare a deployable context (services, agents, capabilities).
cron	The cron protocol on a service header (from cron).
do	Perform a unit effect as a statement (do e — the binder-free let _ <- e).
else	The alternative branch of an if expression.
ensures	Declare a function postcondition — a pure Bool clause over the parameters and result (ensures <name>: <pred>).
enum	Declare a payloadless sum type (enum { A, B }).
expect	Assert a predicate inside a test case (expect <bool-predicate>).
exports	Declare which types a context exposes, and how.
false	The boolean literal false.
fn	Declare a function.
from	Name the protocol a service conforms to (service X from http).
given	Declare the capabilities a handler requires.
http	The HTTP protocol on a service header (from http).
if	A conditional expression.
implies	Logical implication (P implies Q ≡ `!P
invariant	Declare an agent invariant — a predicate that must hold of every committed state.
is	Test a value against a variant pattern, yielding a Bool.
let	Bind a local value (let x = …, or let x <- … for an effect).
match	Pattern-match over a sum type, Result, or Option.
opaque	Declare an opaque type, or export a type opaquely.
property	Declare a generative test inside a suite (property "…" { for all … }).
protocol	Reserved keyword (protocols are a closed, compiler-known set).
provides	Provide an implementation of a capability.
queue	The queue protocol on a service header (from queue("name")).
record	Reserved keyword (records are written type X = { … }).
requires	Declare a function precondition — a pure Bool clause over the parameters (requires <name>: <pred>).
self	The current agent instance, inside a handler.
service	Declare a service (a group of handlers) in a context.
stub	Stub a consumed capability operation at a test seam (stub Cap.op(…) returns <v> / fails).
transition	Declare an agent step invariant over the old/new state pair (transition <name>: …).
transparent	Export a type with its structure visible (exports transparent { … }).
true	The boolean literal true.
type	Declare a type: alias, record, sum, opaque, or refined.
uses	Bring a commons into scope.
where	Attach refinement predicates to a base type.

Contextual keywords

Reserved only in the one position named below; elsewhere (a field, parameter, or other identifier) they are ordinary names.

Keyword	Meaning
case	Declare a test case inside a suite (case "…" { … }).
event	Declare a typed fact a context may emit (event Name = { fields }), inside a context.
messages	Declare a message bundle for one locale (messages "<tag>" { "code" => "template" }), inside a commons.
on	Begin a handler declaration (on call, on GET(…), on message, on open/on close).
suite	Declare a test suite targeting a unit (suite <target> { case … }).

Built-in type names

Compiler-known type constructors. They are not lexer keywords — you may use them as an identifier in value position — but they are reserved in type position: a type declaration may not reuse one of these names (bynk.resolve.reserved_builtin_type).

Name	Meaning
Connection	A held WebSocket connection, Connection[F].
History	A generated call-history generator, History[Agent] (test-only).
HttpResult	The HTTP handler result type, HttpResult[T].
List	The immutable list type, List[T].
Map	The immutable map type, Map[K, V].
Query	The lazy storage-read type, Query[T].
QueueResult	The queue handler result type (non-generic).
Stream	The value-over-time primitive, Stream[T].