Diagnostic code map

Diagnostic codes follow Appendix B of the specification: EK, the two-digit VIP number, then two digits for the rule. A code change does not change which programs a diagnostic rejects. Update saved diagnostic filters and expected-output assertions to the new code.

Previous code	Appendix B code	Rule and repair
`EK4617`	`EK0103`	`await` does not run an Effect in an `async` function. Use `await runPromise(program)`.

The language server keeps the numeric code (103) with source EK; the terminal and diagnostic references write EK0103.

Remaining renumberings

Previous code	Current code	Rule
`EK0201`	a `do` expression that ends in a declaration, a loop or an `if` without an `else`
`EK0202`	a `break` or `continue` whose target is outside its `effect` block
`EK4615`	`EK0502`	The same diagnostic rule with Appendix B numbering
`EK4605`	`EK1903`	The same diagnostic rule with Appendix B numbering
`EK4606`	`EK1904`	The same diagnostic rule with Appendix B numbering
`EK2001`	`EK9201`	Legacy rule awaiting retirement by its owning VIP
`EK2002`	`EK9202`	Legacy rule awaiting retirement by its owning VIP
`EK2003`	`EK9203`	Legacy rule awaiting retirement by its owning VIP
`EK2004`	`EK9204`	Legacy rule awaiting retirement by its owning VIP
`EK2101`	`EK9205`	Legacy rule awaiting retirement by its owning VIP
`EK2102`	`EK9206`	Legacy rule awaiting retirement by its owning VIP
`EK2103`	`EK9207`	Legacy rule awaiting retirement by its owning VIP
`EK3006`	`EK9208`	Legacy rule awaiting retirement by its owning VIP
`EK2126` (parameter count)	`EK2801`	More than four generic `data` parameters
`EK2126` (constraint)	`EK2126`	A constrained generic `data` parameter

The temporary EK92xx codes preserve older checks whose numbers Appendix B reassigns to different rules. They are not new language rules. Interim EK92xx codes cannot be configured in vibe.severities: an entry is EK3006. An infallible catch expression stays valid when its interim EK9204 report retires; the separate imported lint is EK3818. Their owning VIP implementations retire them. Other older codes keep their existing numbers until their VIP implementation removes or replaces the check.

Appendix B reference

Registration reserves a code; it does not mean the compiler already implements every rule. The chapters describe the intended language; the VIP implementation lanes own remaining behavior gaps.

Code	Rule
`EK0101`	`effect f() { }` or `async f() { }` outside a class or object literal
`EK0102`	`await`, `for await` or `await using` in effect code
`EK0103`	`await` on an Effect in an `async` function
`EK0104`	`effect` on a getter, setter or constructor
`EK0105`	`effect` and `async` on one function
`EK0106`	an `effect` function whose written return type is not an Effect
`EK0107`	`eval`, `Function`, `arguments`, `var` or `with` in a `.vibe` file
`EK0108`	a recognized `effect` modifier on an `abstract` declaration, in an ambient `declare` context, or on an `interface` or type literal member
`EK0109`	a typed or generic bare `effect` arrow head; parenthesize its parameters
`EK0301`	`!` beside a union, an intersection, a function type or a conditional type without parentheses
`EK0401`	a `throw` or a call that may throw in a plain function whose return type is effectful, or a parameter default that may throw in any effectful function, or a local implementation whose tracked throws exceed an exposed effectful overload's implicit `never` bound
`EK0402`	a function that may throw where a function type doesn't admit its thrown type
`EK0403`	an unwrapped call, `new` expression or tagged template that may throw, in effect code or a plain `catch` handler
`EK0404`	an unwrapped Promise-producing call, `new` expression, tagged template or `async match` in effect code
`EK0405`	a body that throws more than its written `@throws {T}`
`EK0501`	`try` outside effect code, the top level included
`EK0502`	`try` on a value that is not an Effect
`EK0503`	a `try` statement in effect code
`EK0504`	`catch` outside effect code
`EK0505`	`try x catch h`
`EK0506`	`e catch h` where `e` is not an Effect
`EK0507`	a handler whose result is a Promise or thenable
`EK0508`	lint warning: a plain handler whose result is an Effect; use `catch effect`
`EK0801`	warning: `using` in effect code; use `acquireDisposable` inside `scoped`
`EK0901`	a `static key` without `readonly`, or whose initializer is not a string literal
`EK0902`	a service member that is not a `PropertySignature`, `MethodSignature`, `KeyMember` or `DefaultMember`
`EK0903`	a service with no derived key and no `static readonly key`
`EK1201`	`provide` outside effect code
`EK1301`	a constructor in an `error` or `schema error` body
`EK1302`	a user-written `static` member or setter in an `error` or `schema error` body
`EK1303`	type parameters on an `error` or `schema error` declaration
`EK1304`	any other `RejectedElement` in an `error` or `schema error` body; an `implements` clause
`EK1401`	a namespace name that two subpaths export, or a subpath and the root
`EK1501`	`export default schema S …`; write `export { S as default }`
`EK1502`	type parameters on a `schema` declaration; use an ordinary generic TypeScript factory
`EK1603`	`export default data D { … }`; write `export { D as default }`
`EK1701`	`fork` or `join` outside effect code
`EK1703`	a `fork` operand that is not an Effect
`EK1801`	a `try.all` operand that is not an array of Effects
`EK1901`	a `for concurrent` operand that is not an `Iterable`
`EK1902`	`for concurrent` outside effect code
`EK1903`	`break` leaving a `for concurrent` body
`EK1904`	`return` in a `for concurrent` body
`EK1905`	a labeled `continue` naming a statement that encloses the `for concurrent`
`EK2001`	`for try` outside effect code
`EK2002`	`return` in a `for try` head binding initialization or body
`EK2003`	a labeled `break` or `continue` from a `for try` head binding initialization or body to a statement outside it
`EK2004`	a `for try` operand that is not a `Stream`
`EK2102`	a producer whose written return type is not a `Stream`
`EK2103`	`yield*` in a producer
`EK2109`	a `schema` field type outside the mapping, including a shadowing type without a suitable Schema value
`EK2111`	`restore` outside an `uninterruptible` block
`EK2117`	an `extends` clause or a `_tag` member in an `error` or `schema error` body, or a computed `schema error` key whose runtime domain cannot be proved to exclude `"_tag"`
`EK2126`	a constraint on a generic `data` type parameter
`EK2201`	an interruption block outside effect code
`EK2202`	`restore` in a `for concurrent` head binding initialization or body, or `restore` that captures an outer mask across an `effect` function, arrow, method, producer or block
`EK2301`	an unparenthesized conditional at either end of a pipe, `x \|> f(%) ? a : b`; write `(x \|> f(%)) ? a : b` or `x \|> (f(%) ? a : b)`; `vibelang --fix` writes the second, the old reading
`EK2801`	a `data` declaration with more than 4 type parameters
`EK2803`	a default on a generic `data` type parameter
`EK3001`	two services with the same key
`EK3002`	a class extends a service
`EK3003`	`new` on a service
`EK3004`	`instanceof` a service
`EK3005`	a generic service
`EK3006`	an error code or an unknown code in `vibe.severities`; remove the entry
`EK4402`	a value import of a Node builtin, with or without `node:` (`node:fs`, `fs`), or a reference to a banned platform global, in a `.vibe` file
`EK4609`	lint warning: `await` on a `Fiber` in an `async` function; use `join`
`EK4610`	lint warning: `await` on a `Deferred` in an `async` function; use `try Deferred.await(d)`
`EK4701`	a `match` with no `default` over a finite union that misses a case; a guarded arm covers nothing

EK0510 reports an unparenthesized try, fork or join on the left of **. The editor action wraps the whole execution expression, such as (try program) ** 2, in parentheses. vibelang --fix applies the same repair when it introduces no new error. Native TypeScript unary expressions retain TS17006.