@param-later-invoked-callable

The @param-later-invoked-callable tag marks a callable argument that is kept by the function or method and invoked only after the call has already returned — an event listener being registered, a callback stashed for a future tick of an event loop, and similar patterns. This matters to static analysis for the opposite reason @param-immediately-invoked-callable does: variables captured by reference into the callback cannot be trusted to hold any particular value once the outer call returns, since the callback body has not actually run yet, and the function storing it cannot be assumed pure just because the callback itself might be.

"@param-later-invoked-callable" <Variable>
    [ <Description> ]

Parsing a @param-later-invoked-callable tag produces a VariableTag instance exposing $variable: the parameter's name, without the leading $. The type of the callable itself is whatever the parameter's own @param already declares.

final class ParamLaterInvokedCallableTag extends VariableTag
{
    // Adds nothing of its own; $variable is
    // declared on the parent VariableTag.
    public readonly string $variable;
}

The opposite case — a callable guaranteed to run before the call returns — is documented with @param-immediately-invoked-callable instead.

PHPStan documents @param-later-invoked-callable alongside its other callable-related tags; Psalm has no equivalent.

05 July 2026