GraphQL RFC Tracker

RFC 1 / Proposal

CoerceInputValue()

Opened on2025-07-04
Updated on2025-07-08

At a glance

Spec PR description

As an alternative to #1058 and #1178 - this is a more substantial overhaul of how input value coercion is defined in favor of a system of composed algorithms.

A quick summary of what this introduces:

  • Introduces the concept of a coercion failure which has a similar "raised error" behavior, but is caught and translated into specific errors based on each callsite. That removes the awkwardness of "a request error is actually an execution error here".

  • A new "Input Coercion" section which defines CoerceInputValue(). This is the point of reusability which handles nullability and then forks out to each specific input type.

  • Algorithms for each kind of type's input coercion. Notably input objects and lists which have been under-defined (as an alt to #1058).

  • A validation rule for default variable values, which I believe exists in graphql.js but was missing in spec.

Open Qs:

  • Is this the right place for the Input Coercion subsection?

  • Have I missed anything?

Timeline