hasura/graphql-engine · error · RequestError::ValidationFailed

validation failed: {0}

Error message

validation failed: {0}

What it means

RequestError::ValidationFailed is returned when the parsed GraphQL document fails semantic validation against the schema. It wraps gql::validation::Error, so the message is 'validation failed: {0}' with the specific rule violation (unknown field, wrong argument type, etc.). Like other RequestErrors it is raised before execution of root fields begins.

Source

Thrown at v3/crates/graphql/frontend/src/error.rs:14

use axum::response::IntoResponse;
use engine_types::ExposeInternalErrors;
use gql::http::GraphQLError;
use lang_graphql as gql;
use tracing_util::{ErrorVisibility, TraceableError};

/// Request errors are raised before execution of root fields begins.
/// Ref: <https://spec.graphql.org/October2021/#sec-Errors.Request-errors>
#[derive(Debug, thiserror::Error)]
pub enum RequestError {
    #[error("parsing failed: {0}")]
    ParseFailure(#[from] gql::ast::spanning::Positioned<gql::parser::Error>),

    #[error("validation failed: {0}")]
    ValidationFailed(#[from] gql::validation::Error),

    #[error("{0}")]
    IRConversionError(#[from] graphql_ir::Error),

    #[error("{0}")]
    GraphQlPlanError(#[from] graphql_ir::GraphqlIrPlanError),

    #[error("explain error: {0}")]
    ExplainError(String),
}

impl RequestError {
    pub fn to_graphql_error(&self, expose_internal_errors: ExposeInternalErrors) -> GraphQLError {
        let message = match (self, expose_internal_errors) {
            // Error messages for internal errors from IR conversion and Plan generations are masked.
            (
                Self::IRConversionError(graphql_ir::Error::Internal(_)),

View on GitHub (pinned to 724551b9ae)

Solutions

1. Compare the query against the current schema via GraphiQL autocomplete or an introspection query and fix the flagged field/argument
2. Regenerate client code (graphql-codegen, Apollo CLI) against the updated schema
3. Check the wrapped validation error message and location for the exact rule that failed
4. If a field was removed/renamed server-side, update the query or restore the field in metadata

Example fix

// before
query { usr(id: 1) { nm } }

// after
query { user(id: 1) { name } }

// Client-side pre-validation against the schema:
import { buildSchema, validate, parse } from 'graphql';
const schema = buildSchema(await fetchIntrospection());
const errors = validate(schema, parse(query));
if (errors.length) throw new Error(errors.map(e => e.message).join('; '));

match frontend.execute(&req).await {
    Err(e @ RequestError::ValidationFailed(v)) => {
        // v has message + locations; return GraphQL-style errors with 400
        respond_validation_error(v)
    }
    rest => rest,
}

When it happens

Trigger: A syntactically valid GraphQL document that references undefined fields/arguments, passes arguments of the wrong type, uses unknown directives, subscribes to non-subscription fields, or violates any validation rule in the October 2021 spec section on validation.

Common situations: Schema drift: client was built against an older schema where a field existed; typos in field names; missing variables or wrong variable types; introspection-based codegen out of date after a schema change.

Related errors

• parsing failed: {0}
• Unexpected value: expecting {expected_kind:}, but found: {fo
• '{name:}' is not a valid GraphQL name.
• '{alias:} is not a valid alias
• {value} is not a valid limit value

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/19d5ece08f616946. Report an issue: GitHub.