hasura/graphql-engine · error · Error

introspection query failed: {0}

Error message

introspection query failed: {0}

What it means

Wrapper around errors from the introspection execution module itself: the introspection query ran but the introspection resolver returned an error (detailed message in {0}). It aggregates any failure while building the schema response for introspection.

Source

Thrown at v3/crates/graphql/lang-graphql/src/generate_graphql_schema.rs:21

for each namespace from the schema.
 */
use json_ext;
use std::collections::BTreeMap;
use std::sync::OnceLock;
use tracing_util::SpanVisibility;
use tracing_util::{ErrorVisibility, TraceableError};

#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("unable to parse introspection query: {0}")]
    ParseIntrospectionQuery(String),
    #[error("unable to normalize introspection query: {0}")]
    NormalizeIntrospectionQuery(String),
    #[error("unable to find field call")]
    FieldCallNotFound,
    #[error("Only __schema field is expected but found: {name:}")]
    OnlySchemaFieldExpected { name: String },
    #[error("introspection query failed: {0}")]
    IntrospactionQueryError(#[from] crate::introspection::Error),
    #[error("unable to serialize to json: {0}")]
    SerializeJson(#[from] serde_json::Error),
}
impl TraceableError for Error {
    fn visibility(&self) -> ErrorVisibility {
        ErrorVisibility::User
    }
}

/// Generate GraphQL schema for a given namespace
pub fn build_namespace_schema<
    S: crate::schema::SchemaContext,
    NSGet: crate::schema::NamespacedGetter<S>,
>(
    namespaced_getter: &NSGet,
    schema: &crate::schema::Schema<S>,
) -> Result<serde_json::Value, Error> {

View on GitHub (pinned to 724551b9ae)

Solutions

1. Read the inner error message to identify the concrete introspection failure
2. Ensure metadata is fully applied and the schema is valid before introspecting
3. Upgrade the engine if the inner error indicates an internal bug
4. Reproduce with a minimal schema and report upstream

// Ensure schema is fully built before exposing introspection
if (!engine.isReady()) return 503;

// Catch, unwrap the inner introspection error ({0}) and surface its concrete message

When it happens

Trigger: Executing introspection when the introspection resolver fails — e.g. encountering an invalid type or field name while walking the schema, or internal invariants breaking while serializing the schema.

Common situations: Schemas containing exotic or invalid names; partially built schemas during startup; introspecting before metadata is fully applied.

Related errors

• unable to fetch introspection schema: %w
• error in fetching introspection schema: %w
• %s: %d %s
• %s: decoding graphql response errors: %w
• %s: %w

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/a92438308d9aeb6b. Report an issue: GitHub.