hasura/graphql-engine · error · TypePredicateError

Invalid operator used in type '{type_name:}' predicate: '{op

Error message

Invalid operator used in type '{type_name:}' predicate: '{operator_name:}'

What it means

A type predicate used an operator name that is not valid for that type's boolean expression. Each boolean expression type exposes a fixed operator vocabulary; referencing any other operator string fails resolution with the type and offending operator name.

Source

Thrown at v3/crates/metadata-resolve/src/types/error.rs:466

    #[error(
        "field '{field_name}' of type '{type_name}' used in a field comparison is an array type and therefore cannot be compared to a single value"
    )]
    UnsupportedFieldComparisonToArrayType {
        field_name: Spanned<FieldName>,
        field_type: QualifiedTypeReference,
        type_name: Qualified<CustomTypeName>,
    },
    #[error(
        "field '{field_name}' of type '{type_name}' used in a field comparison is a predicate type and therefore cannot be compared to a single value"
    )]
    UnsupportedFieldComparisonToPredicateType {
        field_name: Spanned<FieldName>,
        field_type: QualifiedTypeReference,
        type_name: Qualified<CustomTypeName>,
    },

    #[error("Invalid operator used in type '{type_name:}' predicate: '{operator_name:}'")]
    InvalidOperatorInTypePredicate {
        type_name: Qualified<CustomTypeName>,
        operator_name: Spanned<OperatorName>,
    },
    #[error("Nested predicate used in type '{type_name:}'")]
    NestedPredicateInTypePredicate {
        type_name: Qualified<CustomTypeName>,
    },
    #[error(
        "no boolean expression found for type '{type_name:}' This is required when filtering a nested field. Please ensure the model you are filtering has a filterExpressionType defined."
    )]
    NoBooleanExpressionFields {
        field_name: Spanned<FieldName>,
        type_name: Qualified<CustomTypeName>,
    },
    #[error(
        "relationship '{relationship_name}' is used in predicate but does not exist for type '{type_name}'"
    )]

View on GitHub (pinned to 724551b9ae)

Solutions

Check `operator_name` for typos (e.g. `_eque` -> `_eq`)
Look up the operators the type's boolean expression actually supports and use one of those
Enable/map the operator in the connector's metadata or boolean expression definition if it should be supported
Test filters per-connector rather than assuming a universal operator set

Example fix

// before
{"field": "name", "operator": "_equals", "value": "bob"}
// after
{"field": "name", "operator": "_eq", "value": "bob"}

Defensive patterns

Strategy: validation

Validate before calling

// Validate operators against the type's declared predicate operators
if !type_predicate.operators.contains_key(&operator_name) {
    return Err(format!("operator {operator_name} not valid for type"));
}

Type guard

fn operator_valid(tp: &TypePredicate, op: &OperatorName) -> bool {
    tp.operators.contains_key(op)
}

Try / catch

if let Err(TypePredicateError::InvalidOperatorInTypePredicate { type_name, operator_name }) = result {
    return Err(format!("{operator_name} unsupported on {type_name}; check available operators"));
}

Prevention

Derive operator choice from the connector/expression schema, not hardcoding
Add filter unit tests per connector type

When it happens

Trigger: Using an operator like `_regex`, `_ilike`, or a custom name not defined in the type's predicate operators; typos in operator names; assuming Postgres-style operators exist on non-Postgres connectors.

Common situations: Switching connectors (e.g. Postgres to DynamoDB) while keeping the same filters; connector not supporting a given operator on a type; custom boolean expressions with a restricted operator set.

Related errors

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/67b3dbd89f75896c. Report an issue: GitHub.