hasura/graphql-engine · error · CommandsError::NDCValidationError

NDC validation error: {0}

Error message

NDC validation error: {0}

What it means

Commands-stage error variant that wraps an NDCValidationError during command resolution. NDC validation checks the data connector's capabilities/schema document against the NDC spec; failures are surfaced with the 'NDC validation error:' prefix.

Source

Thrown at v3/crates/metadata-resolve/src/stages/commands/error.rs:152

        "An error occurred while mapping arguments in the command {command_name:} to the procedure {procedure_name:} in the data connector {data_connector_name:}: {error:}"
    )]
    CommandProcedureArgumentMappingError {
        data_connector_name: Qualified<DataConnectorName>,
        command_name: Qualified<CommandName>,
        procedure_name: ProcedureName,
        error: ArgumentMappingError,
    },
    #[error("{error:} in command {command_name:}")]
    CommandTypeMappingCollectionError {
        command_name: Qualified<CommandName>,
        error: TypeMappingCollectionError,
    },

    #[error("{0}")]
    DataConnectorError(#[from] data_connectors::NamedDataConnectorError),
    #[error("{0}")]
    GraphqlConfigError(#[from] graphql_config::GraphqlConfigError),
    #[error("NDC validation error: {0}")]
    NDCValidationError(#[from] NDCValidationError),
}

View on GitHub (pinned to 724551b9ae)

Solutions

1. Inspect the inner NDCValidationError details
2. Update the data connector to a version matching the expected NDC spec
3. Fix the capabilities/schema document the connector serves

Catch and inspect the inner NDCValidationError to report which capability/schema checks failed.

When it happens

Trigger: A command backed by a data connector whose capabilities response or schema fails NDC spec validation while metadata-resolve builds command metadata.

Common situations: Data connector returns non-conformant capabilities JSON after an upgrade, or an old connector version emits a schema the spec validator rejects.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• unable to parse server endpoint: %w
• function {function_name} is not defined in data connector {d
• {0}
• ndc validation error: {0}
• Plugin {plugin_name} references unknown data connector {data

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/bcfc29390bea7e5f. Report an issue: GitHub.