juspay/hyperswitch · error

Failed to serialize default

Error message

Failed to serialize default

What it means

Error "Failed to serialize default" thrown in juspay/hyperswitch.

Source

Thrown at crates/router/src/core/configs/dimension_config.rs:58

macro_rules! config {
    // Object config variant (with object = true)
    (
        superposition_key = $key:ident,
        output = $output:ty,
        default = $default:expr,
        object = true,
        requires = $requirement:ty,
        targeting_key = $targeting_type:ty
    ) => {
        paste::paste! {
            pub struct [<$key:camel>];

            impl superposition::Config for [<$key:camel>] {
                type Output = serde_json::Value;
                type TargetingKey = $targeting_type;
                const SUPERPOSITION_KEY: &'static str = superposition_consts::$key;
                fn default_value() -> Self::Output {
                    serde_json::to_value(&$default).expect("Failed to serialize default")
                }
            }

            impl $requirement {
                pub async fn [<get_ $key:lower>](
                    &self,
                    storage: &dyn StorageInterface,
                    superposition_client: &superposition::SuperpositionClient,
                    targeting_key: Option<&$targeting_type>,
                ) -> $output {
                    // Fetch JSON and convert to $output using the conversion function
                    crate::core::configs::fetch_db_config_for_objects::<[<$key:camel>], $output>(
                        storage, superposition_client, self, targeting_key
                    ).await
                }
            }
        }
    };

View on GitHub (pinned to 3093f22cc4)

Solutions

1. Ensure the default dimension config value is serializable (valid JSON) in configuration

When it happens

Trigger: Thrown at crates/router/src/core/configs/dimension_config.rs:58 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of juspay/hyperswitch@3093f22cc4 (2026-08-19). Data as JSON: /api/errors/99961cc0e0f01fc9. Report an issue: GitHub.