# SymbolResolveExtension [Integration guide](https://docs.lumencharts.com/charting-library/reference/compatibility) · [Reference index](https://docs.lumencharts.com/charting-library/api/) Public contract reference. This declaration describes types and callback shapes; availability is constrained by the linked integration guide and the runtime capability. Legacy product-specific fields are not a promise of implementation. ## currencyCode {#currencycode} ```ts currencyCode?: string; ``` Use the type signature above and the integration guide for the owning capability. ## unitId {#unitid} ```ts unitId?: string; ``` Use the type signature above and the integration guide for the owning capability. ## session {#session} ```ts session?: string; ``` Use the type signature above and the integration guide for the owning capability. --- Documentation page: https://docs.lumencharts.com/charting-library/api/SymbolResolveExtension