> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ionworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 2026 02 16

<Update label="February 16, 2026" description="Permissions, optimizer selection, and Arbin protocol support">
  ## Role-based permissions for projects

  Studio now supports granular role-based permissions at the project level. Contributors and viewers see only the actions they are allowed to perform, with UI elements hidden or disabled based on their role. Admins can manage project membership directly from organization settings.

  ## Optimizer selection in optimization creation

  When creating an optimization, you can now choose from multiple optimizer algorithms — XNES, CMAES, SNES, PSO, Differential Evolution, and Nelder-Mead — and configure hyper-parameters like step size and population size directly in the UI.

  [Find out more →](/optimize/overview#optimizer-selection)

  ## Arbin protocol support

  The protocol simulator now supports Arbin cycler protocols, including variable callback rules for fine-grained control over protocol simulations.

  [Find out more →](/simulate/simulating-commercial-protocols)

  ## In-project protocol simulation

  Protocol simulations can now be run directly within a project context, using a parameterized model from that project instead of a generic one. A new Protocol Simulator page is available in the project navigation.

  [Find out more →](/simulate/simulating-commercial-protocols)

  <AccordionGroup>
    <Accordion title="Studio">
      **Improvements**

      * Optimization jobs now scale background evaluation capacity with population size for more reliable large-population runs.
      * Extended job timeout to 14 days with automatic failure cascading to child jobs.
      * The "View" button in the simulation list is now in its own column for quicker access.

      **Fixes**

      * Fixed plot loading requiring two loads — plots now initialize correctly on first view.
      * Added search functionality to simulation plot dropdowns.
      * Fixed composite plating simulation bugs with SOC calculation error handling and missing variable detection.
      * Fixed voltage components plot reliability with proper loading states and data availability checks.
      * Fixed pipeline element list showing elements from other pipelines.
      * Fixed pending job status menu not displaying for optimization and data fit jobs.
      * Fixed linked parameters in pipeline baseline construction.
      * Fixed organization member list appearing empty on the admin settings page.
      * Fixed users being redirected to project list with an error after creating a new project.
      * Fixed permission guard to wait for project data before checking permissions.
    </Accordion>

    <Accordion title="Pipeline">
      **Improvements**

      * Added a Gaussian negative log-likelihood cost function for optimization. Deprecated `MLE` in favor of `SSE`.
      * Improved reliability of loading and re-running saved solver configurations.
      * Parameter cleanup now correctly handles nested expressions and dependent parameters.
      * Flat prior format is now supported alongside the nested format for simpler configuration.
      * Added missing API documentation for Arrhenius, piecewise conversion, and piecewise interpolation classes.
    </Accordion>

    <Accordion title="Python API">
      **Improvements**

      * Standardized error parsing for the new backend error format while remaining backward-compatible. Pipeline failures are now surfaced via `raise_on_failure`.
    </Accordion>

    <Accordion title="Protocol Simulator">
      **Improvements**

      * Added cycle aging experiment template for long-duration degradation studies.
      * Additional Arbin protocol file formats can now be parsed and simulated.
      * Simulation results are now saved to disk during solve for improved reliability with long-running protocols.

      **Fixes**

      * Fixed amp-hour tracking in step charge protocols.
      * Fixed Arbin protocol parsing regression from a previous change.
    </Accordion>
  </AccordionGroup>
</Update>