> ## 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 04 27 ## Project-scoped ECM fitting Equivalent-circuit-model fitting is now available directly inside a project. Pick any measurement already attached to one of the project's cells (or upload a fresh CSV), preview the trace, run the fit, and save the result back to the project as a new model with one click. The new flow adds a model-vs-data plot, an error plot, a fitting-progress indicator, an OCV toggle helper, and auto-scrolls to the results when the fit completes. The standalone ECM demo continues to work for unauthenticated users. ## PyBaMM v26.4.0 support The simulation engine has been updated for PyBaMM v26.4.0, which introduces a dedicated `Rest` step class in place of the old zero-current step and renames the MSMR electrode-capacity parameters from short keys (e.g. `Q_n_1`, `Q_p_1`) to descriptive strings (e.g. "Negative electrode host site occupancy capacity (1) \[A.h]"). Existing experiments and MSMR parameter sets continue to parse correctly under the new release. ## SDK skills as a Claude Code plugin The Ionworks Python SDK now ships with a set of installable Claude Code skills covering api-discovery, cell-data, data-upload, simulations, pipelines, and projects-and-studies. Each skill documents the relevant sub-clients, method signatures, and the create-or-get patterns so an AI assistant can drive the SDK against the current API surface. Install via `/plugin marketplace add ionworks/ionworks-skills` and `/plugin install ionworks` to get the slash commands and SessionStart hook for any Ionworks project. ## Strict upload validators in the Python API `CellMeasurementClient.create` and `create_or_get` now run optional client-side validators before sending data to Studio so processing bugs surface as a local error instead of a confusing upload result. A hard time-gap check (>5 h between consecutive rows) runs by default; passing `voltage_window` enables a voltage-continuity check (catches chronological misordering from a faulty data split), and passing `rated_capacity` enables a consecutive same-direction full-step check plus a soft warning for any step whose capacity exceeds 5× rated. **Improvements** * Measurement chart controls collapse into a compact header summary; per-axis variable selectors now allow adding and removing series dynamically with a unified two-column layout. **Fixes** * Study visualization no longer collapses to an empty state when switching between studies whose experiment-type tabs differ — the filter resets to All when the previous tab isn't present. * Users with a stale session can recover by signing out via the sign-in page instead of being stuck on the redirect. * The empty cells page now uses the correct organization-level permission check, so users who can create cells no longer see a misleading "contact a project admin" message. * Pipeline element details view no longer triggers rapid duplicate fetches for `Data Fit` and `Validation` configs. **Improvements** * Simulations now compile faster by default, speeding up repeated runs that share the same model. * Simulation objectives with custom mesh or spatial-method settings (such as `CycleAgeing`) now serialise and reload correctly. **Fixes** * Time-monotonicity validation error message now reports the correct two adjacent values (the previous off-by-one showed the values just before the actual violation). **Fixes** * Sign-convention detection no longer misclassifies low-current pulse datasets as all-rest; the rest threshold now scales relative to the 95th-percentile current so violations are caught on small-amplitude data.