Improvements in 3.26.1 AI Assistant

• Reduced AI assistant token consumption with a better progressive-disclosure approach for model metadata discovery, which should help avoid hitting input token rate limits.
• Enabled use of caching for Anthropic models (which weren't cached previously)
• Better, more targetted tools that help LLMs produce better results, including a model metadata search tool.
• The OpenAI and Anthropic AI providers now support an optional base URL override, enabling use with OpenAI regional endpoints and models deployed in Microsoft Foundry.
• For Open AI and Anthropic, the model name field is now pre-populated with known models, while still allowing custom model names.
• Hovering over the AI chat token counter displays a tooltip with a breakdown of full-price input tokens, cached input tokens, cache writes, and output tokens. The slider bar continues to show context window pressure. Table Import Wizard
• The Table Import Wizard now filters the catalog and schema lists for Databricks connections based on the settings already specified on the data source. When a catalog is already configured, the wizard skips the catalog query. Tables and views are filtered by schema when one is specified, reducing clutter in large catalogs.
• New Databricks connections now default to Implementation 2.0 in the connection dialog. Existing connections that do not explicitly specify an Implementation version are left unchanged.
• Added support for Databricks service principal authentication using OAuth Machine-to-Machine (M2M) flow. A new "OAuth (M2M)" option in the Databricks connection dialog lets you authenticate with a Client ID and Client Secret. The ODBC driver handles token acquisition and refresh automatically. This works across all Databricks clouds (Azure, AWS, GCP). Bugfixes in 3.26.1
• Fixed a bug where always-inject custom instructions (e.g. core.md) were included in both the base system prompt and the per-turn injection, causing ~1,200 tokens of duplicated content on every API call.
• Fixed an issue where Ctrl+Z (undo) and Ctrl+Y (redo) keyboard shortcuts were not working in the AI Assistant chat input field.
• Fixed an issue where the AI Assistant would fail with an HTTP 400 error when using models that do not support custom temperature values (e.g. OpenAI o-series reasoning models). The assistant now automatically retries without the temperature parameter when this error is detected.
• Fixed low-contrast rendering of inline code (e.g., Tokenize()) inside user chat messages on the light theme.
• Fixed an issue where clicking "Allow" (not "Allow for session") on a consent prompt would silently grant consent to a second tool call in the same turn without prompting. Each tool call now requires its own consent when using one-time approval.
• Fixed an issue where the AI Assistant's knowledge base search would fail when the query contained special characters such as # (e.g. searching for "C# language support").
• Fixed the AI provider endpoint tooltip not updating when switching between providers in the preferences dialog.
• Fixed an issue where the AI Assistant errored when chatting with models hosted on Databricks via a custom OpenAI-compatible provider.
• Fixed an issue where AI Assistant tool calling silently failed when using custom OpenAI-compatible providers such as OpenRouter. The assistant would receive tool call requests from the model but never execute them, causing it to appear stuck or respond with text only.
• Fixed the "Updating document content" inline marker showing the document ID instead of the new content in its tooltip and Copy button.
• Fixed the OpenAI Project ID preference being incorrectly bound to Organization ID.
• Fixed an issue where the Table Import Wizard would reconstruct Databricks M expression options from scratch instead of preserving the original data source options, potentially losing non-default settings.
• Fixed a bug that would cause the TOM Explorer / Properties view to "lock up" after a failure occurred in the Import Table Wizard, requiring a restart of the application.
• Fixed some localization issues where certain UI strings were not translatable.
• Fixed an unhandled FileNotFoundException on startup when the Microsoft Edge WebView2 runtime is partially installed or corrupted.
• Fixed an issue where modal message dialogs (e.g. "No schema changes detected") could appear on a different monitor than the main application window, making Tabular Editor appear frozen. Dialogs now always appear centered on the main form's monitor, and clicking the disabled main form flashes the dialog to draw attention.
• Fixed a NullReferenceException that could occur when importing tables from a Fabric Lakehouse, if the data source identifier had changed since the table import settings were last saved (e.g. after upgrading the model's compatibility level or switching partition types).
• Fixed an issue where the Windows Account Manager (WAM) authentication dialog could appear behind the "please wait" spinner during operations like "Update table schema", making the application appear frozen while waiting for user interaction on a hidden dialog.