feat(ai): experimental callbacks for streamText#12708
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aayush-kapoor merged 17 commits intomainfrom Feb 20, 2026
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| export type StreamTextOnStartCallback< | ||
| TOOLS extends ToolSet = ToolSet, | ||
| OUTPUT extends Output = Output, | ||
| > = (event: { |
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can the events be extracted (from generate and stream text into XXXEvent types/interfaces) or are there differences?
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extracted - changed for generateText as well
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## Background as a follow up to #12654, we will introduce the same callbacks for the `ToolLoopAgent` ## Summary - added callback `experimental_onStart` that exposes the data/events that happen at the very beginning - added callback `experimental_onStepStart` - added callback `experimental_onToolCallStart` - added callback `experimental_onToolCallFinish` ## Manual Verification ## Future Work - callbacks aren't currently passed through for streaming - will need to merge #12708 first ## Checklist - [x] Tests have been added / updated (for bug fixes / features) - [x] Documentation has been added / updated (for bug fixes / features) - [x] A _patch_ changeset for relevant packages has been added (for bug fixes / features - run `pnpm changeset` in the project root) - [x] I have reviewed this pull request (self-review)
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Background
as a follow up to #12654, we will introduce the same callbacks for streamText function
Summary
experimental_onStartthat exposes the data/events that happen at the very beginningexperimental_onStepStartexperimental_onToolCallStartexperimental_onToolCallFinishManual Verification
Checklist
pnpm changesetin the project root)Future Work