fix(anthropic): allow null content in compaction_delta streaming schema#12471
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aayush-kapoor merged 3 commits intovercel:mainfrom Feb 20, 2026
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Co-Authored-By: Embedder <215220128+embedder-dev@users.noreply.github.com>
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…ma (#12471) ## Background PR #12384 introduced support for Anthropic's compaction feature, but the streaming Zod schema for compaction_delta events requires content to be a non-nullable string. Anthropic's API sends compaction_delta events with content: null (e.g. the initial frame before the compaction summary text), which causes Zod validation to fail at runtime. ## Summary Changed content: z.string() to content: z.string().nullish() in the compaction_delta streaming schema in packages/anthropic/src/anthropic-messages-api.ts. This matches the existing content_block_start schema for compaction, which already uses .nullish(). ## Manual Verification Reproduction requires streaming a conversation that exceeds the compaction trigger threshold (50k+ tokens) with @ai-sdk/anthropic, which triggers a compaction_delta event with content: null. This is not practical to verify without an API key and a large conversation, but the added regression test simulates this exact scenario by streaming a compaction_delta chunk with content: null. ## Checklist - Tests have been added / updated (for bug fixes / features) - Documentation has been added / updated (for bug fixes / features) - A patch changeset for relevant packages has been added (for bug fixes / features - run pnpm changeset in the project root) - I have reviewed this pull request (self-review) ## Related Issues Fixes #12470 --------- Co-authored-by: Embedder <215220128+embedder-dev@users.noreply.github.com> Co-authored-by: Aayush Kapoor <83492835+aayush-kapoor@users.noreply.github.com>
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✅ Backport PR created: #12718 |
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…aming schema (#12718) This is an automated backport of #12471 to the release-v5.0 branch. FYI @leog25 Co-authored-by: leo <78882874+leog25@users.noreply.github.com> Co-authored-by: Embedder <215220128+embedder-dev@users.noreply.github.com> Co-authored-by: Aayush Kapoor <83492835+aayush-kapoor@users.noreply.github.com>
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Background
PR #12384 introduced support for Anthropic's compaction feature, but the streaming Zod schema for compaction_delta events requires content to be a non-nullable string. Anthropic's API sends compaction_delta events with content: null (e.g. the initial frame before the compaction summary text), which causes Zod validation to fail at runtime.
Summary
Changed content: z.string() to content: z.string().nullish() in the compaction_delta streaming schema in packages/anthropic/src/anthropic-messages-api.ts. This matches the existing content_block_start schema for compaction, which already uses .nullish().
Manual Verification
Reproduction requires streaming a conversation that exceeds the compaction trigger threshold (50k+ tokens) with @ai-sdk/anthropic, which triggers a compaction_delta event with content: null. This is not practical to verify without an API key and a large conversation, but the added regression test simulates this exact scenario by streaming a compaction_delta chunk with content: null.
Checklist
Related Issues
Fixes #12470