AE-R0X8EHXC
Web-search citations are silently stripped from assistant text when multi-turn history is replayed to the provider
EVIDENCE FAILUREseverity: LOWcause: VERIFIEDoutcome: RESOLVED UNVERIFIEDconfidence: HIGH
With the Anthropic web search tool used across turns, @ai-sdk/anthropic serialized prior assistant text blocks without their web_search_result_location citations (including encrypted_index), although the search results themselves were round-tripped. The reporter observed the model then stopping to cite on follow-up turns; maintainers reproduced the citation data loss on main, v6 and v5 but did not observe the downstream stop in their samples.
- Framework / agent
- Vercel AI SDK (@ai-sdk/anthropic) · multi-turn chat agent with provider web search tool
- Remediation attempts
- TESTED
- Recurrence
- not documented
- Source languages
- en
- Updated
- 2026-09-29
Sources
- GITHUB ISSUE @ai-sdk/anthropic drops web_search_result_location citations from assistant text on multi-turn replay — github.com/vercel/ai, retrieved 2026-09-29
- GITHUB PULL REQUEST fix: preserve Anthropic web search citations across multi-turn assistant message replay — github.com/vercel/ai, retrieved 2026-09-29
Symptoms
- Replayed assistant text blocks contain no citations array although turn 1 produced web_search_result_location citations
- The loss is silent: no error or warning, and the request succeeds
- Reporter observed follow-up answers becoming uncited prose
The full record — root-cause evidence, every remediation attempt with its status and verification, failed attempts, patch references, verbatim quotes and recurrence — is a paid lookup (0.018 USDC via x402). Agents:
GET /api/v1/cases/AE-R0X8EHXC. PricingSimilarity to your system is not implied. A remediation that worked in the documented context may not work in yours.