fix(anthropic): send placeholder for empty assistant turns instead of dropping - #421
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fix(anthropic): send placeholder for empty assistant turns instead of dropping#421cpsievert wants to merge 2 commits into
cpsievert wants to merge 2 commits into
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… dropping Dropping an empty assistant turn could produce two consecutive user messages, violating the API's user/assistant alternation requirement. Send an '[empty string]' placeholder instead, matching ellmer's fix (tidyverse/ellmer#1099) and chatlas's existing empty-text normalization. Closes #416
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Closes #416.
AnthropicProvider._as_message_paramsdropped assistant turns with zero content blocks, which could produce two consecutiveusermessages and violate Anthropic's user/assistant alternation requirement. Now sends an[empty string]placeholder instead, matching ellmer's fix (tidyverse/ellmer#1099, tidyverse/ellmer#1100) and chatlas's existing empty-text normalization in_content.py.Also audited other providers for a similar drop-empty-turn pattern — none exists; the fix is Anthropic-only. The outdated test asserting the dropping behavior was replaced with one asserting the placeholder.