ellmer 0.4.2

• AssistantTurn gains a finish_reason property that reports why the model stopped generating (@thisisnic, #3).
• batch_chat() now supports chat_google_gemini() and chat_groq() for batch processing (@xmarquez, #914, #927).
• Chat gains a set_model() method for updating the model after chat creation. Unlike some chat_*() functions, the model name is not validated (#988).
• chat() now raises a warning and chat_structured() raises an informative error when a response is truncated, filtered, or otherwise incomplete (@thisisnic, #867).
• Default models have been updated for a number of providers (@thisisnic, #885, #1038):
  • chat_anthropic() now uses claude-sonnet-4-6.
  • chat_aws_bedrock() now uses us.anthropic.claude-sonnet-4-6.
  • chat_databricks() now uses databricks-claude-sonnet-4-6.
  • chat_deepseek() now uses deepseek-v4-flash.
  • chat_github() now uses gpt-5.4.
  • chat_google_gemini() now uses gemini-3.5-flash.
  • chat_groq() now uses openai/gpt-oss-20b.
  • chat_openai() now uses gpt-5.
  • chat_openrouter() now uses gpt-5.4.
  • chat_snowflake() now uses claude-sonnet-4-6.
• chat_anthropic() now supports params(reasoning_effort =) for Claude's adaptive thinking mode (@thisisnic, #987).
• chat_deepseek() no longer errors during tool calling when the assistant turn has no text content (@thisisnic, #1043).
• chat_google_gemini() and chat_google_vertex() now support params(reasoning_effort =) (@thisisnic, #873).
• chat_google_vertex() and models_google_vertex() now default location and project_id to the GOOGLE_CLOUD_LOCATION and GOOGLE_CLOUD_PROJECT environment variables, no longer incorrectly use GOOGLE_API_KEY for authentication, and give a clearer error when cached credentials are invalid (@thisisnic, #994).
• chat_ollama() now supports params(reasoning_effort = ...) to set thinking for reasoning models, and thinking content is now captured in turns (@thisisnic, #940).
• chat_perplexity() now defaults to model = "sonar" since the previous default ("llama-3.1-sonar-small-128k-online") has been removed by Perplexity (@thisisnic, #538).
• chat_portkey() no longer errors when when using a custom Portkey gateway without the PORTKEY_VIRTUAL_KEY env var being set (@thisisnic, #872).
• New chat_posit() and models_posit() provide access to models hosted by Posit AI, authenticating via an OAuth device flow (@simonpcouch, #1024).
• models_deepseek() lists available models for chat_deepseek() (@jcrodriguez1989, #919).
• models_groq() lists available models for chat_groq() (@thisisnic, #921).
• type_object(.additional_properties) is deprecated. No supported provider can return additional properties when using structured output. Instead, use an array of name-value pairs (@thisisnic, #866).