Is it the same version as Claude 3.5 Sonnet?
No. claude-3-sonnet-20240229 corresponds to the date-fixed Sonnet version of the Claude 3 family; it does not mean it automatically updates to Claude 3.5 or later versions. When existing applications switch models, you should retest prompts, image understanding results, and output formats rather than just replacing the name.
Does a 200K context mean 200K output?
No. The context window describes the model's capacity to process conversations and materials, not the length of a single response. You also need to reserve space for the response; for long reports, it is better to generate an outline first and then expand it by section, rather than treating the entire context size as an output target.
How do I submit an image for analysis?
Combine a text question and a clear image in the text-and-image content blocks supported by the selected interface, and specify the area of interest and expected output. Chat Completions uses text and image_url, while Messages uses its native image content blocks; do not use PDF or video URLs as image_url.
Can it output JSON for programs to read?
You can request JSON text through prompting, and Claude 3 has improved in this kind of structured expression. It is recommended to provide field names, types, and rules for missing values, and to parse and validate on the application side; the ability to generate JSON does not mean it will meet strict Schema constraints every time.
Do I need to resend all history for each follow-up question?
Include user and assistant messages relevant to the current task in messages for Messages or Chat Completions, with the specific format handled according to the selected public interface. Keep the latest code, interim conclusions, and important constraints; when necessary, summarize longer history again to avoid relying on outdated information.