feat(go/plugins/anthropic): support native structured output

[hugoaguirre]

Checklist (if applicable):

• PR title is following https://www.conventionalcommits.org/en/v1.0.0/
• Tested (manually, unit tested, etc.)
• Docs updated (updated docs or a docs bug required)

[gemini-code-assist]

Summary of Changes

Hello @hugoaguirre, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces native support for structured JSON output when interacting with Anthropic models. By leveraging Anthropic's tool use capabilities, it allows developers to specify a JSON schema for the desired output, ensuring that model responses adhere to a predefined structure. This enhancement streamlines the integration of Anthropic models into applications that require reliable and parseable data formats, improving developer experience and reducing post-processing efforts.

Highlights

• Enhanced Model Capabilities: Updated default Claude model options to support Multimodal capabilities, laying groundwork for more advanced interactions.
• Native Structured Output Support: Implemented core logic to detect and process requests for structured JSON output, both for non-streaming and streaming responses from Anthropic models.
• Tool-Based JSON Transformation: Introduced a new handleStructuredOutput helper function that transforms Anthropic's internal tool call responses into raw JSON output, ensuring adherence to specified schemas.
• Dynamic Request Generation: Modified the toAnthropicRequest function to dynamically add a return_json_output tool and enforce its use via ToolChoice when a JSON output schema is provided in the model request.
• Comprehensive Testing: Added a dedicated test case (TestToAnthropicRequest_StructuredOutput) to verify the correct generation of Anthropic requests for structured output, ensuring reliability of the new feature.

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Changelog

• go/plugins/anthropic/models.go
  • Updated default Claude model options to support Multimodal capabilities.
• go/plugins/internal/anthropic/anthropic.go
  • Added isStructured flag to identify structured output requests.
  • Integrated handleStructuredOutput calls for both streaming and non-streaming responses.
  • Extended streaming event handling to process input_json_delta for structured output.
  • Implemented handleStructuredOutput function to convert tool requests to JSON text.
  • Modified toAnthropicRequest to include a return_json_output tool and set ToolChoice when a JSON output schema is present.
• go/plugins/internal/anthropic/anthropic_test.go
  • Added encoding/json import.
  • Introduced TestToAnthropicRequest_StructuredOutput to validate structured output request generation.

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[gemini-code-assist]

Code Review

This pull request adds support for native structured output in the Anthropic Go plugin. The changes look good overall. I've identified a few areas for improvement:

• Error Handling: There's a place where an error from json.Marshal is ignored, which could lead to silent failures.
• Maintainability: There's some duplicated code for checking structured output conditions and a hardcoded string that could be extracted into a constant.
• Testing: The new test for structured output could be more robust in its schema verification.

I've left specific comments with suggestions for these points.

[hugoaguirre]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for native structured output to the Anthropic Go plugin by leveraging the OutputConfig feature in the updated Anthropic SDK. The changes include updating the model capabilities, modifying the request creation to use OutputConfig for constrained JSON output, and making tool schemas stricter. New live tests have been added to verify the structured output functionality in both regular and streaming modes.

My review focuses on improving code maintainability by reducing duplication in tests, enhancing the robustness of the schema enforcement logic, and correcting a unit test that was verifying an outdated implementation pattern. Overall, this is a great feature addition.

[hugoaguirre]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for native structured output in the Anthropic Go plugin. The changes include updating the Anthropic SDK, modifying the model capabilities to declare support for constrained generation, and implementing the logic to use Anthropic's OutputConfig for structured output requests. New live tests have been added to verify this functionality for both streaming and non-streaming cases. The implementation looks solid, but I've identified a couple of areas where in-place modification of schemas could lead to side effects, and a minor redundancy in a test case.