feat: upgrade LLM adapters to support Gemini 3, Claude 4.5, and GPT-5…

[hashangit]

[0.4.1] - 2025-12-18

🤖 Next-Gen LLM Adapter Upgrades

• Gemini 3 Family Support:
  • Full support for Gemini 3 Pro, Flash, and Deep Think models.
  • Implemented native systemInstruction support for improved behavioral steering.
  • Added thinkingLevel control (low, minimal, medium, high) to balance reasoning depth and latency.
  • Updated default model to gemini-3-flash.
• Claude 4.5 Family Support:
  • Support for Claude 4.5 Opus, Sonnet, and Haiku.
  • Maintained and optimized support for thinking tokens and reasoning blocks.
  • Updated default model to claude-4.5-sonnet.
• GPT-5 Family Support:
  • Full support for GPT-5, GPT-5.1, and GPT-5.2 (including Instant, Thinking, and Pro variants).
  • Updated default model to gpt-5.2-instant.
• SDK Dependencies: Upgraded @google/genai, @anthropic-ai/sdk, and openai to their latest December 2025 versions.

🛠 Refactors & Maintenance

• Improved integration test resilience by ensuring tests skip correctly when API keys are missing.
• Updated documentation and README to reflect v0.4.1 status.

[gemini-code-assist]

Summary of Changes

Hello @hashangit, 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 significantly expands the framework's capabilities by integrating the latest generations of leading Large Language Models (LLMs) from Google, Anthropic, and OpenAI. These upgrades enable developers to leverage advanced features like native system instructions and granular control over reasoning processes, ensuring the framework remains at the forefront of agentic AI development. The update also includes essential SDK dependency bumps and minor maintenance to improve overall stability and developer experience.

Highlights

• Gemini 3 Family Support: Added comprehensive support for Gemini 3 Pro, Flash, and Deep Think models, including native systemInstruction and thinkingLevel control for granular reasoning depth.
• Claude 4.5 Family Support: Integrated support for Claude 4.5 Opus, Sonnet, and Haiku models, maintaining optimized thinking token and reasoning block capabilities.
• GPT-5 Family Support: Implemented full support for the GPT-5, GPT-5.1, and GPT-5.2 variants, including Instant, Thinking, and Pro models.
• SDK Dependency Upgrades: Updated @google/genai, @anthropic-ai/sdk, and openai to their latest December 2025 versions to ensure compatibility and access to new features.
• Improved Test Resilience: Enhanced integration tests to correctly skip when API keys are missing, preventing failures in environments without full credentials and improving CI/CD stability.

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[gemini-code-assist]

Code Review

This pull request effectively upgrades the LLM adapters to support new models from Google, Anthropic, and OpenAI, including Gemini 3, Claude 4.5, and the GPT-5 family. The changes align well with the description, notably the refactoring of the Gemini adapter to leverage native systemInstruction support, which is a significant improvement. The dependency upgrades and enhancements to integration test resilience are also valuable additions. I've included a couple of minor suggestions to fix a typo in the changelog and improve comment consistency in the Anthropic adapter. Overall, this is a well-executed update.

[gemini-code-assist]

There appears to be a stray 2. on this line which seems to be a typo. It should be removed to maintain the clean formatting of the changelog.

[gemini-code-assist]

The example model IDs in this comment use underscores (e.g., claude_4.5_sonnet), which is inconsistent with the default model ID defined on line 15 (claude-4.5-sonnet) and Anthropic's typical model naming convention, which uses hyphens. Using hyphens in the examples would improve consistency and reduce potential confusion for developers.

Suggested change

	/** The default Anthropic model ID to use (e.g., 'claude_4.5_sonnet', 'claude_4.5_opus'). */
	/** The default Anthropic model ID to use (e.g., 'claude-4.5-sonnet', 'claude-4.5-opus'). */