修复: OpenAI格式请求转Claude时系统提示词拼接失败

[PoseidonLi0514]

问题: 当用户通过OpenAI格式(v1/chat/completions)发送请求，后端渠道为Claude时， ConvertOpenAIRequest返回dto.ClaudeRequest类型，但compatible_handler.go中 仅对dto.GeneralOpenAIRequest做类型断言，导致断言失败，系统提示词拼接逻辑被跳过。

修复: 将单一类型断言改为type switch，新增*dto.ClaudeRequest分支，
复用claude_handler.go中已验证的系统提示词拼接逻辑。

Summary by CodeRabbit

• Improvements
  • Enhanced system prompt handling for Claude-compatible requests with new override capabilities.
  • Improved system prompt consistency and application across different AI request types, ensuring proper prompt augmentation in all scenarios.
  • Refined system message handling to support both string-based and structured message formats.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 49370398-9c72-4d4d-b239-4614b8d4528f

📥 Commits

Reviewing files that changed from the base of the PR and between 34893b0 and 6f67d1f.

📒 Files selected for processing (1)

• relay/compatible_handler.go

---

Walkthrough

A type switch in compatible_handler.go replaces direct type assertion to differentiate handling of GeneralOpenAIRequest and ClaudeRequest, enabling system prompt detection and override logic tailored to each request format, including string and media message conversion for Claude.

Changes

Cohort / File(s)	Summary
System Prompt Override Handler relay/compatible_handler.go	Type switch replaces assertion to handle GeneralOpenAIRequest and ClaudeRequest separately. OpenAI requests detect missing system prompts and prepend or override within Messages. Claude requests initialize System field when nil and support override logic with string/media message format conversion.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• fix: 使用openai兼容接口调用部分渠道在最终端点为claude原生端点下还是走了openai扣减input_token的逻辑 #2883: Modifies Claude vs OpenAI request detection and handling logic in the same file.
• fix: claude & gemini endpoint system prompt overwrite #1850: Adds SystemPrompt override logic for Claude requests in claude_handler.go with similar functionality.
• 修改claude system参数为数组，增加通用性 #1692: Changes Claude Request System field representation to array of ClaudeMediaMessage, affecting the same system message handling paths.

Suggested reviewers

• seefs001
• Calcium-Ion

Poem

🐰 A rabbit hops through prompts with glee,
OpenAI and Claude, now unified thee,
System messages dance in type-switched delight,
Override the old, make the new shine bright! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title is in Chinese and describes fixing system prompt concatenation for OpenAI-format requests converted to Claude format, which directly matches the PR objectives and changes made.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

📝 Coding Plan

• Generate coding plan for human review comments

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

Tip

CodeRabbit can generate a title for your PR based on the changes.

Add @coderabbitai placeholder anywhere in the title of your PR and CodeRabbit will replace it with a title based on the changes in the PR. You can change the placeholder by changing the reviews.auto_title_placeholder setting.