fix(codex-proxy): merge multiple system messages into one leading message - #2688
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EKKOLearnAI merged 2 commits intoAug 23, 2026
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…sage Codex 0.149 sends both a top-level `instructions` string and `developer` messages inside `input`. The responses->chat_completions adapter converted each into its own system message, leaving the second one mid-conversation. Providers such as vLLM reject this with: 400 BadRequestError: "System message must be at the beginning." consolidateChatSystemMessages() now keeps exactly one leading system message, merging any additional system messages into it in original order. Fixes web-ui coding-agent (codex + custom:qwen) run failures with vLLM-backed OpenAI-compatible providers. Refs: repro via mock capture of codex 0.149 responses payload
…system position The adapter now relocates in-input developer messages to the front as a single leading system message, so the expected message order changes from [user, system] to [system, user].
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问题 / Problem
Codex 0.149 发起请求时会同时携带两处 system 级指令：
instructions字段（核心系统提示，实测 ~20KB）input数组中的role: "developer"消息（web-ui 写入的developer_instructions）responsesToOpenAiChat适配器把两者各转成一条system消息，第二条落在对话中间。vLLM 等严格校验的消息顺序，直接拒绝：影响：web-ui 编程工具（Codex / Claude Code）在 scoped 模式 + OpenAI-compatible vLLM provider（如 Qwen via vLLM）下 每次 请求都会失败。
修复 / Fix
新增
consolidateChatSystemMessages()：转换完成后将所有system消息按原始顺序合并为一条置顶消息；仅一条 system 时保持原样（含图片 content 不被 stringify），只在其位于对话中间时移到开头。验证 / Verification
roles: [system, user, user]→ 直接请求 vLLM/v1/chat/completions→ HTTP 200，模型正常回复openAiChatToResponses）含 tool_calls 场景验证通过