feat: 提升 Codex custom tool 事件兼容

[huangye123]

背景

本次变更参考 Wei-Shaw/sub2api#3065 中 Codex 模拟保真度的低风险部分，聚焦两个已确认范围：

1. 在不改既有可工作请求头的前提下，补齐 Responses 请求中 include 的合并逻辑。
2. 补齐上游 custom_tool_call / response.custom_tool_call_input.delta 事件在 Chat Completions 与 Anthropic 兼容路径中的处理。

现有实现已经具备较完整的 Codex UA / Originator / Session / WebSocket 头部策略，因此本 PR 不调整请求头相关逻辑，避免破坏已有可工作指纹组合。

修改前

include 行为

PrepareResponsesBody 在请求没有 include 时会默认注入：

["reasoning.encrypted_content"]

但如果客户端已经传入了其他 include，即使请求包含 reasoning，也不会补充 reasoning.encrypted_content。例如：

{
  "reasoning": {"effort": "high"},
  "include": ["file_search_call.results"]
}

旧行为会原样保留 include，导致 reasoning 加密内容项缺失。

custom tool call 事件

旧逻辑主要识别：

• function_call
• response.function_call_arguments.delta

对于新版上游可能返回的：

• custom_tool_call
• response.custom_tool_call_input.delta

部分路径无法按工具调用处理，可能出现工具参数增量无法映射、非流式工具调用提取缺失，或旧无状态转换 fallback 将 custom tool input delta 当普通文本输出的问题。

修改后

include 合并

新增 Codex include 合并辅助逻辑：

• 无 include 时保持原默认行为，注入 reasoning.encrypted_content。
• 有 reasoning 且已有 include 时，如缺少 reasoning.encrypted_content 则追加。
• 保留既有 include 项。
• 已存在时不重复追加。
• 非数组 include 保守不覆盖，避免破坏客户端自定义异常输入。

custom tool call 兼容

补齐以下兼容逻辑：

• Chat Completions 有状态流转换支持 custom_tool_call。
• 支持 response.custom_tool_call_input.delta / done。
• 同时映射 item.id 与 call_id 到同一 OpenAI tool call index，兼容上游 delta 使用不同 ID 字段回传。
• 非流式 completed output 提取支持 custom_tool_call，并从 input 字段读取参数。
• Anthropic 流式转换支持 custom_tool_call 与 response.custom_tool_call_input.delta。
• Anthropic 非流式 completed fallback 支持 custom_tool_call。
• Chat / Anthropic handler 的 delta 字符统计纳入 custom tool input delta。
• 旧无状态 TranslateStreamChunk 显式忽略 response.custom_tool_call_input.delta/done，避免被 fallback 当作普通文本输出；同时保留旧 function_call_arguments.delta 行为，减少回归风险。

前后对比分析

兼容性

• 不修改 Codex HTTP / WebSocket 请求头生成逻辑。
• 不修改 User-Agent、Originator、OpenAI-Beta、Session_id、Conversation_id、Authorization 等既有请求头策略。
• include 逻辑为加法合并，保留既有项且不重复。
• custom_tool_call 被映射到 OpenAI/Anthropic 现有工具调用结构，对旧 function_call 行为保持兼容。

风险控制

• 对异常非数组 include 不强行覆盖，避免破坏未知客户端输入。
• custom tool delta 同时支持 item_id 与 call_id，降低上游事件字段差异导致的索引丢失风险。
• 对无状态转换路径只显式忽略 custom tool input delta，不改变旧 function call delta fallback 行为。
• 新增定向测试覆盖 include 合并、去重、custom tool delta、非流式 tool call 提取与 Anthropic 流式转换。

行为变化

• 当请求包含 reasoning 且已有 include 数组但缺少 reasoning.encrypted_content 时，会自动追加该项。
• 上游返回 custom_tool_call / response.custom_tool_call_input.delta 时，将按工具调用参数增量处理，而不是丢失或误当普通文本。

测试情况

已执行以下测试：

go test ./proxy -run "TestStreamTranslator_CustomToolCallInputDelta|TestStreamTranslator_FunctionCall|TestPrepareResponsesBody_(MergesReasoningInclude|DoesNotDuplicateReasoningInclude)" -count=1

结果：

ok   github.com/codex2api/proxy

go test ./proxy ./proxy/wsrelay -count=1

结果：

ok   github.com/codex2api/proxy
ok   github.com/codex2api/proxy/wsrelay

go test ./admin ./api ./auth ./cache ./config ./database ./internal/imageproc ./internal/imagestore ./internal/signedasset ./proxy ./proxy/wsrelay ./security ./security/promptfilter -count=1

结果：

ok   github.com/codex2api/admin
ok   github.com/codex2api/api
ok   github.com/codex2api/auth
ok   github.com/codex2api/cache
ok   github.com/codex2api/config
ok   github.com/codex2api/database
ok   github.com/codex2api/internal/imageproc
ok   github.com/codex2api/internal/imagestore
ok   github.com/codex2api/internal/signedasset
ok   github.com/codex2api/proxy
ok   github.com/codex2api/proxy/wsrelay
ok   github.com/codex2api/security
ok   github.com/codex2api/security/promptfilter

另外执行：

git diff --check

结果：无空白错误。Windows 环境下仅出现 Git 换行提示 LF will be replaced by CRLF the next time Git touches it。

未通过 / 未执行说明

执行 go test ./... 时，根包因当前 worktree 缺少前端构建产物失败：

main.go:29:12: pattern frontend/dist/*: no matching files found

该失败与本 PR 的 Go 代码修改无关；已用除根包外的全部 Go 子包测试进行覆盖验证。

修改总结

本 PR 在不改既有可工作请求头的前提下，补齐了 Codex Responses 请求体 include 合并和 custom tool call SSE 事件兼容能力，提升 Codex 模拟保真度与新版上游事件格式兼容性，并通过定向测试与相关 Go 子包测试验证。

Summary by CodeRabbit

• New Features

  • Extended tool call support to include custom tool calls alongside function calls. Tool inputs are now properly handled and translated in both streaming and non-streaming response modes.

• Tests

  • Added test coverage for custom tool call input deltas, streaming behavior, and token estimation.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: cbb4c831-ddad-4554-93dc-8ffd6be7cf46

📥 Commits

Reviewing files that changed from the base of the PR and between fabab0d and 588a192.

📒 Files selected for processing (6)

• proxy/anthropic.go
• proxy/anthropic_test.go
• proxy/handler.go
• proxy/handler_anthropic.go
• proxy/translator.go
• proxy/translator_test.go

---

📝 Walkthrough

Walkthrough

Extends Codex-to-OpenAI and Codex-to-Anthropic translators to recognize custom_tool_call items and response.custom_tool_call_input.delta/done events, mapping them into standard tool call output with call_id-to-id fallback and input-field argument sourcing. Also refactors reasoning.encrypted_content include injection from unconditional to conditional helper functions.

Changes

custom_tool_call Translation Support

Layer / File(s)	Summary
Helper predicates and StreamTranslator/ExtractToolCalls core proxy/translator.go	Introduces isCodexToolCallItem and isCodexToolInputDeltaEvent predicates. Updates TranslateStreamChunk to skip custom_tool_call_input events, extends TranslateParsed to announce and stream custom_tool_call items with call_id/id fallback, and updates ExtractToolCallsFromOutput to extract custom_tool_call items using the input field.
Anthropic streaming and non-streaming translator proxy/anthropic.go	Routes response.custom_tool_call_input.delta into the existing tool-input buffer, extends handleOutputItemAdded to create tool_use blocks for custom_tool_call, and extends buildAnthropicResponseFromCompleted to build tool_use blocks with input-field sourcing.
Token estimation char counting in handler paths proxy/handler.go, proxy/handler_anthropic.go	Replaces hardcoded response.function_call_arguments.delta string comparisons with isCodexToolInputDeltaEvent in deltaCharCount accumulation across stream and non-stream paths in both handlers.
Tests for custom_tool_call translation proxy/anthropic_test.go, proxy/translator_test.go	Adds TestAnthropicStreamTranslator_CustomToolCallInputDelta, TestStreamTranslator_CustomToolCallInputDelta, and extends the ExtractToolCallsFromOutput fixture to include a custom_tool_call item (expected count: 2 → 3).

Reasoning Include Handling Refactor

Layer / File(s)	Summary
Include helpers, wiring, and tests proxy/translator.go, proxy/translator_test.go	Adds codexReasoningEncryptedContentInclude constant and ensureDefaultCodexInclude/ensureCodexReasoningInclude helpers; replaces unconditional include initialization; adds tests for include merging and deduplication.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• james-6-23/codex2api#235: Modifies the same prepareResponsesBodyWithOptions path in proxy/translator.go around reasoning.encrypted_content sanitization and inclusion logic, intersecting directly with the include refactor in this PR.

Poem

🐇 A custom tool call came knocking one day,
The translator said, "I know the way!"
With call_id fallback and input in hand,
I map every chunk across OpenAI land.
No delta goes lost, no include unseen —
The fluffiest proxy there's ever been! 🌟

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 29.17% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title is in Chinese and translates to 'feat: Enhance Codex custom tool event compatibility'. It accurately reflects the main changes: adding support for custom_tool_call events and improving include parameter merge logic.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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