[Bug] spawn 子代理未继承 agent-default-model：主会话走自定义 provider， spawn 子代理被路由到 deepseek-official

[cancerstick]

[Bug] spawn 子代理未继承 agent-default-model：主会话走自定义 provider，
spawn 子代理被路由到 deepseek-official

环境

• dsh 0.1.1-rc.2（npm 全局安装），Windows，web profile
• settings.yaml 配置了自定义 openai-responses provider，并设置：
  agent-default-model: { provider: openrt, model: stealth/ox-alpha }

预期行为

@deepseek-ai/dsh-subagent-spawn-in-process/README.zh.md：
「子 agent ……默认继承父 agent 模型（除非覆盖）」
→ spawn 子代理应使用 openrt/stealth-ox-alpha。

实际行为

• 主会话 session.jsonl.zstd 中 model 字段 838 次全部为
  stealth/ox-alpha（与配置一致）；
• 同期由 subagent 工具 spawn 出的每个子代理会话中，model 字段
  全部为 deepseek-v4-flash-vision-exp（deepseek-official 路由），
  抽查多个子代理结果一致。
• 结果：spawn 子链的 LLM 调用计费走了第一方 DeepSeek 通道，
  用户配置的自定义 provider 对子代理不生效。

复现步骤

1. settings.yaml 配置自定义 provider + agent-default-model 指向它
2. 主对话用 subagent 工具派生子代理执行任意任务
3. 解压 ~/.dsh/sessions///session.jsonl.zstd，
   统计 "model" 字段

影响

• 计费流向与用户配置不一致（意外消耗 DeepSeek 官方额度）
• 自定义 provider 仅对主会话生效，spawn/fork 子链失效

疑问

• 这是 web 组合包对 spawn 模型的有意覆盖，还是继承逻辑的缺陷？
• 若为有意设计，是否有配置键可将 spawn 子代理指回
  agent-default-model？

[nokkies]

Diagnosed the mechanism in the rc.2 source: not intentional, and not the inheritance logic itself -- it is a tier split between what the parent runs and what children inherit.

Agent.options (provider/model) is frozen at session creation, seeded from the default model selection AS OF THAT MOMENT. Everything that steers the model afterwards -- the web model picker, an agent-default-model written to settings mid-flight -- acts through a per-agent selection ref and the agent/request waterfall, then lands in the session log. The parent's own turns therefore follow the CURRENT route (your 838 consistent stealth/ox-alpha entries), but resolveChildAgentOptions in @deepseek-ai/dsh-subagent/src/child-agent.ts inherits parent.options.model -- the create-time snapshot. Your main session was created while the effective default was still deepseek-official's model, so every spawn child inherited that stale seed and billed the first-party channel, exactly as your session logs show. The same stale read sits in the continuable descriptor snapshot (continuation.ts), so the durable child records agree with the wrong route.

Answers to your two questions:

1. Not an intentional web-composition override. No code overrides a child's model toward deepseek-official; the child faithfully inherits a snapshot that no longer describes the parent.
2. No config key rescues it on rc.2. The reliable workaround today is to set agent-default-model BEFORE creating the session (children then inherit the correct seed), or restart the session after changing it.

The fix we applied in our private fork (commit 233e8c6b9b), for reference: inherit the parent's live route -- its latest logged request's config, falling back to the create-time options, taken as a unit so a mixed logged/seed pair cannot name a route that never existed:

export function parentLiveRoute(parent: Agent): { provider?: string; model?: string } {
  const logged = parent.session.requestHeader()?.config
  const provider = logged?.provider ?? parent.options.provider
  const model = logged?.model ?? parent.options.model
  return { ...provider !== undefined ? { provider } : {}, ...model !== undefined ? { model } : {} }
}

used by both resolveChildAgentOptions and the continuable descriptor snapshot. The logged header is the durable record of what the parent actually runs, and it is exactly what the web tier's own selection derives from on a cold read, so the two tiers converge instead of drifting. An explicit per-child agentOptions still overrides both. Happy to share the full patch with tests.

[weijiafu14]

你这份取证很清楚：主会话 838 次全是 stealth/ox-alpha，spawn 出去的子代理全是 deepseek-official 路由。同根因的还有 #4311（options 创建时快照定格）、#4371、#4478（余额被扣光）。这条链在 DSH 自家的 dsh-subagent 里，我们改不了。

要"子代理跟着父会话当前实际在用的路由走"这个结果，可以换一条子代理运行时：

dsh plugin --profile <你的 profile> add pi2dsh
dsh plugin --profile <你的 profile> add @tintinweb/pi-subagents
# 装完重启 dsh

派出的子代理是真正的 DSH 会话，模型三级解析：显式指定 → 否则读调用方当前实时路由（从其会话日志最后一条 request/header 取，会话中途 /model 切过也跟得上，这条在 stock TUI 上实跑核证过）→ 最后才回落创建时快照。同时支持 per-child model 和 per-child 推理档位。

边界：不修复 DSH 原生 subagent / subagent_fork 工具，是并行的另一套。

examples/subagents · 验收报告

[KillYourMatherPackage]

找到根因了 买了第三方的API，子代理走官方，玩了一晚上，突然报欠费了