feat(start): share Codex sessions across isolated providers

README.md

@@ -168,6 +168,7 @@ cc-switch provider export <id>       # Export a Claude provider to a standalone
 cc-switch provider stream-check <id> # Check provider stream health
 cc-switch start claude <id>          # Launch Claude with this provider without switching globally
 cc-switch start codex <id>           # Launch Codex with this provider without switching globally
+cc-switch start codex <id> --shared-sessions # Share persistent Codex history across providers
 cc-switch start claude <id> --dry-run # Preview the launch without starting Claude
 cc-switch auth list                  # List managed ChatGPT/Codex OAuth accounts
 cc-switch sessions list --all        # Review saved assistant sessions
@@ -190,6 +191,10 @@ cc-switch --app pi provider list        # Manage Pi providers
 
 Use `cc-switch start` when you want different providers in multiple terminals. It only affects the Claude or Codex session launched by that command; `provider switch` and `use` still change the global provider. In the TUI, select a provider on the Providers page and press `o` for the same behavior.
 
+On macOS/Linux, add `--shared-sessions` to `start codex` to share the configured Codex home's sessions, archived sessions, and SQLite history index. Each provider uses a persistent, private directory under that home's `.cc-switch-launches/`; these directories must remain in place because Codex records session paths through them. Different providers can run concurrently; a second shared launch of the same provider is rejected while the first is running. Codex's per-thread writer locks are shared too, so close an active session before resuming it from another provider. Login changes are saved back to that provider, while launch-specific configuration is kept out of the saved provider settings. Native `--model`, `resume`, and `fork` arguments are supported; `--config`, `--profile`, and `--oss` overrides are not supported in shared mode.
+
+Shared launches use the existing unified `custom` provider identifier without changing the global history setting. To include older official sessions, use the existing **Unified Codex session history** setting and its optional migration. Cross-provider continuation still depends on the upstream accepting the old conversation's content, including encrypted reasoning. The default temporary launch and the TUI `o` shortcut remain unchanged.
+
 See the "Features" section for full command list.
 
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README_ZH.md

@@ -167,6 +167,7 @@ cc-switch provider export <id>       # 导出 Claude 供应商为独立 settings
 cc-switch provider stream-check <id> # 检查供应商流式健康
 cc-switch start claude <id>          # 用指定供应商启动 Claude，不切换全局供应商
 cc-switch start codex <id>           # 用指定供应商启动 Codex，不切换全局供应商
+cc-switch start codex <id> --shared-sessions # 不同供应商共享持久化 Codex 历史
 cc-switch start claude <id> --dry-run # 仅预览启动配置
 cc-switch auth list                  # 查看托管的 ChatGPT/Codex OAuth 账号
 cc-switch sessions list --all        # 查看历史会话
@@ -189,6 +190,10 @@ cc-switch --app pi provider list        # 管理 Pi 供应商
 
 需要在多个终端同时使用不同供应商时，请使用 `cc-switch start`。它只影响由该命令启动的 Claude 或 Codex 会话；`provider switch` 和 `use` 仍会切换全局供应商。在 TUI 的供应商页选中供应商后按 `o`，效果相同。
 
+在 macOS/Linux 上，为 `start codex` 添加 `--shared-sessions`，即可共享当前配置的 Codex 目录中的会话、归档会话和 SQLite 历史索引。各供应商使用该目录下 `.cc-switch-launches/` 中独立、持久化的私有目录；Codex 会通过这些目录记录会话路径，因此请保留它们。不同供应商可以并行运行；同一供应商已有共享实例运行时，会拒绝第二次共享启动。原生 Codex 的会话写锁也会共享，因此切换供应商继续同一会话前，请先退出原会话。登录变更会回写到对应供应商，启动专用配置不会写回供应商设置。支持透传 `--model`、`resume` 和 `fork`；共享模式不支持 `--config`、`--profile` 和 `--oss` 覆盖。
+
+共享启动复用已有的统一 `custom` 供应商标识，不改变全局历史设置。若需纳入旧的官方会话，请使用现有的「统一 Codex 会话历史」设置及其可选迁移。跨供应商继续对话仍取决于上游能否接受原会话内容，包括加密推理内容。默认临时启动和 TUI 的 `o` 快捷键保持原有行为。
+
 完整命令列表请参考「功能特性」章节。
 
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