docs: add the observability integration guide (en+zh)

README.md

@@ -66,6 +66,7 @@ flowchart LR
 | Negotiation content API | Supports `information` / `feasibility` / `target` negotiation types plus `abort` termination messages, with template-driven negotiation message generation and validation; negotiation session state travels in the message metadata (`negotiationContext`) and the SDK itself is stateless |
 | Resource organization | Bundled prompt resources (`prompts` / `scenarios` / `slots` / `templates` / `negotiation-vocabulary`) ship with the package, supporting both `packaged` built-in resources and `local_file` local files |
 | LLM adaptation | Connects to external LLMs through OpenAI-compatible call chains, retrying retryable error codes up to the configured attempt limit |
+| Observability | Automatically records traces, duration metrics, and structured logs of A2A-T interactions based on OpenTelemetry; integrate with one registration on the client and one wrapper on the server, with no business code changes, and it can be switched off entirely as needed |
 | Bundled samples | The repository ships runnable sample scenarios such as `subscribe_incident` (event subscription); without an API key they automatically degrade to scripted mock LLM responses, running end to end with zero external dependencies |
 
 ## Project Structure
@@ -82,6 +83,7 @@ The repository is organized with `uv`; the core code lives under `src/a2a_t`:
 | `llm` | LLM adaptation layer with a default OpenAI-compatible client; supports custom LLM integration |
 | `prompt` | Prompt resource analysis, slot extraction, template rendering, and validation |
 | `negotiation` | Negotiation content models, the generation pipeline, and the validation pipeline |
+| `observability` | The observability module, automatically recording interaction traces, metrics, and logs (requires the `a2a-t-sdk[observability]` extra dependency) |
 | `a2a-t-sample` | Runnable client/server sample case collection |
 | `a2a-t-corpus` | Accuracy verification corpus (pure test assets): data-driven workflow cases |
 
@@ -159,7 +161,7 @@ More runnable samples (event subscription end-to-end, RAN energy saving with neg
 
 | Document | Location | Content |
 | --- | --- | --- |
-| Developer Guide | [docs/en/developer_guide.md](docs/en/developer_guide.md) | Feature introduction, installation and integration, parameter configuration, and minimal practices |
+| Developer Guide | [docs/en/developer_guide.md](docs/en/developer_guide.md) | Feature introduction, installation and integration, parameter configuration, observability integration, and minimal practices |
 | API Reference | [docs/en/API_Reference.md](docs/en/API_Reference.md) | Full API definitions and usage of `A2ATClient` / `A2ATServer` |
 
 ## Current Support Scope

README_zh.md

@@ -66,6 +66,7 @@ flowchart LR
 | 协商内容 API | 支持 `information` / `feasibility` / `target` 三类协商及 `abort` 终止消息，提供模板驱动的协商报文生成与校验；协商会话状态随消息 metadata（`negotiationContext`）往返，SDK 本身无状态 |
 | 资源组织 | 内置提示词资源（`prompts` / `scenarios` / `slots` / `templates` / `negotiation-vocabulary`）随包提供，支持 `packaged` 内置资源与 `local_file` 本地文件两种加载方式 |
 | LLM 适配 | 通过 OpenAI 兼容调用链接入外部大模型；对可重试错误码按配置的尝试次数上限重试 |
+| 可观测性 | 基于 OpenTelemetry 自动记录 A2A-T 交互的调用链、耗时指标与结构化日志；客户端注册一次、服务端包装一次即可接入，无需修改业务代码，支持按需整体关闭 |
 | 内置示例 | 随仓库提供 `subscribe_incident`（事件订阅）等可运行示例场景，未配置 API Key 时自动降级为脚本化 Mock LLM，零外部依赖即可端到端跑通 |
 
 ## 项目结构
@@ -82,6 +83,7 @@ flowchart LR
 | `llm` | LLM 适配层，默认提供 OpenAI 兼容客户端，支持自定义 LLM 接入 |
 | `prompt` | 提示词资源分析、槽位提取、模板渲染与校验 |
 | `negotiation` | 协商内容模型、生成管线与校验管线 |
+| `observability` | 可观测性模块，自动记录交互调用链、指标与日志（需安装 `a2a-t-sdk[observability]` 额外依赖） |
 | `a2a-t-sample` | 可运行的客户端/服务端示例用例集 |
 | `a2a-t-corpus` | 准确性验证语料（纯测试资产）：数据驱动工作流用例 |
 
@@ -157,7 +159,7 @@ uv run mypy src      # 类型检查
 
 | 文档 | 位置 | 内容 |
 | --- | --- | --- |
-| 开发指南 | [docs/zh/开发指南.md](docs/zh/开发指南.md) | 特性介绍、安装接入、参数配置与最小实践 |
+| 开发指南 | [docs/zh/开发指南.md](docs/zh/开发指南.md) | 特性介绍、安装接入、参数配置、可观测性集成与最小实践 |
 | API 参考 | [docs/zh/API参考.md](docs/zh/API参考.md) | `A2ATClient` / `A2ATServer` 全量 API 定义与使用说明 |
 
 ## 当前支持范围