diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9e88590..f76be96 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -29,3 +29,10 @@ message handling.
 
 By submitting a contribution, you agree that it is licensed under Apache
 License 2.0.
+
+## README capability summary
+
+Changes to Node entrypoints, Endpoint operations or Tool APIs must update the root
+English `README.md` and Chinese `README_zh.md` capability summaries in the same
+change; keep the files separate and add reciprocal language links. Follow the [Node README contract](https://github.com/PhyAgentOS/forge/blob/master/CONTRIBUTING.md#node-readme-contract);
+count Nodes, Endpoints, operations and deployment Tools separately.
diff --git a/README.md b/README.md
index c262531..92b8ca1 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # Forge Motion
 
+[English](README.md) | [简体中文](README_zh.md)
+
 Dora-native motion planning and execution orchestration for Forge robots.
 
 ```text
@@ -14,6 +16,37 @@ The repository is a UV workspace of independently installable motion packages. V
 with `forge-motion-server`; shared trajectory processing, collision checking, planning scenes, and
 streaming servo packages should only be extracted when real additional consumers require them.
 
+## Node, Endpoint and Tool API
+
+| Item | Current implementation |
+| --- | --- |
+| Production Nodes | 2: `motion_server` and `motion_action_policy`; source commands `forge-motion-server` and `forge-motion-action-policy` |
+| Auxiliary programs | Examples such as fake plants are excluded from the production Node count |
+| Tool integration | Dora `ToolMessage` provider; caller-facing access through Gateway |
+| Direct HTTP Tool API | 0; the Nodes do not listen on HTTP; Gateway owns the invocation URL |
+| Endpoints | 1: `motion.server`; its provider is `motion_action_policy`, not `motion_server` |
+| Operations | 2: `move_joints` and `move_pose` (both Action, cancellable, status supported; each descriptor has maximum concurrency 1) |
+| Gateway Tools | Deployment-defined in `tools.specs`; `robot-control-sim` binds 2 Tools to these operations |
+
+| Tool ID (robot-control-sim configuration) | Endpoint / operation | Provider Node |
+| --- | --- | --- |
+| `sim.set_joint_positions` | `motion.server / move_joints` | `motion_action_policy` |
+| `sim.move_eef` | `motion.server / move_pose` | `motion_action_policy` |
+
+```text
+Gateway -> motion_action_policy -> motion_server -> joint_trajectory_controller -> Adapter / simulator
+```
+
+`motion_action_policy` handles the Tool lifecycle and Wire argument translation;
+`motion_server` handles fresh state, FK/IK, trajectories and controller orchestration.
+They are separate Nodes: the word `server` in the Endpoint ID does not route the provider to the compute Node.
+For arguments, units and validation, see the [Action endpoint](packages/motion_server/src/forge_motion_server/action_endpoint.py)
+and [motion_server package guide](packages/motion_server/README.md). Joint values use rad/m according to joint type; pose positions use metres.
+
+Compatibility: current dependency declarations are `dora-rs==0.4.1`, `forge-kinematics==1.0.1`, `forge-msgs==1.0.1`. See [pyproject.toml](packages/motion_server/pyproject.toml) and [uv.lock](uv.lock). The Tool protocol implementation is vendored in this repository. These declarations do not guarantee cross-version interoperability; also check the build revision and Skill lock when using artifacts.
+
+Changes to Node entrypoints, Endpoints or Tool APIs must update this section and the associated configuration/contracts. Follow the [Node README contract](https://github.com/PhyAgentOS/forge/blob/master/CONTRIBUTING.md#node-readme-contract).
+
 ## Packages
 
 - `packages/motion_server`: fresh-state validation, Forge FK/IK, joint-space time
diff --git a/README_zh.md b/README_zh.md
new file mode 100644
index 0000000..7ae078d
--- /dev/null
+++ b/README_zh.md
@@ -0,0 +1,76 @@
+# Forge Motion
+
+[English](README.md) | [简体中文](README_zh.md)
+
+面向 Forge 机器人的 Dora 原生运动规划与执行编排。
+
+```text
+操作 / 应用目标
+        -> MoveJoints / MovePose
+        -> MotionServer
+        -> FollowJointTrajectory
+        -> 面向执行器的控制器
+```
+
+仓库是由可独立安装的运动包组成的 uv 工作区。0.1 版本从 `forge-motion-server` 开始；
+轨迹处理、碰撞检查、规划场景和流式伺服仅在确有额外使用方时再抽成共享包。
+
+## Node、Endpoint 与 Tool API
+
+| 项目 | 当前实现 |
+| --- | --- |
+| 生产 Node | 2：`motion_server` 与 `motion_action_policy`；源码命令分别为 `forge-motion-server`、`forge-motion-action-policy` |
+| 辅助程序 | fake plant 等示例不计入生产 Node 数 |
+| Tool 接入方式 | Dora `ToolMessage` provider；通过 Gateway 暴露调用入口 |
+| 直接 HTTP Tool API | 0；本 Node 不监听 HTTP，调用地址属于 Gateway |
+| Endpoint 数 | 1：`motion.server`；provider 是 `motion_action_policy`，不是 `motion_server` |
+| operation 数 | 2：`move_joints`、`move_pose`（均为 Action，可取消、可查状态；各自 descriptor 最大并发 1） |
+| Gateway Tool 数 | 由 `tools.specs` 决定；`robot-control-sim` 为这两个 operation 配置 2 个 Tool |
+
+| Tool ID（robot-control-sim 配置） | Endpoint / operation | provider Node |
+| --- | --- | --- |
+| `sim.set_joint_positions` | `motion.server / move_joints` | `motion_action_policy` |
+| `sim.move_eef` | `motion.server / move_pose` | `motion_action_policy` |
+
+```text
+Gateway -> motion_action_policy -> motion_server -> joint_trajectory_controller -> Adapter / simulator
+```
+
+`motion_action_policy` 管 Tool 生命周期和 Wire 参数转换；`motion_server` 管新鲜状态、FK/IK、轨迹及控制器编排。
+两者是两个 Node，不能因 Endpoint 名含 `server` 而把 provider 路由接到计算 Node。
+参数、单位与校验以 [Action endpoint](packages/motion_server/src/forge_motion_server/action_endpoint.py)
+和 [motion_server 包说明](packages/motion_server/README.md)为准；关节值按关节类型使用 rad/m，位姿位置为 m。
+
+兼容性：当前依赖声明为 `dora-rs==0.4.1`、`forge-kinematics==1.0.1`、`forge-msgs==1.0.1`；以 [pyproject.toml](packages/motion_server/pyproject.toml) 与 [uv.lock](uv.lock) 为准。 Tool 协议实现为仓库内 vendored 代码。 这些声明不构成跨版本互操作保证；使用制品时还需核对 build revision 和 Skill lock。
+
+后续修改 Node 入口、Endpoint 或 Tool API 时，请同步更新本节及对应配置/契约，遵循 [Node README 规范](https://github.com/PhyAgentOS/forge/blob/master/CONTRIBUTING.md#node-readme-contract)。
+
+## 包组成
+
+- `packages/motion_server`：新鲜状态校验、Forge FK/IK、关节空间时间参数化、
+  Dora 父子 Action 编排、取消传播及最终残差检查。
+
+## 职责范围
+
+Motion 决定配置的运动学组如何到达关节或笛卡尔目标，
+不承担物体操作语义、硬件协议、电机闭环或底层 `JointCommand` 生成。
+
+完整 Piper 仿真对象联调示例见 `examples/piper_fake_plant/`。
+
+## 开发
+
+使用 Python 3.12 和 `uv`：
+
+```bash
+uv sync --frozen --all-groups
+PYTHONPATH=src uv run pytest -q
+```
+
+`PYTHONPATH=src` 暴露 `src/forge_tool` 中内置的 Tool 协议；来源见 `THIRD_PARTY_NOTICES.md`。
+可选独立可执行文件通过 `scripts/build_pyinstaller.sh` 构建。
+
+## 许可证
+
+本仓库使用 [Apache License 2.0](LICENSE)。运行时依赖不随源码仓库分发，
+保留各自许可证，详见 [NOTICE](NOTICE) 与 [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md)。
+发布独立可执行文件前审查完整打包制品。