Merge pull request #62 from langbot-app/feat/new-plugin

Feat/new plugin

docs/en/plugin/dev/components/tool.md

@@ -0,0 +1,172 @@
+# Component: Tool
+
+LangBot's built-in Local Agent calls tools to interact with the outside world during execution. Currently, adding tools is supported through both plugins and MCP.
+
+## Adding Tool Components
+
+A single plugin can contain any number of tools. Execute the command `lbp comp Tool` in the plugin directory and follow the prompts to enter the tool configuration.
+
+```bash
+➜  HelloPlugin > lbp comp Tool
+Generating component Tool...
+Tool name: get_weather_alerts
+Tool description: Get weather alerts for a US state.
+Component Tool generated successfully.
+组件 Tool 生成成功。
+```
+
+This will generate `get_weather_alerts.yaml` and `get_weather_alerts.py` files in the `components/tools/` directory. The `.yaml` file defines the basic information for the tool, and the `.py` file is the tool handler:
+
+```bash
+➜  HelloPlugin > tree
+...
+├── components
+│   ├── __init__.py
+│   └── tools
+│       ├── __init__.py
+│       ├── get_weather_alerts.py
+│       └── get_weather_alerts.yaml
+...
+```
+
+## Manifest File: Tool
+
+```yaml
+apiVersion: v1  # Do not modify
+kind: Tool  # Do not modify
+metadata:
+  name: get_weather_alerts  # Tool name, for LLM recognition
+  label:
+    en_US: GetWeatherAlerts  # Tool display name, shown in LangBot UI, supports multilingual
+    zh_Hans: GetWeatherAlerts
+  description:
+    en_US: 'Get weather alerts for a US state.'  # Tool description, shown in LangBot UI, supports multilingual. Optional
+    zh_Hans: '获取美国某个州的天气预警'
+spec:
+  parameters: []  # Tool parameters, values generated by LLM based on conversation context
+  llm_prompt: 'Get weather alerts for a US state.'  # Tool prompt, for LLM to determine whether to call this tool
+execution:
+  python:
+    path: get_weather_alerts.py  # Tool handler, do not modify
+    attr: GetWeatherAlerts  # Tool handler class name, matches the class name in get_weather_alerts.py
+```
+
+## Plugin Processing
+
+The following code is generated by default (components/tools/<tool_name>.py). You need to implement the calling and return logic for this tool in the `call` method of the `GetWeatherAlerts` class.
+
+```python
+# Auto generated by LangBot Plugin SDK.
+# Please refer to https://docs.langbot.app/en/plugin/dev/tutor.html for more details.
+from __future__ import annotations
+
+from typing import Any
+
+from langbot_plugin.api.definition.components.tool.tool import Tool
+
+
+class GetWeatherAlerts(Tool):
+
+    async def call(self, params: dict[str, Any]) -> dict[str, Any]:
+        """Fill your tool code here"""
+        return {}
+```
+
+In the `call` method, implement this tool:
+
+:::info
+The weather retrieval tool example comes from MCP's [Server Writing Example](https://modelcontextprotocol.io/quickstart/server).
+:::
+
+```python
+from __future__ import annotations
+
+from typing import Any
+
+from langbot_plugin.api.definition.components.tool.tool import Tool
+import httpx
+
+# Constants
+NWS_API_BASE = "https://api.weather.gov"
+USER_AGENT = "weather-app/1.0"
+
+
+async def make_nws_request(url: str) -> dict[str, Any] | None:
+    """Make a request to the NWS API with proper error handling."""
+    headers = {
+        "User-Agent": USER_AGENT,
+        "Accept": "application/geo+json"
+    }
+    async with httpx.AsyncClient() as client:
+        try:
+            response = await client.get(url, headers=headers, timeout=30.0)
+            response.raise_for_status()
+            return response.json()
+        except Exception:
+            return None
+
+def format_alert(feature: dict) -> str:
+    """Format an alert feature into a readable string."""
+    props = feature["properties"]
+    return f"""
+Event: {props.get('event', 'Unknown')}
+Area: {props.get('areaDesc', 'Unknown')}
+Severity: {props.get('severity', 'Unknown')}
+Description: {props.get('description', 'No description available')}
+Instructions: {props.get('instruction', 'No specific instructions provided')}
+"""
+
+class GetWeatherAlerts(Tool):
+
+    async def call(self, params: dict[str, Any]) -> dict[str, Any]:
+        """Fill your tool code here"""
+        state = params.get("state", "CA")
+
+        url = f"{NWS_API_BASE}/alerts/active/area/{state}"
+        data = await make_nws_request(url)
+
+        if not data or "features" not in data:
+            return "Unable to fetch alerts or no alerts found."
+
+        if not data["features"]:
+            return "No active alerts for this state."
+
+        alerts = [format_alert(feature) for feature in data["features"]]
+        return "\n---\n".join(alerts)
+```
+
+In this tool, we need to get the `state` parameter from `params` and call the NWS API to get weather alerts for that state, so we need to define the `state` parameter in the `parameters` of the manifest file.
+
+The `parameters` format follows [JSON Schema](https://json-schema.org/docs), is supported by [OpenAI Function Calling feature](https://platform.openai.com/docs/guides/function-calling#defining-functions), and its root type is fixed as `type: object`. Please add parameters in `properties` and add required parameter descriptions in `required`.
+
+```yaml
+...
+spec:
+  parameters:
+    type: object  # Do not modify
+    properties:  # Do not modify, add parameters here
+      state:
+        type: string
+        description: 'Two-letter US state code (e.g. CA, NY)'
+    required:  # Add required parameter descriptions here
+      - state
+...
+```
+
+This tool also uses the `httpx` library, so we need to add the `httpx` dependency in `requirements.txt` in the plugin directory.
+
+```txt
+# HelloPlugin/requirements.txt
+langbot-plugin  # Already exists by default
+httpx
+```
+
+Now execute the command `lbp run` in the plugin directory to start debugging. Configure a model that supports tool calling in LangBot and select to use that model on the corresponding pipeline to use this tool.
+
+<img width="600" src="/assets/image/zh/plugin/dev/components/tool_use_in_chat.png" />
+
+## What's Next
+
+You have learned the basic usage of tools. Next, you can:
+
+- Check out [Plugin Common APIs](/en/plugin/dev/apis/common)