Updated doc for file-related agent API

docs/Agent-API.md

@@ -4,17 +4,17 @@ The Agent API is organized into 4 types of resources that can be accessed by the
 
 - Meshes
 - Endpoints
-- Files
 - Apps
+- Files
 
 A **Mesh** is the root resource of everything. It contains a configuration providing required information for joining a mesh.
 
 **Endpoints** are automatically registered to the mesh when an agent joins in, and discovered by agents on other endpoints in the same mesh.
 
-**Files** can be stored in the mesh (on multiple endpoints) and accessible from other endpoints, or stored locally (in the local database) for private access only.
-
 **Apps** are bundles of script files written in [PipyJS](https://github.com/flomesh-io/pipy). They can be installed locally or published to the mesh for remote installation on other endpoints. Some builtin apps, including `tunnel`, `proxy` and `terminal`, are available for use without the need of an installation.
 
+**Files** can be stored in the mesh (on multiple endpoints) and accessible from other endpoints, or stored locally (in the local database) for private access only.
+
 In addtion to the above resource types, apps can provide extra resource types via the Agent API. For example, the `tunnel` app provides 2 types of resources:
 
 - Inbound
@@ -142,6 +142,34 @@ POST /api/meshes/{meshName}/endpoints/{uuid}/apps/{provider}/{name[@tag]}
 DELETE /api/meshes/{meshName}/endpoints/{uuid}/apps/{provider}/{name[@tag]}
 ```
 
+## File
+
+GET returns metainfo:
+
+```json
+{
+    "size": 1024,
+    "time": 1721711888888,
+    "hash": "012345678abcdef",
+    "sources": [
+        "endpoint-id-1",
+        "endpoint-id-2"
+    ]
+}
+```
+
+Or returns raw binary content for `/file-data` based paths.
+
+Paths and methods:
+
+```
+GET /api/meshes/{meshName}/files
+GET /api/meshes/{meshName}/files/{pathname}
+GET /api/meshes/{meshName}/file-data/{pathname}
+POST /api/meshes/{meshName}/file-data/{pathname}
+DELETE /api/meshes/{meshName}/file-data/{pathname}
+```
+
 ## Inbound
 
 GET returns: