Update cli

AGENTS.md

@@ -16,6 +16,7 @@ Use `just` for all development tasks:
 | `just console` | Run Textual devtools console |
 | `just get-card` | Fetch agent card (CLI) |
 | `just send` | Send message to agent (CLI) |
+| `just validate` | Validate agent card (CLI) |
 | `just version` | Show current version |
 | `just bump` | Bump version (patch, minor, major) |
 | `just tag` | Create git tag for current version |
@@ -27,8 +28,9 @@ Use `just` for all development tasks:
 handler/
 ├── src/a2a_handler/     # Main package
 │   ├── _version.py      # Version string
-│   ├── cli.py           # CLI (click)
+│   ├── cli.py           # CLI (rich-click)
 │   ├── client.py        # A2A protocol client (a2a-sdk)
+│   ├── validation.py    # Agent card validation utilities
 │   ├── server.py        # A2A server agent (google-adk, litellm)
 │   ├── tui.py           # TUI application (textual)
 │   ├── common/          # Shared utilities (rich, logging)
@@ -61,7 +63,7 @@ The `a2a_handler.client` module provides A2A protocol logic:
 
 ## Key Dependencies
 
-- **CLI**: `click`
+- **CLI**: `rich-click` (enhanced `click` with rich formatting)
 - **Client**: `a2a-sdk`, `httpx`
 - **Server**: `google-adk`, `litellm`, `uvicorn`
 - **TUI**: `textual`

CONTRIBUTING.md

@@ -6,8 +6,9 @@ Handler is a single Python package (`a2a-handler`) with all modules under `src/a
 
 | Module | Description |
 |--------|-------------|
-| `cli.py` | CLI built with `click`. Entry point: `handler` |
+| `cli.py` | CLI built with `rich-click`. Entry point: `handler` |
 | `client.py` | A2A protocol client library using `a2a-sdk` |
+| `validation.py` | Agent card validation utilities |
 | `common/` | Shared utilities (logging, printing with `rich`) |
 | `server.py` | Reference A2A agent using `google-adk` + `litellm` |
 | `tui.py` | TUI application built with `textual` |
@@ -43,6 +44,7 @@ just install  # or: uv sync
 | `just console` | Run Textual devtools console |
 | `just get-card [url]` | Fetch agent card from URL |
 | `just send [url] [msg]` | Send message to agent |
+| `just validate [source]` | Validate agent card from URL or file |
 | `just version` | Show current version |
 | `just bump [level]` | Bump version (patch, minor, major) |
 | `just tag` | Create git tag for current version |

README.md

@@ -54,16 +54,44 @@ handler tui
 
 ### CLI
 
+#### Global Options
+
+```bash
+handler --verbose  # Enable verbose logging output
+handler --debug    # Enable debug logging output
+handler --help     # Show help for any command
+```
+
+#### Commands
+
 Fetch agent card from A2A server:
 
 ```bash
 handler card http://localhost:8000
+handler card http://localhost:8000 --output json  # JSON output
+```
+
+Validate an agent card from a URL or file:
+
+```bash
+handler validate http://localhost:8000             # Validate from URL
+handler validate ./agent-card.json                 # Validate from file
+handler validate http://localhost:8000 --output json  # JSON output
 ```
 
 Send a message to an A2A agent:
 
 ```bash
 handler send http://localhost:8000 "Hello World"
+handler send http://localhost:8000 "Hello" --output json    # JSON output
+handler send http://localhost:8000 "Hello" --context-id abc # Conversation continuity
+handler send http://localhost:8000 "Hello" --task-id xyz    # Reference existing task
+```
+
+Show version:
+
+```bash
+handler version
 ```
 
 ## Contributing

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "a2a-handler"
-version = "0.1.7"
+version = "0.1.8"
 description = "An A2A Protocol client TUI and CLI."
 readme = "README.md"
 requires-python = ">=3.11"
@@ -34,6 +34,7 @@ classifiers = [
 dependencies = [
     "a2a-sdk>=0.2.5",
     "click>=8.0.0",
+    "rich-click>=1.8.0",
     "google-adk>=0.5.0",
     "httpx>=0.27.0",
     "litellm>=1.0.0",