diff --git a/openwebui_cli/commands/chat.py b/openwebui_cli/commands/chat.py
index 2e1b5c3..9105823 100644
--- a/openwebui_cli/commands/chat.py
+++ b/openwebui_cli/commands/chat.py
@@ -28,6 +28,7 @@ def send(
     temperature: float | None = typer.Option(None, "--temperature", "-T", help="Temperature (0.0-2.0)"),
     max_tokens: int | None = typer.Option(None, "--max-tokens", help="Max response tokens"),
     json_output: bool = typer.Option(False, "--json", help="Output as JSON"),
+    history_file: str | None = typer.Option(None, "--history-file", help="Load conversation history from JSON file"),
 ) -> None:
     """Send a chat message."""
     obj = ctx.obj or {}
@@ -41,10 +42,38 @@ def send(
             console.print("[red]Error: Prompt required. Use -p or pipe input.[/red]")
             raise typer.Exit(2)
 
-    # Build messages
+    # Load conversation history if provided
     messages = []
-    if system:
-        messages.append({"role": "system", "content": system})
+    if history_file:
+        try:
+            from pathlib import Path
+            history_path = Path(history_file)
+            if not history_path.exists():
+                console.print(f"[red]Error: History file not found: {history_file}[/red]")
+                raise typer.Exit(2)
+
+            with open(history_path) as f:
+                history_data = json.load(f)
+                # Support both direct array and object with 'messages' key
+                if isinstance(history_data, list):
+                    messages = history_data
+                elif isinstance(history_data, dict) and "messages" in history_data:
+                    messages = history_data["messages"]
+                else:
+                    console.print("[red]Error: History file must contain array of messages or object with 'messages' key[/red]")
+                    raise typer.Exit(2)
+        except json.JSONDecodeError as e:
+            console.print(f"[red]Error: Invalid JSON in history file: {e}[/red]")
+            raise typer.Exit(2)
+        except Exception as e:
+            console.print(f"[red]Error loading history file: {e}[/red]")
+            raise typer.Exit(2)
+
+    # Build messages (add system prompt if not in history)
+    if system and not any(msg.get("role") == "system" for msg in messages):
+        messages.insert(0, {"role": "system", "content": system})
+
+    # Add current user prompt
     messages.append({"role": "user", "content": prompt})
 
     # Build request body
@@ -78,33 +107,49 @@ def send(
         ) as client:
             if body.get("stream"):
                 # Streaming response
-                with client.stream(
-                    "POST",
-                    "/api/v1/chat/completions",
-                    json=body,
-                ) as response:
-                    if response.status_code >= 400:
-                        handle_response(response)
+                try:
+                    with client.stream(
+                        "POST",
+                        "/api/v1/chat/completions",
+                        json=body,
+                    ) as response:
+                        if response.status_code >= 400:
+                            handle_response(response)
 
-                    full_content = ""
-                    for line in response.iter_lines():
-                        if line.startswith("data: "):
-                            data_str = line[6:]
-                            if data_str.strip() == "[DONE]":
-                                break
-                            try:
-                                data = json.loads(data_str)
-                                delta = data.get("choices", [{}])[0].get("delta", {})
-                                content = delta.get("content", "")
-                                if content:
-                                    print(content, end="", flush=True)
-                                    full_content += content
-                            except json.JSONDecodeError:
-                                continue
-                    print()  # Final newline
+                        full_content = ""
+                        try:
+                            for line in response.iter_lines():
+                                if line.startswith("data: "):
+                                    data_str = line[6:]
+                                    if data_str.strip() == "[DONE]":
+                                        break
+                                    try:
+                                        data = json.loads(data_str)
+                                        delta = data.get("choices", [{}])[0].get("delta", {})
+                                        content = delta.get("content", "")
+                                        if content:
+                                            print(content, end="", flush=True)
+                                            full_content += content
+                                    except json.JSONDecodeError:
+                                        # Skip malformed JSON chunks
+                                        continue
+                        except KeyboardInterrupt:
+                            # Gracefully handle Ctrl-C during streaming
+                            print()  # Newline after partial output
+                            console.print("\n[yellow]Stream interrupted by user[/yellow]")
+                            if full_content and json_output:
+                                console.print(json.dumps({"content": full_content, "interrupted": True}, indent=2))
+                            raise typer.Exit(0)
 
-                    if json_output:
-                        console.print(json.dumps({"content": full_content}, indent=2))
+                        print()  # Final newline
+
+                        if json_output:
+                            console.print(json.dumps({"content": full_content}, indent=2))
+
+                except (ConnectionError, TimeoutError) as e:
+                    console.print(f"\n[red]Connection error during streaming: {e}[/red]")
+                    console.print("[yellow]Try reducing timeout or checking network connection[/yellow]")
+                    raise typer.Exit(4)
             else:
                 # Non-streaming response
                 response = client.post("/api/v1/chat/completions", json=body)
@@ -116,6 +161,10 @@ def send(
                     content = data.get("choices", [{}])[0].get("message", {}).get("content", "")
                     console.print(content)
 
+    except KeyboardInterrupt:
+        # Handle Ctrl-C at top level
+        console.print("\n[yellow]Operation cancelled[/yellow]")
+        raise typer.Exit(0)
     except Exception as e:
         handle_request_error(e)
 
diff --git a/openwebui_cli/config.py b/openwebui_cli/config.py
index 50a4450..8030835 100644
--- a/openwebui_cli/config.py
+++ b/openwebui_cli/config.py
@@ -5,7 +5,7 @@ from pathlib import Path
 from typing import Any
 
 import yaml
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 from pydantic_settings import BaseSettings
 
 
@@ -60,14 +60,12 @@ class Config(BaseModel):
 class Settings(BaseSettings):
     """Environment-based settings that override config file."""
 
+    model_config = ConfigDict(env_prefix="", case_sensitive=False)
+
     openwebui_uri: str | None = None
     openwebui_token: str | None = None
     openwebui_profile: str | None = None
 
-    class Config:
-        env_prefix = ""
-        case_sensitive = False
-
 
 def load_config() -> Config:
     """Load configuration from file, with defaults for missing values."""
diff --git a/openwebui_cli/http.py b/openwebui_cli/http.py
index 07a6581..5581734 100644
--- a/openwebui_cli/http.py
+++ b/openwebui_cli/http.py
@@ -120,18 +120,44 @@ def handle_response(response: httpx.Response) -> dict[str, Any]:
         CLIError: For other error responses
     """
     if response.status_code == 401:
-        raise AuthError("Authentication required. Please run 'openwebui auth login'")
+        raise AuthError(
+            "Authentication required. Please run 'openwebui auth login' first.\n"
+            "If you recently logged in, your token may have expired."
+        )
     elif response.status_code == 403:
-        raise AuthError("Permission denied. Check your access rights.")
+        raise AuthError(
+            "Permission denied. This operation requires higher privileges.\n"
+            "Possible causes:\n"
+            "  - Your user role lacks required permissions\n"
+            "  - The API key doesn't have sufficient access\n"
+            "  - Try logging in again: openwebui auth login"
+        )
+    elif response.status_code == 404:
+        try:
+            error_data = response.json()
+            message = error_data.get("detail", error_data.get("message", "Resource not found"))
+        except Exception:
+            message = "Resource not found"
+        raise ServerError(
+            f"Not found: {message}\n"
+            "Check that the resource ID, model name, or endpoint is correct."
+        )
     elif response.status_code >= 500:
-        raise ServerError(f"Server error: {response.status_code} - {response.text}")
+        raise ServerError(
+            f"Server error ({response.status_code}): {response.text}\n"
+            "The OpenWebUI server encountered an error.\n"
+            "Try again in a moment, or check server logs if you're the administrator."
+        )
     elif response.status_code >= 400:
         try:
             error_data = response.json()
             message = error_data.get("detail", error_data.get("message", response.text))
         except Exception:
             message = response.text
-        raise ServerError(f"API error: {response.status_code} - {message}")
+        raise ServerError(
+            f"API error ({response.status_code}): {message}\n"
+            "Check your request parameters and try again."
+        )
 
     try:
         return response.json()
@@ -142,10 +168,25 @@ def handle_response(response: httpx.Response) -> dict[str, Any]:
 def handle_request_error(error: Exception) -> None:
     """Convert httpx errors to CLI errors."""
     if isinstance(error, httpx.ConnectError):
-        raise NetworkError(f"Could not connect to server: {error}")
+        raise NetworkError(
+            f"Could not connect to server: {error}\n"
+            "Possible solutions:\n"
+            "  - Check that OpenWebUI is running\n"
+            "  - Verify the URI: openwebui config init\n"
+            "  - Try: openwebui --uri http://localhost:8080 auth login"
+        )
     elif isinstance(error, httpx.TimeoutException):
-        raise NetworkError(f"Request timed out: {error}")
+        raise NetworkError(
+            f"Request timed out: {error}\n"
+            "Possible solutions:\n"
+            "  - Increase timeout: openwebui --timeout 60 ...\n"
+            "  - Check your network connection\n"
+            "  - The server might be overloaded"
+        )
     elif isinstance(error, httpx.RequestError):
-        raise NetworkError(f"Request failed: {error}")
+        raise NetworkError(
+            f"Request failed: {error}\n"
+            "Check your network connection and server configuration."
+        )
     else:
         raise error
diff --git a/tests/test_chat.py b/tests/test_chat.py
new file mode 100644
index 0000000..e4c5e24
--- /dev/null
+++ b/tests/test_chat.py
@@ -0,0 +1,301 @@
+"""Tests for chat commands."""
+
+import json
+from pathlib import Path
+from unittest.mock import MagicMock, Mock, patch
+
+import httpx
+import pytest
+from typer.testing import CliRunner
+
+from openwebui_cli.main import app
+
+runner = CliRunner()
+
+
+class MockStreamResponse:
+    """Mock streaming response for testing."""
+
+    def __init__(self, lines, status_code=200):
+        self.lines = lines
+        self.status_code = status_code
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        pass
+
+    def iter_lines(self):
+        """Yield lines one by one."""
+        for line in self.lines:
+            yield line
+
+
+@pytest.fixture
+def mock_config(tmp_path, monkeypatch):
+    """Mock configuration for testing."""
+    config_dir = tmp_path / "openwebui"
+    config_path = config_dir / "config.yaml"
+
+    monkeypatch.setattr("openwebui_cli.config.get_config_dir", lambda: config_dir)
+    monkeypatch.setattr("openwebui_cli.config.get_config_path", lambda: config_path)
+
+    # Create default config
+    from openwebui_cli.config import Config, save_config
+    config = Config()
+    save_config(config)
+
+    return config_path
+
+
+@pytest.fixture
+def mock_keyring(monkeypatch):
+    """Mock keyring for testing."""
+    token_store = {}
+
+    def get_password(service, key):
+        return token_store.get(f"{service}:{key}")
+
+    def set_password(service, key, password):
+        token_store[f"{service}:{key}"] = password
+
+    monkeypatch.setattr("keyring.get_password", get_password)
+    monkeypatch.setattr("keyring.set_password", set_password)
+
+
+def test_chat_send_streaming(mock_config, mock_keyring):
+    """Test streaming chat response."""
+    # Mock streaming response
+    streaming_lines = [
+        'data: {"choices": [{"delta": {"content": "Hello"}}]}',
+        'data: {"choices": [{"delta": {"content": " world"}}]}',
+        'data: {"choices": [{"delta": {"content": "!"}}]}',
+        "data: [DONE]",
+    ]
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_stream = MockStreamResponse(streaming_lines)
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_http_client.stream.return_value = mock_stream
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            ["chat", "send", "-m", "test-model", "-p", "Hello"],
+        )
+
+        assert result.exit_code == 0
+        assert "Hello world!" in result.stdout
+
+
+def test_chat_send_no_stream(mock_config, mock_keyring):
+    """Test non-streaming chat response."""
+    response_data = {
+        "choices": [
+            {
+                "message": {
+                    "content": "This is a test response"
+                }
+            }
+        ]
+    }
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_response = Mock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = response_data
+        mock_http_client.post.return_value = mock_response
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            ["chat", "send", "-m", "test-model", "-p", "Hello", "--no-stream"],
+        )
+
+        assert result.exit_code == 0
+        assert "This is a test response" in result.stdout
+
+
+def test_chat_send_with_system_prompt(mock_config, mock_keyring):
+    """Test chat with system prompt."""
+    response_data = {
+        "choices": [
+            {
+                "message": {
+                    "content": "Response with system prompt"
+                }
+            }
+        ]
+    }
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_response = Mock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = response_data
+        mock_http_client.post.return_value = mock_response
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            [
+                "chat", "send",
+                "-m", "test-model",
+                "-p", "Hello",
+                "-s", "You are a helpful assistant",
+                "--no-stream"
+            ],
+        )
+
+        assert result.exit_code == 0
+
+
+def test_chat_send_with_history_file(tmp_path, mock_config, mock_keyring):
+    """Test chat with history file."""
+    # Create history file
+    history_file = tmp_path / "history.json"
+    history = [
+        {"role": "user", "content": "What is 2+2?"},
+        {"role": "assistant", "content": "4"},
+    ]
+    with open(history_file, "w") as f:
+        json.dump(history, f)
+
+    response_data = {
+        "choices": [
+            {
+                "message": {
+                    "content": "Continuing conversation"
+                }
+            }
+        ]
+    }
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_response = Mock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = response_data
+        mock_http_client.post.return_value = mock_response
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            [
+                "chat", "send",
+                "-m", "test-model",
+                "-p", "What about 3+3?",
+                "--history-file", str(history_file),
+                "--no-stream"
+            ],
+        )
+
+        assert result.exit_code == 0
+
+
+def test_chat_send_stdin(mock_config, mock_keyring):
+    """Test chat with stdin input."""
+    response_data = {
+        "choices": [
+            {
+                "message": {
+                    "content": "Response from stdin"
+                }
+            }
+        ]
+    }
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_response = Mock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = response_data
+        mock_http_client.post.return_value = mock_response
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            ["chat", "send", "-m", "test-model", "--no-stream"],
+            input="Hello from stdin\n",
+        )
+
+        assert result.exit_code == 0
+
+
+def test_chat_send_json_output(mock_config, mock_keyring):
+    """Test chat with JSON output format."""
+    streaming_lines = [
+        'data: {"choices": [{"delta": {"content": "Test"}}]}',
+        "data: [DONE]",
+    ]
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_stream = MockStreamResponse(streaming_lines)
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_http_client.stream.return_value = mock_stream
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            ["chat", "send", "-m", "test-model", "-p", "Hello", "--json"],
+        )
+
+        assert result.exit_code == 0
+        assert "content" in result.stdout
+
+
+def test_chat_send_with_rag_context(mock_config, mock_keyring):
+    """Test chat with RAG file and collection context."""
+    response_data = {
+        "choices": [
+            {
+                "message": {
+                    "content": "Response with RAG context"
+                }
+            }
+        ]
+    }
+
+    with patch("openwebui_cli.commands.chat.create_client") as mock_client:
+        mock_http_client = MagicMock()
+        mock_http_client.__enter__.return_value = mock_http_client
+        mock_http_client.__exit__.return_value = None
+        mock_response = Mock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = response_data
+        mock_http_client.post.return_value = mock_response
+        mock_client.return_value = mock_http_client
+
+        result = runner.invoke(
+            app,
+            [
+                "chat", "send",
+                "-m", "test-model",
+                "-p", "Search my docs",
+                "--file", "file-123",
+                "--collection", "coll-456",
+                "--no-stream"
+            ],
+        )
+
+        assert result.exit_code == 0
+        # Verify the request was made with files context
+        call_args = mock_http_client.post.call_args
+        assert call_args is not None
+        request_body = call_args.kwargs["json"]
+        assert "files" in request_body
+        assert len(request_body["files"]) == 2