"""
Configuration module for Canvas LMS MCP Server.
Handles loading of:
- Environment variables from .env (REQUIRED)
- Test hints from test_hints.json (OPTIONAL)
Security: Fails immediately if .env is missing or token is not set.
"""
import json
import os
import sys
from pathlib import Path
from typing import Any
from dotenv import load_dotenv
from pydantic import BaseModel, Field, field_validator
class CanvasConfig(BaseModel):
"""Canvas API configuration with validation."""
api_token: str = Field(..., description="Canvas API Bearer Token")
base_url: str = Field(
default="https://texastech.instructure.com",
description="Canvas instance base URL",
)
@field_validator("api_token")
@classmethod
def validate_token(cls, v: str) -> str:
"""Ensure token is not empty or placeholder."""
if not v or v.strip() == "":
raise ValueError("CANVAS_API_TOKEN cannot be empty")
if v == "your_canvas_api_token_here":
raise ValueError(
"CANVAS_API_TOKEN is still set to placeholder. "
"Please update .env with your actual Canvas API token."
)
return v.strip()
@field_validator("base_url")
@classmethod
def validate_url(cls, v: str) -> str:
"""Ensure URL is valid and doesn't have trailing slash."""
v = v.strip().rstrip("/")
if not v.startswith("https://"):
raise ValueError("CANVAS_BASE_URL must start with https://")
return v
class TestHints(BaseModel):
"""Optional test hints for targeted testing."""
valid_course_ids: list[int] = Field(default_factory=list)
test_assignment_id: int | None = None
test_module_id: int | None = None
test_discussion_id: int | None = None
def load_env_config() -> CanvasConfig:
"""
Load Canvas configuration from environment variables.
Raises:
SystemExit: If .env file is missing or required variables are not set.
Returns:
CanvasConfig: Validated configuration object.
"""
# Determine project root (where .env should be)
project_root = Path(__file__).parent
# Look for .env file
env_file = project_root / ".env"
if not env_file.exists():
print("=" * 60, file=sys.stderr)
print("CRITICAL ERROR: .env file not found!", file=sys.stderr)
print("=" * 60, file=sys.stderr)
print(f"Expected location: {env_file}", file=sys.stderr)
print("", file=sys.stderr)
print("To fix this:", file=sys.stderr)
print("1. Copy .env.example to .env", file=sys.stderr)
print("2. Add your Canvas API token to .env", file=sys.stderr)
print("", file=sys.stderr)
print("Example .env contents:", file=sys.stderr)
print(" CANVAS_API_TOKEN=your_actual_token_here", file=sys.stderr)
print(" CANVAS_BASE_URL=https://texastech.instructure.com", file=sys.stderr)
print("=" * 60, file=sys.stderr)
sys.exit(1)
# Load environment variables from .env
load_dotenv(env_file)
# Get values from environment
api_token = os.getenv("CANVAS_API_TOKEN", "")
base_url = os.getenv("CANVAS_BASE_URL", "https://texastech.instructure.com")
try:
return CanvasConfig(api_token=api_token, base_url=base_url)
except ValueError as e:
print("=" * 60, file=sys.stderr)
print("CONFIGURATION ERROR", file=sys.stderr)
print("=" * 60, file=sys.stderr)
print(str(e), file=sys.stderr)
print("=" * 60, file=sys.stderr)
sys.exit(1)
def load_test_hints() -> TestHints:
"""
Load test hints from test_hints.json.
This is optional - if the file doesn't exist or is invalid,
returns empty hints with a warning.
Returns:
TestHints: Test hint configuration (may be empty).
"""
project_root = Path(__file__).parent
hints_file = project_root / "test_hints.json"
if not hints_file.exists():
print(
"NOTE: test_hints.json not found. "
"Some tests may be skipped. Create test_hints.json with valid course IDs for full testing.",
file=sys.stderr,
)
return TestHints()
try:
with open(hints_file, "r") as f:
data = json.load(f)
return TestHints(**data)
except json.JSONDecodeError as e:
print(
f"WARNING: test_hints.json contains invalid JSON: {e}. Using empty hints.",
file=sys.stderr,
)
return TestHints()
except Exception as e:
print(
f"WARNING: Could not load test_hints.json: {e}. Using empty hints.",
file=sys.stderr,
)
return TestHints()
def get_api_headers(token: str) -> dict[str, str]:
"""
Generate standard headers for Canvas API requests.
Args:
token: Canvas API Bearer token.
Returns:
dict: Headers dictionary for httpx requests.
"""
return {
"Authorization": f"Bearer {token}",
"Content-Type": "application/json",
"Accept": "application/json",
}
# Module-level constants for easy import
PROJECT_ROOT = Path(__file__).parent
DEFAULT_PER_PAGE = 50
MAX_PER_PAGE = 100
def get_config() -> tuple[CanvasConfig, TestHints]:
"""
Convenience function to load all configuration at once.
Returns:
tuple: (CanvasConfig, TestHints)
"""
return load_env_config(), load_test_hints()
if __name__ == "__main__":
# Test configuration loading
print("Testing configuration loading...")
config, hints = get_config()
print(f"✅ Base URL: {config.base_url}")
print(f"✅ Token loaded: {'*' * 8}...{config.api_token[-4:]}")
print(f"✅ Course IDs in hints: {hints.valid_course_ids}")
