MCPSever

A reusable MCP server intended for deployment on Fly.io. It exposes utility tools that can be connected to from other projects or production AI clients.

Available tools

• get_weather(location) - current weather for a city via OpenWeather.

• tavily_search(query) - web search via Tavily.

• calculate(expression) - safe math evaluation.

• current_time(timezone_name) - current time in an IANA timezone.

• convert_time(datetime_text, from_timezone, to_timezone) - timezone conversion.

• generate_uuid(count) - UUID v4 generation.

• generate_password(length, include_symbols, include_numbers) - strong password generation.

• analyze_text(text) - character, word, line, sentence, and paragraph counts.

• transform_text(text, operation) - upper, lower, title, slug, snake, kebab, reverse.

• extract_urls(text) - URL extraction.

• hash_text(text, algorithm) - md5, sha1, sha256, or sha512 hash.

• fetch_url(url) - fetch a public HTTP/HTTPS URL with local/private hosts blocked.

• validate_json(value) - validate JSON and report parse errors.

• format_json(value, indent, sort_keys) - pretty-print or minify JSON.

• base64_encode(text) - Base64 encode UTF-8 text.

• base64_decode(value) - Base64 decode UTF-8 text.

• url_encode(text, safe) - URL encode text.

• url_decode(value) - URL decode text.

• decode_jwt(token) - inspect JWT header and payload without signature verification.

• test_regex(pattern, text, flags) - test regular expressions and list matches.

• format_sql(sql) - lightweight SQL formatting.

• http_request(url, method, headers_json, body, timeout_seconds) - make public HTTP requests with private/local hosts blocked.

Related MCP server: mcp-server-demo

Configuration

Required environment variables for API-backed tools:

OPENWEATHER_API_KEY=
TAVILY_API_KEY=
MCP_API_KEY=

MCP_API_KEY protects all MCP/tool routes. / and /health remain public so Fly.io health checks can work. If MCP_API_KEY is not set, authentication is disabled for local development.

Local run

uv sync
uv run uvicorn app.main:app --host 0.0.0.0 --port 8000

Health check:

http://localhost:8000/health

Fly.io deploy

fly secrets set OPENWEATHER_API_KEY=your_openweather_key
fly secrets set TAVILY_API_KEY=your_tavily_key
fly secrets set MCP_API_KEY=your_long_random_server_key
fly deploy

After deployment, use the Fly.io app URL as your hosted MCP server endpoint. Pass the key from clients with either:

X-API-Key: your_long_random_server_key

or:

Authorization: Bearer your_long_random_server_key