TinyFn — MCP server for Claude Code: features and setup
TinyFn gives AI agents callable tools for calculations, data conversion, validation, hashing, and date operations. Use it when a task needs a computed result rather than a model-generated guess.
claude mcp add --transport http tinyfn https://api.tinyfn.io/mcp/all/What TinyFn does
TinyFn exposes more than 500 tools through a remote MCP server. Its functions cover arithmetic, unit conversions, string and identifier checks, hashing, encoding, and date calculations. It can also generate UUIDs and passwords. These operations run through dedicated tools rather than relying on the language model to work out each result itself.
The service runs remotely, so a local npx or Docker installation is unnecessary. You need an API key and must pass it through the X-API-Key header in the client configuration. Claude Code can connect to https://api.tinyfn.io/mcp/all/ to access the complete tool set. Other clients can use category-specific endpoints to stay within their tool limits.
The free tier includes 100 requests per month without requiring a credit card. Client limits matter: Cursor and Windsurf have smaller tool budgets, so the project recommends selecting focused categories for those environments. A configured connection still needs a valid API key for authorization.
What it helps with
- Calculate a percentage of a given number
- Convert temperatures or distances between units
- Validate an email address or UUID
- Generate a SHA-256 digest from a string
- Find the interval between dates or create a UUID
Example prompts for the agent
- Calculate 17% of 4847 using an available TinyFn tool.
- Check whether [email protected] has a valid email format.
- Generate a SHA-256 hash for the string my-secret-string.
How to install TinyFn
Platform CLI: remote server
claude mcp add --transport http tinyfn https://api.tinyfn.io/mcp/all/Platform CLI: remote server
codex mcp add tinyfn --url https://api.tinyfn.io/mcp/all/Config file
{
"mcpServers": {
"tinyfn": {
"url": "https://api.tinyfn.io/mcp/all/"
}
}
}Config file
{
"servers": {
"tinyfn": {
"type": "http",
"url": "https://api.tinyfn.io/mcp/all/"
}
}
}Platform CLI: remote server
gemini mcp add -t http tinyfn https://api.tinyfn.io/mcp/all/Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about TinyFn
How do I install TinyFn in Claude Code?
Get an API key from https://tinyfn.io, then run claude mcp add --transport http tinyfn https://api.tinyfn.io/mcp/all/. To authenticate the connection, add the X-API-Key header to the MCP configuration.
What does TinyFn do?
TinyFn is a remote MCP server offering more than 500 tools for arithmetic, conversions, data validation, hashing, encoding, and date calculations. An AI agent can call these functions for deterministic operations instead of calculating or checking values on its own.
Does TinyFn require an API key?
Yes. Obtain a key from https://tinyfn.io and provide it through the X-API-Key header in your MCP client configuration. The free tier covers 100 requests per month.
