TinyFn

TinyFn MCP Server

🧮 Give your AI agent 500+ deterministic tools

Stop hallucinating math. Start getting correct answers.

Quick Start • Servers • Examples • Pricing • Docs • Support

🎉 Free Tier Available! 100 requests/month FREE — no credit card required Get your free API key →

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The Problem

LLMs are great at reasoning. They're terrible at math.

Ask any AI assistant to compute 17% of 4,847 and you'll get a confident, wrong answer. Ask it to validate an email with regex, generate a SHA-256 hash, or convert timezones — same story. LLMs hallucinate on deterministic tasks.

TinyFn is a Model Context Protocol (MCP) server that gives your AI assistant 500+ tools that always return the correct answer. Math, conversions, validations, hashing, date arithmetic — the boring stuff, done right.

🧮 500+ Tools Math, strings, dates, and much more 🎯 Zero Hallucinations Deterministic results every single time ⚡ No Installation Remote MCP server zero setup 🔌 Works Everywhere Claude, Cursor, Windsurf, any MCP client

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🖥️ Works With Your Tools

TinyFn runs as a remote MCP server — no npx, no Docker, no local install. Just add the URL to your config.

💡 Why category servers? Most AI clients limit the number of tools. TinyFn splits 500+ tools across 12 focused servers so you can pick exactly what you need.

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✅ Example Queries That Just Work

Once connected, just ask your AI assistant in plain language:

Math & Numbers

• ✅ *"Is 7919 a prime number?"*
• ✅ *"What's 17% of 4,847?"*
• ✅ *"Calculate the factorial of 12"*

Conversions

• ✅ *"Convert 72°F to Celsius"*
• ✅ *"How many miles is 100 kilometers?"*
• ✅ *"Convert #3B82F6 to RGB values"*

Validation

• ✅ *"Is user@example.com a valid email address?"*
• ✅ *"Validate this credit card number: 4111111111111111"*
• ✅ *"Is 550e8400-e29b-41d4-a716-446655440000 a valid UUID?"*

Encoding & Hashing

• ✅ *"Base64 encode 'Hello, World!'"*
• ✅ *"Generate a SHA-256 hash of 'my-secret-string'"*
• ✅ *"URL encode 'hello world & goodbye'"*

Date & Time

• ✅ *"How many days between January 15 and March 22?"*
• ✅ *"What's the current Unix timestamp?"*
• ✅ *"Is 2024 a leap year?"*

Generators

• ✅ *"Generate a UUID"*
• ✅ *"Create a secure 20-character password"*
• ✅ *"Roll 3 six-sided dice"*

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⚡ Quick Start

1. Get your free API key at [tinyfn.io](https://tinyfn.io) (takes 10 seconds)

2. Add TinyFn to your MCP client:

Claude Code

Claude Code supports Tool Search, so you can use the full server with all 500+ tools:

{

"mcpServers": { "tinyfn": { "url": "https://api.tinyfn.io/mcp/all/", "headers": { "X-API-Key": "tf_live_YOUR_KEY_HERE" } } } }

Add this to ~/.claude/settings.json or use claude mcp add.

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{

"mcpServers": { "tinyfn-math": { "url": "https://api.tinyfn.io/mcp/math/", "headers": { "X-API-Key": "tf_live_YOUR_KEY_HERE" } }, "tinyfn-validate": { "url": "https://api.tinyfn.io/mcp/validate/", "headers": { "X-API-Key": "tf_live_YOUR_KEY_HERE" } } } }

Tip: Claude Desktop supports ~100 tools. Add 2–3 category servers based on your workflow.

Cursor & Windsurf

These platforms have a ~40 tool limit. Pick 1–2 focused servers:

{

"mcpServers": { "tinyfn-validate": { "url": "https://api.tinyfn.io/mcp/validate/", "headers": { "X-API-Key": "tf_live_YOUR_KEY_HERE" } } } }

Recommended for Cursor/Windsurf: validate (15 tools), hash (18 tools), encode (20 tools), convert (42 tools).

Continue.dev

{

"experimental": { "mcpServers": [ { "name": "tinyfn-math", "url": "https://api.tinyfn.io/mcp/math/", "headers": { "X-API-Key": "tf_live_YOUR_KEY_HERE" } } ] } }

3. Start asking questions. Your AI now has deterministic tools for math, conversions, validation, and more.

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📡 Available MCP Servers

All servers use base URL https://api.tinyfn.io. Pick the categories you need:

⚠️ Important: All URLs must end with a trailing / or requests will return 404 errors.

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🛠️ Tool Categories

🔢 Math & Numbers — 52 tools

📝 String Operations — 33 tools

✅ Validation — 15 tools

🔄 Conversions — 42 tools

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