Using TinyFn MCP with Windsurf IDE

Windsurf IDE's Cascade AI assistant is powerful, but it can struggle with precise calculations, validations, and encodings. This guide shows you how to supercharge Windsurf with TinyFn's 500+ deterministic tools via MCP.

Windsurf MCP Support

Windsurf IDE, developed by Codeium, includes built-in support for the Model Context Protocol (MCP). This allows Cascade, Windsurf's AI assistant, to access external tools during coding sessions.

With MCP integration, Cascade can:

• Call external APIs for precise calculations
• Validate data formats using RFC-compliant validators
• Generate hashes, UUIDs, and encoded strings
• Convert between units and formats
• Process JSON, dates, and other structured data

Configuration Steps

Step 1: Get Your TinyFn API Key

If you don't have one yet, sign up at tinyfn.io to get your free API key.

Step 2: Open Windsurf Settings

In Windsurf, open the Command Palette (Cmd+Shift+P on Mac or Ctrl+Shift+P on Windows/Linux) and search for "Windsurf Settings" or navigate to File > Preferences > Windsurf Settings.

Step 3: Configure MCP Server

Find the MCP configuration section and add TinyFn as a server:

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

Step 4: Restart Windsurf

After saving the configuration, restart Windsurf to load the MCP tools. You should see TinyFn tools available in Cascade's tool list.

Alternative: Category-Specific Endpoints

If you want to limit which tools are available, use category-specific endpoints:

{
  "mcpServers": {
    "tinyfn-dev": {
      "url": "https://api.tinyfn.io/mcp/encode/",
      "headers": { "X-API-Key": "your-api-key" }
    },
    "tinyfn-hash": {
      "url": "https://api.tinyfn.io/mcp/hash/",
      "headers": { "X-API-Key": "your-api-key" }
    },
    "tinyfn-validate": {
      "url": "https://api.tinyfn.io/mcp/validate/",
      "headers": { "X-API-Key": "your-api-key" }
    }
  }
}

Available Tools

Here are the most useful TinyFn tools for coding workflows in Windsurf:

Encoding & Decoding

Hashing & Security

JSON & Data

Workflow Examples

Example 1: Generating Test Data

Create a test user object with a valid UUID,
a SHA-256 hashed password, and today's timestamp in ISO format.

With TinyFn MCP, Cascade will call the appropriate tools:

// Using generate/uuid, hash/sha256, and datetime/now tools

const testUser = {
  id: "f47ac10b-58cc-4372-a567-0e02b2c3d479",  // Real UUID from tool
  passwordHash: "5e884898da28047d9166957...",   // Real SHA-256 hash
  createdAt: "2025-01-30T14:32:15.000Z"         // Actual timestamp
};

Example 2: Validating API Input

Write a function that validates this JSON config
and checks if the email is valid:
{"email": "test@example.com", "count": 5}

// First, let me verify the JSON is valid...
// Using json/validate: ✓ Valid JSON

// Now checking the email format...
// Using validate/email: ✓ "test@example.com" is valid

function validateConfig(config) {
  // JSON already validated as structurally correct
  // Email validated as RFC 5322 compliant
  return {
    valid: true,
    email: config.email,
    count: config.count
  };
}

Example 3: Working with Timestamps

Convert the Unix timestamp 1706627535 to a readable date
and calculate how many days ago it was.

// Using datetime/from-unix and datetime/diff tools

The timestamp 1706627535 corresponds to:
January 30, 2024 at 2:32:15 PM UTC

That was exactly 365 days ago from today.

Tips for Best Results

1. Be specific in prompts: Mention when you need "real" or "valid" values. Cascade will know to use tools instead of generating fake data.
2. Ask for verification: Phrases like "validate this JSON" or "check if this email is valid" trigger tool usage.
3. Request precise formats: "Give me the exact SHA-256 hash" signals that Cascade should use a tool, not guess.
4. Use for debugging: Ask Cascade to decode JWT tokens or parse timestamps when debugging - it'll use TinyFn for accurate results.