windsurf-sdk-patterns

Windsurf Configuration Patterns

Overview

Production-ready configuration patterns for Windsurf IDE: rules files, workspace rules with trigger modes, MCP server integration, and Cascade prompt engineering.

Prerequisites

• Windsurf authenticated and operational
• Understanding of Cascade Write vs Chat modes
• Project with established coding conventions

Instructions

Step 1: Root-Level .windsurfrules (Permanent Context)

The .windsurfrules file is the single highest-impact configuration for Cascade output quality. It provides persistent context every session.

<!-- .windsurfrules -->

# Project: payments-api

## Stack
- Runtime: Node.js 20 LTS
- Language: TypeScript 5.x (strict, noUncheckedIndexedAccess)
- Framework: Fastify v4
- ORM: Drizzle (PostgreSQL)
- Validation: zod
- Testing: Vitest
- Linting: Biome

## Architecture Rules
- Route handlers in src/routes/ — no business logic
- Business logic in src/services/ — never throw, use Result<T,E>
- Database queries in src/repositories/ — Drizzle only
- Shared types in src/types/ — all exported with JSDoc

## Don't
- Don't use `any` type
- Don't use default exports
- Don't use class-based patterns (use functions + closures)
- Don't modify files in migrations/ without explicit request
- Don't use deprecated APIs: my_old_helper, legacyAuth

## Testing
- Unit tests for every service method
- Integration tests for every route handler
- No mocking repositories in integration tests
- Use test fixtures from tests/fixtures/

Limits: 6,000 characters per rules file. 12,000 total (global + workspace combined).

Step 2: Workspace Rules with Trigger Modes

Create granular rules in .windsurf/rules/ with YAML frontmatter:

<!-- .windsurf/rules/testing.md -->
---
trigger: glob
globs: **/*.test.ts, **/*.spec.ts
---
All test files must:
- Use describe/it blocks (not test())
- Mock external API calls with msw
- Assert both success and error paths
- Include at least one snapshot test for UI components
- Use factory functions from tests/fixtures/ for test data

<!-- .windsurf/rules/api-routes.md -->
---
trigger: glob
globs: src/routes/**/*.ts
---
API route handlers must:
- Validate input with zod schema before processing
- Return consistent error format: { error: string, code: string, statusCode: number }
- Include request ID in all log lines
- Never call database directly — use repository layer

<!-- .windsurf/rules/security.md -->
---
trigger: model_decision
description: Apply when code touches authentication, authorization, or secrets
---
Security requirements:
- Never log secrets, tokens, or PII
- Use parameterized queries (never string interpolation for SQL)
- Validate JWT tokens with jose library
- Rate limit all public endpoints
- CORS: explicit origin whitelist, never wildcard in production

<!-- .windsurf/rules/migrations.md -->
---
trigger: manual
---
Database migration rules (activate with @migrations):
- Always create reversible migrations (up + down)
- Never drop columns in production — deprecate first
- Add indexes for any new foreign key columns
- Test migration on a copy of production data first

Step 3: MCP Server Configuration

Connect external tools to Cascade via Model Context Protocol:

// ~/.codeium/windsurf/mcp_config.json
{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "${GITHUB_TOKEN}"
      }
    },
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"],
      "env": {
        "DATABASE_URL": "${DATABASE_URL}"
      }
    },
    "memory": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-memory"]
    }
  }
}

Enable in Windsurf Settings > Cascade > Model Context Protocol (MCP).

Tool limit: Cascade supports max 100 MCP tools total across all servers. Disable unused tools in each MCP's settings page.

Step 4: Effective Cascade Prompt Patterns

GOOD prompts (specific, scoped):
"In src/services/payment.ts, add a refundPayment method that calls
Stripe's refund API. Handle partial refunds. Return Result<Refund, PaymentError>."

"@src/routes/users.ts Add input validation using the UserCreateSchema
from src/types/user.ts. Return 400 with field-level errors."

BAD prompts (vague, unscoped):
"Add validation to the API"
"Refactor the codebase"
"Make it better"

Error Handling

Examples

Global Rules (Apply to All Projects)

<!-- ~/.windsurf/global_rules.md (6,000 char limit) -->
- Always use English for code comments and commit messages
- Prefer functional programming patterns over OOP
- Write self-documenting code; add comments only for "why", not "what"
- When suggesting terminal commands, explain what they do
- Never suggest installing global npm packages

Project Health Check

# Verify Windsurf config exists
ls -la .windsurfrules .codeiumignore .windsurf/rules/ 2>/dev/null

Resources

• Windsurf Rules Directory
• Cascade Memories
• MCP Integration

Next Steps

Apply patterns in windsurf-core-workflow-a for real-world Cascade usage.