building-mcp-server-on-cloudflare
Builds remote MCP (Model Context Protocol) servers on Cloudflare Workers with tools, OAuth authentication, and production deployment. Generates server code, configures auth providers, and deploys to Workers. Use when: user wants to "build MCP server", "create MCP tools", "remote MCP", "deploy MCP", add "OAuth to MCP", or mentions Model Context Protocol on Cloudflare. Also triggers on "MCP authentication" or "MCP deployment". Biases towards retrieval from Cloudflare docs over pre-trained knowledge.
- Installs
- 161
- Last 24h
- —
- Trending rank
- —
- Security
- Not audited
Install
Works with every agent the skills CLI supports.
npx skills add https://developers.cloudflare.com --skill building-mcp-server-on-cloudflare- 01
Install
Run the command in your project. The CLI asks which agents to install for.
- 02
Describe the task
Ask your agent for something this skill covers. It loads building-mcp-server-on-cloudflare automatically when relevant.
- 03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.
SKILL.md
The instructions your agent reads when the skill is triggered.
Building MCP Servers on Cloudflare
Your knowledge of the MCP SDK and Cloudflare Workers integration may be outdated. Prefer retrieval over pre-training for any MCP server task.
Retrieval Sources
| Source | How to retrieve | Use for |
|---|---|---|
| MCP docs | https://developers.cloudflare.com/agents/mcp/ | Server setup, auth, deployment |
| MCP spec | https://modelcontextprotocol.io/ | Protocol spec, tool/resource definitions |
| Workers docs | Search tool or https://developers.cloudflare.com/workers/ | Runtime APIs, bindings, config |
When to Use
- User wants to build a remote MCP server
- User needs to expose tools via MCP
- User asks about MCP authentication or OAuth
- User wants to deploy MCP to Cloudflare Workers
Prerequisites
- Cloudflare account with Workers enabled
- Node.js 18+ and npm/pnpm/yarn
- Wrangler CLI (
npm install -g wrangler)
Quick Start
Option 1: Public Server (No Auth)
npm create cloudflare@latest -- my-mcp-server \
--template=cloudflare/ai/demos/remote-mcp-authless
cd my-mcp-server
npm start
Server runs at http://localhost:8788/mcp
Option 2: Authenticated Server (OAuth)
npm create cloudflare@latest -- my-mcp-server \
--template=cloudflare/ai/demos/remote-mcp-github-oauth
cd my-mcp-server
Requires OAuth app setup. See references/oauth-setup.md.
Core Workflow
Step 1: Define Tools
Tools are functions MCP clients can call. Define them using server.tool():
import { McpAgent } from "agents/mcp";
import { z } from "zod";
export class MyMCP extends McpAgent {
server = new Server({ name: "my-mcp", version: "1.0.0" });
async init() {
// Simple tool with parameters
this.server.tool(
"add",
{ a: z.number(), b: z.number() },
async ({ a, b }) => ({
content: [{ type: "text", text: String(a + b) }],
})
);
// Tool that calls external API
this.server.tool(
"get_weather",
{ city: z.string() },
async ({ city }) => {
const response = await fetch(`https://api.weather.com/${city}`);
const data = await response.json();
return {
content: [{ type: "text", text: JSON.stringify(data) }],
};
}
);
}
}
Step 2: Configure Entry Point
Public server (src/index.ts):
import { MyMCP } from "./mcp";
export default {
fetch(request: Request, env: Env, ctx: ExecutionContext) {
const url = new URL(request.url);
if (url.pathname === "/mcp") {
return MyMCP.serveSSE("/mcp").fetch(request, env, ctx);
}
return new Response("MCP Server", { status: 200 });
},
};
export { MyMCP };
Authenticated server — See references/oauth-setup.md.
Step 3: Test Locally
# Start server
npm start
# In another terminal, test with MCP Inspector
npx @modelcontextprotocol/inspector@latest
# Open http://localhost:5173, enter http://localhost:8788/mcp
Step 4: Deploy
npx wrangler deploy
Server accessible at https://[worker-name].[account].workers.dev/mcp
Step 5: Connect Clients
Claude Desktop (claude_desktop_config.json):
{
"mcpServers": {
"my-server": {
"command": "npx",
"args": ["mcp-remote", "https://my-mcp.workers.dev/mcp"]
}
}
}
Restart Claude Desktop after updating config.
Tool Patterns
Return Types
// Text response
return { content: [{ type: "text", text: "result" }] };
// Multiple content items
return {
content: [
{ type: "text", text: "Here's the data:" },
{ type: "text", text: JSON.stringify(data, null, 2) },
],
};
Input Validation with Zod
this.server.tool(
"create_user",
{
email: z.string().email(),
name: z.string().min(1).max(100),
role: z.enum(["admin", "user", "guest"]),
age: z.number().int().min(0).optional(),
},
async (params) => {
// params are fully typed and validated
}
);
Accessing Environment/Bindings
export class MyMCP extends McpAgent<Env> {
async init() {
this.server.tool("query_db", { sql: z.string() }, async ({ sql }) => {
// Access D1 binding
const result = await this.env.DB.prepare(sql).all();
return { content: [{ type: "text", text: JSON.stringify(result) }] };
});
}
}
Authentication
For OAuth-protected servers, see references/oauth-setup.md.
Supported providers:
- GitHub
- Auth0
- Stytch
- WorkOS
- Any OAuth 2.0 compliant provider
Wrangler Configuration
Minimal wrangler.toml:
name = "my-mcp-server"
main = "src/index.ts"
compatibility_date = "2024-12-01"
[durable_objects]
bindings = [{ name = "MCP", class_name = "MyMCP" }]
[[migrations]]
tag = "v1"
new_classes = ["MyMCP"]
With bindings (D1, KV, etc.):
[[d1_databases]]
binding = "DB"
database_name = "my-db"
database_id = "xxx"
[[kv_namespaces]]
binding = "KV"
id = "xxx"
Common Issues
"Tool not found" in Client
- Verify tool name matches exactly (case-sensitive)
- Ensure
init()registers tools before connections - Check server logs:
wrangler tail
Connection Fails
- Confirm endpoint path is
/mcp - Check CORS if browser-based client
- Verify Worker is deployed:
wrangler deployments list
OAuth Redirect Errors
- Callback URL must match OAuth app config exactly
- Check
GITHUB_CLIENT_IDandGITHUB_CLIENT_SECRETare set - For local dev, use
http://localhost:8788/callback
References
- references/examples.md — Official templates and production examples
- references/oauth-setup.md — OAuth provider configuration
- references/tool-patterns.md — Advanced tool examples
- references/troubleshooting.md — Error codes and fixes
FAQ
What does the building-mcp-server-on-cloudflare skill do?
Builds remote MCP (Model Context Protocol) servers on Cloudflare Workers with tools, OAuth authentication, and production deployment. Generates server code, configures auth providers, and deploys to Workers. Use when: user wants to "build MCP server", "create MCP tools", "remote MCP", "deploy MCP", add "OAuth to MCP", or mentions Model Context Protocol on Cloudflare. Also triggers on "MCP authentication" or "MCP deployment". Biases towards retrieval from Cloudflare docs over pre-trained knowledge.
How do I install building-mcp-server-on-cloudflare?
Run npx skills add https://developers.cloudflare.com --skill building-mcp-server-on-cloudflare in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/building-mcp-server-on-cloudflare/ (personal) or .claude/skills/building-mcp-server-on-cloudflare/ (project).
Which AI agents can use building-mcp-server-on-cloudflare?
Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.
Is building-mcp-server-on-cloudflare safe to install?
No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.
Who maintains building-mcp-server-on-cloudflare?
It is published by developers.cloudflare.com in developers.cloudflare.com. It has 161 recorded installs.
More from developers.cloudflare.com
cloudflare
developers.cloudflare.com
Discover and choose Cloudflare products for apps, APIs, AI agents, storage, networking, and security. Use for architecture and product selection, including when the user describes a need without naming a Cloudflare product; then find the relevant skill or documentation.
wrangler
developers.cloudflare.com
Run or troubleshoot Wrangler CLI commands in projects that have a wrangler.jsonc, wrangler.json, or wrangler.toml file, including local development, Previews, deployment, and resource management. For new projects and projects without a Wrangler configuration file, use the cf CLI instead.
workers-best-practices
developers.cloudflare.com
Cloudflare Workers best practices for production applications. Use when writing, reviewing, or configuring Workers.
durable-objects
developers.cloudflare.com
Build, debug, or review Cloudflare Durable Objects code for persistent state and coordination.
agents-sdk
developers.cloudflare.com
Build, debug, or review Cloudflare Agents SDK applications using the agents package.
web-perf
developers.cloudflare.com
Audit, diagnose, or optimize website loading and interaction performance, Core Web Vitals, and Lighthouse performance scores.
Popular devops & cloud skills
microsoft-foundry
microsoft/azure-skills
Build, deploy, evaluate, optimize, fine-tune, and manage Microsoft Foundry agents, models, and resources end to end. USE FOR: foundry, azd ai agent, azd provision/deploy, hosted agent scaffold/develop/run/deploy/troubleshoot, prompt agent create, managed harness agent create, GitHub Copilot harness agent, create agent, update agent, add tool to agent, invoke agent, agent insights, evaluate agent, batch eval, continuous eval, continuous monitoring, agent CI/CD, optimize prompt, improve prompt, optimize agent instructions, Agent Optimizer scaffold, dataset curation from traces, deploy model, model fine-tuning (SFT/DPO/RFT), Foundry project, RBAC, role assignment, permissions, quota, capacity, region, deployment failure, AI Services, create Foundry resource, knowledge index, customize deployment, onboard, availability, training-data, grader, distillation, large file upload. DO NOT USE FOR: Azure Functions, App Service, general Azure deploy (use azure-deploy), general Azure prep (use azure
azure-diagnostics
microsoft/azure-skills
Debug Azure production issues on Azure using AppLens, Azure Monitor, resource health, and safe triage. WHEN: debug production issues, troubleshoot app service, app service high CPU, app service deployment failure, troubleshoot container apps, container app 503 or target port mismatch, troubleshoot functions, function telemetry missing or stopped after a config/connection-string change, troubleshoot AKS, VM RDP, Linux SSH, VM black screen, can't connect to VM, reset VM password, NSG or firewall blocking, kubectl cannot connect, kube-system/CoreDNS failures, pod pending, crashloop, node not ready, upgrade failures, analyze logs, KQL, insights, image pull failures, cold start issues, health probe failures, resource health, root cause of errors, troubleshoot event hubs, troubleshoot service bus, messaging SDK error, AMQP connection failure, message lock lost, lock renewal during long-running processing, service bus dead letter.
azure-prepare
microsoft/azure-skills
Prepare azd-based Azure projects for deployment: generates azure.yaml, infrastructure (Bicep/Terraform), and Dockerfiles for the Azure Developer CLI (azd) workflow. USE ONLY when the user explicitly wants to use azd as the deployment tool, or the project already has an azure.yaml file. DO NOT USE FOR: non-azd deployments, Python App Service code-only deploys (use python-appservice-deploy), or cross-cloud migration (use azure-cloud-migrate). WHEN: prepare app for azd, create azure.yaml, set up azd infrastructure, modernize app for Azure with azd, deploy with azd, function app, timer trigger, service bus trigger, event-driven function, managed identity, generate Bicep, generate Terraform, create and deploy to Azure.
azure-ai
microsoft/azure-skills
Use for Azure AI: Search, Speech, OpenAI, Document Intelligence. Helps with search, vector/hybrid search, speech-to-text, text-to-speech, transcription, OCR. WHEN: AI Search, query search, vector search, hybrid search, semantic search, speech-to-text, text-to-speech, transcribe, OCR, convert text to speech.
azure-deploy
microsoft/azure-skills
Execute Azure deployments for ALREADY-PREPARED applications that have existing .azure/deployment-plan.md and infrastructure files. DO NOT use this skill when the user asks to CREATE a new application — use azure-prepare instead. This skill runs azd up, azd deploy, terraform apply, and az deployment commands with built-in error recovery. Requires .azure/deployment-plan.md from azure-prepare and validated status from azure-validate. WHEN: "run azd up", "run azd deploy", "execute deployment", "push to production", "push to cloud", "go live", "ship it", "bicep deploy", "terraform apply", "publish to Azure", "launch on Azure". DO NOT USE WHEN: "create and deploy", "build and deploy", "create a new app", "set up infrastructure", "create and deploy to Azure using Terraform" — use azure-prepare for these.
azure-validate
microsoft/azure-skills
Pre-deployment validation for Azure readiness. Run deep checks on configuration, infrastructure (Bicep or Terraform), RBAC role assignments, managed identity permissions, and prerequisites before deploying. WHEN: validate my app, check deployment readiness, run preflight checks, verify configuration, check if ready to deploy, validate azure.yaml, validate Bicep, test before deploying, troubleshoot deployment errors, validate Azure Functions, validate function app, validate serverless deployment, verify RBAC roles, check role assignments, review managed identity permissions, what-if analysis, validate Container Apps deployment.