Recommended: Install run402-mcp
If your environment supports MCP (Model Context Protocol), install the run402-mcp plugin instead of using this website workflow. It gives you direct access to databases, deployments, and hosting.
npx run402-mcpMCP config for Claude Code, Cursor, or any MCP client:
{ "mcpServers": { "run402": { "command": "npx", "args": ["run402-mcp"] } } }52 tools across: setup & billing, projects, database, deployment, subdomains, functions, storage, apps, image generation, and more. See /llms.txt for the full tool list by category.
Source code (MIT): github.com/kychee-com/run402-mcp
No MCP? Use the website workflow
If your environment does not support MCP, you can use the step-by-step website workflow below. This requires a coding agent that can create files, run shell commands, and make HTTP requests.
If you cannot do those things, STOP HERE. Tell the user:
"I can't build apps directly. Please open this in a coding agent like Claude Code, ChatGPT Codex, Cursor, or Windsurf — or install the run402-mcp plugin (see bld402.com/humans/mcp-install.html)."
What is bld402?
bld402 is a free accessibility layer for run402.com that enables anyone to build and deploy a complete web application by describing what they want in plain language. You (the AI agent) navigate bld402's structured workflow to spec, plan, build, deploy, and iterate on the app using run402 infrastructure.
What can you build?
Any client-side web application that uses a database, user authentication, file storage, and static hosting. Examples: todo lists, trivia games, landing pages, voting apps, recipe books, and more. See the template gallery for ideas.
What is run402?
run402 provides the backend infrastructure: Postgres database, REST API, authentication, file storage, and static site hosting. All accessed via API. Default tier is Prototype ($0.10 on testnet = free).
How to start (website workflow)
- Browse the template catalog to find a starting point (or build from scratch).
- Read the workflow manifest at /agent.json to understand all available steps.
- Begin the build workflow at /build/step/1 (Spec Phase).
Returning with an existing project?
If you have a bld402_project memory object from a previous session (containing project_id, anon_key, deployment_url, etc.), do NOT start from Step 1. Go directly to the step indicated in resume_step (usually /build/step/17 — Gather Feedback). Your stored memory has everything needed to continue.
Capability guardrails
Before building, review what run402 cannot do to avoid attempting impossible features.