How to use .mcp.json builder
- Optionally paste your package.json and tick what else your repository contains.
- Review the detected MCP servers and tick or untick any.
- Copy or download .mcp.json and commit it at the root of your repository.
- Set the environment variables it names, such as SUPABASE_ACCESS_TOKEN, in your shell, not in the file.
What .mcp.json does
The Model Context Protocol lets a coding agent use tools for the systems your project depends on: query the Supabase database and read its logs, look up Sentry errors, check Vercel deployments, drive a browser with Playwright, or read GitHub issues. A .mcp.json file at the root of a repository lists the MCP servers an agent such as Claude Code should start for that project, so everyone on the team gets the same tools.
How servers are recommended
Recommendations come from the registry WeaveAI Ready uses when it scores repositories for coding agents. Each server is matched to evidence: @supabase/supabase-js or a supabase folder suggests the Supabase server, any @sentry package suggests Sentry, Next.js or a vercel.json suggests Vercel, a Prisma schema or pg suggests Postgres, and a .github folder suggests GitHub. Paste your package.json and tick what else your repository has, and the matching servers are ticked for you. Tick or untick any to adjust.
Detection runs in your browser. Your package.json is never uploaded or saved.
Keeping secrets out of the file
The generated file refers to credentials as environment variables, such as ${SUPABASE_ACCESS_TOKEN} or ${STRIPE_SECRET_KEY}. Agents read them from your environment when they start the server, so the file is safe to commit. Never replace those placeholders with real keys in a file that goes into version control; set them in your shell or your secrets manager instead.
Servers marked as remote connect over HTTPS to the vendor's hosted endpoint and usually ask you to sign in the first time; servers run with npx or uvx start locally on your machine.
Example
A Next.js app that uses Supabase, deploys to Vercel and keeps its code on GitHub gets four entries: supabase, run locally with npx and a project reference; vercel and github, each a hosted HTTPS endpoint; and playwright if its tests use Playwright. The file is a dozen lines of JSON under a single mcpServers key, ready to commit next to package.json.
Questions
- What is an MCP server?
- A Model Context Protocol server gives a coding agent tools for one system, such as reading Sentry issues, querying a Postgres database or checking Vercel deployments. .mcp.json lists the servers an agent should start for this repository.
- Where do the recommendations come from?
- From the same registry WeaveAI Ready uses when it scores a repository, which matches servers to dependencies and files such as @supabase/supabase-js or prisma/schema.prisma.
- Is my package.json uploaded?
- No. Detection runs in your browser and nothing is saved.