junobuild-mcp-server

Unofficial MCP server for Juno. Not affiliated with or endorsed by the Juno team.

Manage satellites, hosting, serverless functions, changes and more through any MCP-compatible client. Includes a built-in documentation tool to access Juno's official guides and references.

Features

• 15 tools across 6 domains — CLI coverage for identity, config, hosting, functions, changes, and documentation
• Progress streaming — long-running operations (deploy, publish, upgrade) emit real-time progress updates via MCP progress notifications
• Automatic retry — network-dependent operations can retry on transient failures with exponential backoff
• CLI binary caching — resolves juno binary path once, eliminating npx overhead on every call
• Smart error handling — all tools propagate isError based on CLI exit codes, with clean error messages
• Config file writing — juno_config_init can write config files directly to disk
• Docs caching — documentation responses cached for 1 hour to reduce latency

Setup

1. Add to your MCP client

No install needed — npx handles downloading automatically.

{
  "mcpServers": {
    "junobuild": {
      "command": "npx",
      "args": ["-y", "junobuild-mcp-server"]
    }
  }
}

2. Authenticate the Juno CLI

The server wraps @junobuild/cli, which must be installed and authenticated:

npm i -g @junobuild/cli
juno login

For non-interactive environments (CI, headless), set the JUNO_TOKEN environment variable or use the --mode and --profile flags available on every tool.

Note: The juno_create_project tool does NOT use the interactive create-juno CLI. Instead it:

1. Scaffolds a Vite project (React, Next.js, Svelte, Angular, or Vue)
2. Creates a juno.config.ts file

This allows fully non-interactive project creation.

Documentation Access

The juno_docs tool fetches documentation directly from the GitHub repo, with responses cached for 1 hour:

juno_docs({ topic: "build_datastore" })        → Datastore guide
juno_docs({ topic: "build_authentication" })   → Authentication overview
juno_docs({ topic: "reference_cli" })        → CLI reference
juno_docs({ topic: "guides_local_development" }) → Local development guide

Topic keys use underscore naming matching folder hierarchy: build_<feature>, reference_cli_<command>, guides_<framework>. Full list: see TODO.md for all 159 topics.

Tools

Domain	Tools
Identity	juno_version, juno_run
Config	juno_config_init, juno_config_apply, juno_create_project
Hosting	juno_hosting_deploy, juno_hosting_clear, juno_hosting_prune
Functions	juno_functions_build, juno_functions_eject, juno_functions_publish, juno_functions_upgrade
Changes	juno_changes_list, juno_changes_apply, juno_changes_reject
Docs	juno_docs

Key Parameters

Several tools support optional parameters for enhanced reliability and UX:

Parameter	Type	Tools	Description
retry	boolean	deploy, publish, upgrade	Automatically retry on transient network failures (up to 3 attempts with exponential backoff: 1s → 2s → 4s)
progress	boolean	deploy, publish, upgrade	Stream real-time progress updates during long-running operations (build status + upload batch progress)
writeFile	boolean	juno_config_init	Write the config file directly to disk instead of returning text for preview

Prerequisites

• Node.js >= 18
• @junobuild/cli — installed and authenticated (not needed for juno_version or juno_docs)
• Juno project with juno.config.ts/js/json (for config/hosting operations)

Development

npm run build        # Compile TypeScript to dist/
npm run dev          # Watch mode (development)
npm run start        # Run compiled dist/index.js
npm run clean        # Remove dist/

Publishing

npm run changeset    # Create a changeset (version bump + changelog entry)
npm run version      # Apply changesets → bump version
npm run release      # Publish to npm

License

MIT