Skip to main content
Glama

When you replace a preview, its local URL stays the same. New requests switch only after the replacement services pass readiness checks. Stop ends owned processes and retains managed database data.

Previewhost dashboard showing a frontend, API, PostgreSQL, Redis, and completed migration and seed jobs

Get started

Previewhost requires Node.js 22.23 or later. macOS and Linux support x64 and arm64. Windows requires x64. Native commands and automatic project owners run on macOS, Linux, and Windows. See the platform and database requirements. Linux requires procps (/bin/ps) and lsof (/usr/bin/lsof). Automatic unlock requires macOS 13 or later.

For an existing installation, read the reset instructions before updating.

Choose the interface you need:

Interface

Guide

Coding agent

MCP setup: register a client and ask it to preview your application.

Terminal

First preview with the CLI: run a frontend and backend, replace them, and stop them.

Node.js program

Node.js library: start a runtime, request a page, and close it.

Each guide includes its installation steps. The introduction explains how previews, environments, and project owners work.

Default lookup uses root preview.yaml, then preview.yml. If both exist, select one with --file or keep one default. New configurations save as preview.yaml only when neither file exists.

For a project with a configuration file and the global CLI installed:

previewhost inspect
previewhost start --allow-exec
previewhost dashboard

--allow-exec permits trusted commands and managed database operations with your user permissions, without a sandbox. The dashboard opens in your browser and needs its terminal to remain open. Closing it does not stop previews.

Related MCP server: @reachpad/mcp

Documentation

Task

Guide

Install or update Previewhost

Installation

Run a complete example

First preview with the CLI

Connect a coding agent

MCP setup

Describe your application

Write preview.yaml

Run services, migrations, and seeds

Services and jobs

Connect or manage local data

Databases

Supply private credentials

Secrets

Preview existing task checkouts

Worktrees

Inspect previews in the browser

Dashboard

Diagnose errors

Troubleshooting

Embed the runtime

Node.js library

Look up fields and commands

API and CLI reference

Check supported clients and frameworks

Integrations

Understand permissions and recovery

Security

The optional agent skill ships in the npm package under dist/skills/previewhost. Install it through your client's skill mechanism. MCP registration and skill installation are separate operations.

Reset required for earlier installations

This release uses ~/.local/share/previewhost for runtime storage and Previewhost names for managed Docker resources. It does not discover or migrate earlier runtime namespaces, Keychain secrets, or retained-data records. Existing files and resources are left intact.

  1. Before updating, stop earlier Previewhost owners with the installed version.

  2. If no encrypted keystore exists, run previewhost secrets init. Enter required secrets through private input.

  3. For new managed databases, choose a fresh --data-dir.

  4. Keep old data directories, Docker volumes, and Keychain items until you decide how to retain them.

For valuable old database data, use the earlier release to access and export it first. Use that release for any explicit cleanup of old data. Removing a record or generating a new password does not recover its database. See keystore recovery for backups and lost passwords.

Development

See CONTRIBUTING.md for source builds and verification. The documentation website renders the same Markdown guides with search, page outlines, and light and dark themes. Run npm run dev:docs after installing repository dependencies. Website code and build output are excluded from the npm package. The bundled agent skill includes its referenced guides and product screenshots.

See NOTICE for attribution and LICENSE for the MIT license.

Related MCP Connectors

Related MCP Servers

  • F
    license
    Not graded
    quality
    C
    maintenance
    Enables AI agents to investigate production incidents by exposing service health, logs, and deployment data through MCP tools.
    4 npm
    -
  • A
    license
    Not graded
    quality
    B
    maintenance
    Enables agent clients to safely connect to tools and execution resources through MCP with authorization, approvals, audit, chat-context isolation, SSH/Docker access, and long-running command session tracking.
    MIT