AiMatch

Castov

Castov gives software developers browser-based utilities, a CLI, and an MCP server for tasks such as JSON formatting, timestamp conversion, and cron generation. Developers can run tools locally or expose them to MCP-compatible clients such as Cursor and Claude.

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Castov screenshot

Who it's for

  • Software developers who need quick browser tools for common tasks such as JSON formatting, timestamp conversion, and cron expressions.
  • Developers who want to run Castov utilities from a terminal or Docker container in development and CI/CD workflows.
  • Teams using Cursor or Claude that want to call developer utilities through an MCP server.

How it fits your workflow

In the browser, choose a utility from the tool directory and enter the value or data to process. The page says time, date, and converter inputs are handled locally rather than uploaded to Castov servers.

For terminal use, install the CLI with npm and run Castov commands locally. The page also describes a Docker image for running the CLI and MCP runtime.

For AI-assisted use, connect the MCP server to a compatible client such as Cursor or Claude so the client can use Castov utilities.

Pricing

Free: The site says all tools are free, with no account and no usage limits. Some collaboration, cloud, and external API features may require an account or additional configuration.

Free

Free; the page says there are no usage limits.

  • · Browser-based developer tools
  • · No account required for the general tools
  • · Some collaboration, cloud, and external API features may require an account or additional configuration

Prices checked on Nov 1, 2026 from the vendor's site. They can change; confirm before you buy.

Key features

Browser-based developer utilities
Offers tools for timestamps, dates, time zones, JSON, cron expressions, networking, cryptography, and other developer tasks. The page says these utilities execute locally in the browser.
CLI
Castov can be installed as a command-line tool using `npm i -g castov`. The page lists Node.js 18+ as a requirement.
MCP server
Exposes Castov utilities to MCP-compatible AI clients; the page specifically names Cursor and Claude.
Tool pipelines
The “Pipe to...” feature lets users pass the output of one utility to another, with examples including JSON to TypeScript interfaces and cron schedules to world time zones.
Encrypted sharing and sync
URL shares place compressed inputs, diffs, and settings in the URL hash fragment. The page also describes GitHub OAuth-based preference sync and RSA-OAEP encrypted Team Vaults.
Experimental developer labs
The site lists experimental tools including a Service Worker API Mocker, P2P Ghost Tunnel, Steganography Env Vault, and WebGL JSON explorer.

Works with

  • Cursor and Claude
  • GitHub OAuth
  • Docker

Limitations to know

  • The CLI requires Node.js 18+.
  • Some collaboration, cloud, and external API features may require an account or additional configuration.
  • Some features use network services by design: Env Vault uploads an encrypted copy, P2P Ghost Tunnel uses public STUN discovery, and Developer Canvas uses public WebRTC signaling servers that may receive connection metadata.

Getting started

npm i -g castov

Node.js 18+ for the CLI.

  1. Open the Castov site and browse the tool directory, or install the CLI with the command shown on the page.
  2. Run `castov` in a terminal after installation.
  3. For MCP use, follow the site's MCP server information and configure a compatible client such as Cursor or Claude.

Frequently asked questions

Is Castov free?

Yes. The page says all tools are free, with no account and no usage limits. It notes that the site may show ads in the future.

Is my data sent to a server?

The page says time, date, and converter inputs are not uploaded to Castov servers, and describes browser execution as local. Some features use the network by design: Env Vault uploads an encrypted copy, P2P Ghost Tunnel uses public STUN discovery with manual token exchange, and Developer Canvas connects to public WebRTC signaling servers that may receive connection metadata.

Which time zones are supported?

Castov supports IANA time zones available in the user's browser and applies daylight-saving-time rules for the selected date.

Should I use seconds or milliseconds for a Unix timestamp?

The page says to use the unit produced by the relevant system. It describes 10-digit values as seconds and 13-digit values as milliseconds, and says the converters can detect the unit.