Project Gumball MCP MCP server

An official MCP server from Project Gumball that exposes a portfolio of 25 small utility tools, including cron translation, JSON-to-TypeScript conversion, regex explanation, timezone conversion, and data validation. It serves as a unified endpoint for agents to access these capabilities via Streamable HTTP without authentication.

Endpoint and access

No sign-in: your client connects and lists tools immediately, with no account or key.

No sign-inEndpoint checked 2026-10-05Operated by Project Gumball

MCP endpoint (Streamable HTTP)

https://gumballtools.com/api/mcp

Vendor documentation

What you can do with it

Translate cron expressions to plain English and vice versa
Convert JSON payloads into TypeScript types and Zod schemas
Explain regular expressions and detect catastrophic backtracking
Validate JSON, YAML, XML, and CSV data with specific error fixes

Tools advertised by the last live check:

cron_explain
cron_build
cron_next_runs
json_to_types
regex_explain
timezone_convert
color_analyse
vocab_draw
vocab_check
body_metrics
due_date
round_cash_total
rounding_impact
price_band
offside
offside_rule_contrast
check_digit_run
amortize_schedule
iso_week_run
validate_json
validate_yaml
validate_xml
validate_csv
validate_auto
equation_steps_run

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers a Streamable HTTP server. Use --scope project to write .mcp.json for the repo.

Claude Code configuration

claude mcp add --transport http project-gumball-mcp https://gumballtools.com/api/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).

Codex configuration

codex mcp add project-gumball-mcp --url https://gumballtools.com/api/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable project-gumball-mcp in your MCP settings.

Cursor configuration

{
  "mcpServers": {
    "project-gumball-mcp": {
      "url": "https://gumballtools.com/api/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure). The type must be streamableHttp for a remote HTTP server.

Cline configuration

{
  "mcpServers": {
    "project-gumball-mcp": {
      "type": "streamableHttp",
      "url": "https://gumballtools.com/api/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start project-gumball-mcp and inspect its tools.

VS Code configuration

{
  "servers": {
    "project-gumball-mcp": {
      "type": "http",
      "url": "https://gumballtools.com/api/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.

Gemini CLI configuration

gemini mcp add --transport http project-gumball-mcp https://gumballtools.com/api/mcp

Claude Desktop

Merge this into claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\), then restart Claude Desktop.

Claude Desktop configuration

{
  "mcpServers": {
    "project-gumball-mcp": {
      "url": "https://gumballtools.com/api/mcp"
    }
  }
}

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.

Windsurf configuration

{
  "mcpServers": {
    "project-gumball-mcp": {
      "serverUrl": "https://gumballtools.com/api/mcp"
    }
  }
}

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