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Alphorn

Let AI agents notify you on Slack, Telegram, email, SMS, or push via an Alphorn webhook.

Automation & WorkflowTypeScriptv0.1.1

Alphorn MCP Server

MCP server for Alphorn, the open-source notification router. It gives AI agents (Claude Code, Claude Desktop, Cursor, Codex, and any other MCP client) a send_notification tool, so an agent can tell you when a task finishes, fails, or needs your decision, on whatever channel you configured in Alphorn: Slack, Telegram, Discord, email, SMS, push, and more.

Works with the hosted service at app.alphorn.dev and with self-hosted Alphorn.

Setup

  1. Create a webhook in Alphorn and copy its Endpoint URL, plus its API key if you switched on Require API key (docs).
  2. Add the server to your MCP client with two environment variables:
VariableValue
ALPHORN_WEBHOOK_URLEndpoint URL, e.g. https://app.alphorn.dev/n/V1StGXR8_Z5jdHi6B-myT
ALPHORN_API_KEYWebhook API key (alp_...). Leave unset if the webhook does not require one.

Claude Code

claude mcp add alphorn -s user \
  -e ALPHORN_WEBHOOK_URL=https://app.alphorn.dev/n/V1StGXR8_Z5jdHi6B-myT \
  -e ALPHORN_API_KEY=alp_... \
  -- npx -y @alphorn/mcp

Claude Desktop (one-click bundle)

Download alphorn.mcpb from the latest release and open it. Claude Desktop asks for the Endpoint URL and API key.

Claude Desktop, Cursor, and other JSON-configured clients

Add to claude_desktop_config.json, ~/.cursor/mcp.json, or your client's MCP config:

{
  "mcpServers": {
    "alphorn": {
      "command": "npx",
      "args": ["-y", "@alphorn/mcp"],
      "env": {
        "ALPHORN_WEBHOOK_URL": "https://app.alphorn.dev/n/V1StGXR8_Z5jdHi6B-myT",
        "ALPHORN_API_KEY": "alp_..."
      }
    }
  }
}

OpenAI Codex CLI

# ~/.codex/config.toml
[mcp_servers.alphorn]
command = "npx"
args = ["-y", "@alphorn/mcp"]
env = { ALPHORN_WEBHOOK_URL = "https://app.alphorn.dev/n/V1StGXR8_Z5jdHi6B-myT", ALPHORN_API_KEY = "alp_..." }

Tool

send_notification

ArgumentTypeRequiredDescription
messagestringyesWhat happened and what the agent needs from you (max 4,000 characters)
titlestringnoShort title, e.g. my-app - tests passing (max 200 characters)
priorityinteger 1-5no2 = finished, 3 = needs input, 4 = blocked or failed, 5 = urgent
tagsstring[]noTags to filter and route on in Alphorn, e.g. ["ai-agent", "completed"]

The tool wraps Alphorn's send endpoint. For direct HTTP use, see the API reference and the OpenAPI 3.1 specification.

Use Alphorn's filters to decide where each notification goes, for example SMS only for priority 4 and above.

Development

pnpm install
pnpm test   # builds, then runs the tests against a local fake endpoint

Releasing

  1. Bump version in package.json, server.json (both fields), manifest.json, and VERSION in src/server.ts.
  2. npm publish --access public
  3. Push a v<version> tag (or run the Publish to MCP Registry workflow): it publishes server.json to the MCP Registry via GitHub OIDC
  4. pnpm bundle, then attach alphorn.mcpb to a GitHub release

License

AGPL-3.0-or-later

Installation

Source-derived launch command. Check the maintainer’s required arguments and credentials before running:

bash
npx -y @alphorn/mcp

Set up in your AI client

Merge this template into ~/Library/Application Support/Claude/claude_desktop_config.json. Keep existing servers. Add any arguments, credentials, and permissions required by the maintainer; this template has not been install-tested.

json
{
  "mcpServers": {
    "io-github-alphorn-dev-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@alphorn/mcp"
      ]
    }
  }
}

Restart Claude Desktop completely for changes to take effect. Confirm the server appears connected in the client’s tool list, then try a read-only example from its documentation.

Claude Desktop setup reference

Package

@alphorn/mcpnpm

Compatible MCP Clients

Alphorn works with any MCP-compatible client. Copy the config snippet from the Configuration section above and add it to the file shown for your client, then restart the application.

  • Claude Desktop~/Library/Application Support/Claude/claude_desktop_config.jsonRestart Claude Desktop completely for changes to take effect.
  • Cursor~/.cursor/mcp.jsonRestart Cursor for changes to take effect.
  • VS Code.vscode/mcp.jsonReload VS Code window for changes to take effect.
  • Windsurf~/.codeium/windsurf/mcp_config.jsonRestart Windsurf for changes to take effect.
  • Claude Code.mcp.jsonSave at the project root, then start Claude Code in that project and review the MCP server approval prompt. Keep real credentials out of shared files.

Learn More