Koskamo

Once MCP

An MCP server providing execution safety for side-effecting AI agent tools. It ensures idempotency and safe retries for consequential writes like refunds, bookings, and payments, protecting against unsafe duplicate execution after ambiguous timeouts or lost responses. It supports automatic classification of agent tools as bypass, protect, or fail-closed unknown.

Package and access

Local package with source-attributed installation metadata. Koskamo does not execute packages during review.

Once MCP logo, by stringsofthemind-ossCommunity listingLocal stdioSource reviewed; not executedPublished by stringsofthemind-oss
Vendor documentation

What you can do with it

  • Protect refunds from duplicate execution
  • Secure bookings against unsafe retries
  • Ensure safe payments processing
  • Classify agent tools as bypass or protect

Source and maintenance

Community listingRegistry 0.2.1
mcp-registry: io.github.stringsofthemind-oss/once@0.2.1Source repository
Maintenance checked

Packages and installation

Source-provided package data. Koskamo has not executed or live-probed this package.

@once-agent/mcp 0.2.1

npm
@once-agent/mcp package definition
{
  "version": "0.2.1",
  "transport": "stdio",
  "identifier": "@once-agent/mcp",
  "registryType": "npm",
  "environmentVariables": [
    {
      "name": "ONCE_API_KEY",
      "format": "string",
      "description": "Optional key for Cloud checks. Without it once_verify_connection reports Cloud unconfigured/unverified and preserves local diagnostics."
    }
  ]
}

Tools

Reported by the attributed source; not independently observed by Koskamo.

No tool definitions available.

Connect from your client

Each snippet configures the same source-provided package; replace placeholders before 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.

Cursor

Merge this local stdio configuration, replace every placeholder environment value, and restart Cursor. Koskamo has not executed this package.
Cursor configuration
{
  "mcpServers": {
    "once-mcp-once-agent-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@once-agent/mcp@0.2.1"
      ],
      "env": {
        "ONCE_API_KEY": "<YOUR_ONCE_API_KEY>"
      }
    }
  }
}

Cline

Merge this local stdio configuration, replace every placeholder environment value, and restart Cline. Koskamo has not executed this package.
Cline configuration
{
  "mcpServers": {
    "once-mcp-once-agent-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@once-agent/mcp@0.2.1"
      ],
      "env": {
        "ONCE_API_KEY": "<YOUR_ONCE_API_KEY>"
      }
    }
  }
}

VS Code

Merge this local stdio configuration, replace every placeholder environment value, and restart VS Code. Koskamo has not executed this package.
VS Code configuration
{
  "servers": {
    "once-mcp-once-agent-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@once-agent/mcp@0.2.1"
      ],
      "env": {
        "ONCE_API_KEY": "<YOUR_ONCE_API_KEY>"
      }
    }
  }
}

Claude Desktop

Merge this local stdio configuration, replace every placeholder environment value, and restart Claude Desktop. Koskamo has not executed this package.
Claude Desktop configuration
{
  "mcpServers": {
    "once-mcp-once-agent-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@once-agent/mcp@0.2.1"
      ],
      "env": {
        "ONCE_API_KEY": "<YOUR_ONCE_API_KEY>"
      }
    }
  }
}

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