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mcp/harbor
VS Code

once for VS Code

io.github.stringsofthemind-oss/once

Execution-safety MCP for AI coding agents protecting consequential writes from unsafe retries.

client:VS Code transport:stdio runtime:npm

Install once in VS Code

.vscode/mcp.json 

{
  "inputs": [
    {
      "type": "promptString",
      "id": "once-api-key",
      "description": "ONCE_API_KEY",
      "password": true
    }
  ],
  "servers": {
    "once": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@once-agent/mcp"
      ],
      "env": {
        "ONCE_API_KEY": "${input:once-api-key}"
      }
    }
  }
}

VS Code prompts for each input the first time the server starts, so no secret is written to the file. VS Code docs

once in other clients

once MCP server