Once Agent MCP Server
by stringsofthemind-ossio.github.stringsofthemind-oss/oncev0.2.1
Developer assessment/setup MCP; admitted Once boundaries protect writes, not sibling connectors.
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Active2d ago
Install Once Agent MCP server
Install in Claude Code
claude mcp add once-agent -e ONCE_API_KEY='<once-api-key>' -- npx -y @once-agent/mcpInstall in Cursor
{
"mcpServers": {
"once-agent": {
"command": "npx",
"args": [
"-y",
"@once-agent/mcp"
],
"env": {
"ONCE_API_KEY": "<once-api-key>"
}
}
}
}Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).
Install in Claude Desktop
{
"mcpServers": {
"once-agent": {
"command": "npx",
"args": [
"-y",
"@once-agent/mcp"
],
"env": {
"ONCE_API_KEY": "<once-api-key>"
}
}
}
}Settings → Developer → Edit Config (claude_desktop_config.json), then restart.
Install in VS Code
{
"servers": {
"once-agent": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@once-agent/mcp"
],
"env": {
"ONCE_API_KEY": "<once-api-key>"
}
}
}
}Add to .vscode/mcp.json in your workspace.
Install in Windsurf
{
"mcpServers": {
"once-agent": {
"command": "npx",
"args": [
"-y",
"@once-agent/mcp"
],
"env": {
"ONCE_API_KEY": "<once-api-key>"
}
}
}
}Add to ~/.codeium/windsurf/mcp_config.json.
Configuration
| Variable | Required | Secret | Description |
|---|---|---|---|
| ONCE_API_KEY | — | yes | Optional key for Cloud checks. Without it once_verify_connection reports Cloud unconfigured/unverified and preserves local diagnostics. |
Freshness
Active — last maintenance signal 2d ago. The newest of the signals below sets the band.
Last commit (default branch)
2026-10-08 · 2d ago · GitHub
Latest release
2026-10-04 · 6d ago · GitHub · v0.1.25
Package published
no data · npm/PyPI
Registry entry updated
2026-10-08 · 2d ago · official registry · v0.2.1
FAQ
›How do I install the Once Agent MCP server in Claude Code?
Run: claude mcp add once-agent -e ONCE_API_KEY='<once-api-key>' -- npx -y @once-agent/mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.
›Does Once Agent require an API key?
Yes. It expects ONCE_API_KEY, of which 1 is a secret.
›Can I use Once Agent as a remote (hosted) MCP server?
No hosted endpoint is published; it runs locally over stdio.
›Is Once Agent in the official MCP registry?
Yes, as io.github.stringsofthemind-oss/once.