ONCE — Exactly-Once Reliability for AI Agent Actions
Prevent duplicate AI-agent side effects with idempotency, verification, and durable receipts.
MCP server · by GSterlingPress
About
ONCE — Exactly-Once Reliability for AI Agent Actions is an MCP server published by GSterlingPress. Marketplaces we read that list it: 1 (Official MCP Registry). We first saw it on 2026-10-11 and have recorded no change since. As of our marketplace pass on 2026-10-13.
What it asks for
- Runs remotely
None of the marketplaces we read publishes its tools or the settings it asks for.
What it declares, asks for and runs, in full
Only install plugins from developers you trust. We list what marketplaces publish and do not test plugins.
Works with
- Claude Code
- Codex
- Cursor
- VS Code
- Copilot CLI
A one-click link opens the client, which asks you to confirm before it adds the server.
From the marketplaces that list it and the MCP transport it declares, as each client documents them. We do not test plugins.
Connect
Commands and configs built only from what its marketplaces declare. We do not run them for you and do not test plugins.
As a remote MCP server
Built from what Official MCP Registry declares.
claude mcp add --transport http once https://optimistic-compassion-production.up.railway.app/mcp[mcp_servers.once]
url = "https://optimistic-compassion-production.up.railway.app/mcp"{
"mcpServers": {
"once": {
"url": "https://optimistic-compassion-production.up.railway.app/mcp"
}
}
}Where it is published
| Marketplace | Status | Version | Figures | Verified | First seen |
|---|---|---|---|---|---|
| Official MCP Registry (Open the registry record) | Listed | 0.8.4 | Forks (GitHub): 0 Stars (GitHub): 0 |
Not marked |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
What changed
Nothing has moved on this plugin since we started watching it.
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Found by meaning, not by shared code or a shared repository: similar plugins stay separate products, and this is not a review or a recommendation.
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Data comes from the Official MCP Registry (registry.modelcontextprotocol.io), CC0 1.0. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.