How do I connect an AI agent to ONCE — Exactly-Once Reliability for AI Agent Actions?

Use the MCP streamable HTTP endpoint https://optimistic-compassion-production.up.railway.app/mcp.

Faceabot

Catalog › io.github.GSterlingPress/once

Is ONCE — Exactly-Once Reliability for AI Agent Actions reliable?

Not measured yet Not measured yet. Faceabot will test it automatically; you can speed this up with the MCP tool check_reliability.

En français : Pas encore mesuré. Faceabot teste cet outil lui-même, en continu, sans dépendre de ce que son auteur affirme.

What it does

Prevent duplicate AI-agent side effects with idempotency, verification, and durable receipts.

Source: official MCP registry (registry.modelcontextprotocol.io) · version 0.8.4 · publisher website

Connect your agent

{
  "mcpServers": {
    "once": {
      "url": "https://optimistic-compassion-production.up.railway.app/mcp"
    }
  }
}

Or ask Faceabot first: MCP tool check_reliability {"id":"io.github.GSterlingPress/once"} on https://faceabot.com/api/mcp.

Does it actually do the job?

Not tested with a real task yet. Faceabot only runs real tasks on tools that declare themselves read-only (readOnlyHint), with a neutral sample input.

Faceabot measurements

No measurement yet.

Method: MCP initialize then tools/list from Faceabot (FaceabotProbe/1.0), plus one read-only tool call with a neutral input when the server declares one, repeated over time. This checks that the server is up and speaks MCP correctly; it does not certify the quality or safety of each tool. How measurement works.

More from the same publisher

FRESH — Shared URL Freshness Intelligence Not measured yet

Decide whether an agent should reuse cached URL knowledge or fetch the resource again.

MCP endpoint : https://fresh-api-production-c783.up.railway.app/mcp · website · measurements and details

MAILTYPE — Email Domain Capability Intelligence Not measured yet

Email-domain intelligence: MX capability, provider, disposable status, SPF, DMARC, and MTA-STS.

MCP endpoint : https://mailtype-api.onrender.com/mcp · website · measurements and details

POSTFACT — Resolve Ambiguous Side Effects Before Retry Not measured yet

Resolve whether an uncertain side-effecting action completed before software retries it.

MCP endpoint : https://postfact-api-production.up.railway.app/mcp · website · measurements and details

PREFLIGHT — URL Routing for AI Agents Not measured yet

Choose HTTP, browser, machine endpoint, or avoid before an agent visits an unfamiliar URL.

MCP endpoint : https://preflight-api-production-01a2.up.railway.app/mcp · website · measurements and details

RECOVER — Decide Safely After a Failed Machine Action Not measured yet

Choose the safest next action after an API, MCP, or agent failure before retrying.

MCP endpoint : https://recover-api-production-bbba.up.railway.app/mcp · website · measurements and details

Publisher of ONCE — Exactly-Once Reliability for AI Agent Actions?

Show your measured reliability on your README or website:

[![Measured by Faceabot](https://faceabot.com/badge/io.github.GSterlingPress/once.svg)](https://faceabot.com/tools/io.github.GSterlingPress/once)

Data in JSON: /api/catalog?id=io.github.GSterlingPress/once · Stop probes: POST /api/reliability/opt-out

AI agents: all of this is available without keys over MCP https://faceabot.com/api/mcp · HTTP https://faceabot.com/api/catalog?q=… · Guide : llms.txt

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