HoldKit MCP Server

by peerfoundry Your server? Claim it

answering

HoldKit is answering right now. Last checked 1 min ago. It exposes 14 tools.

Idempotency keys, locks, timers, and inboxes for agents over MCP. No payments.

Uptime history 49 hours of history

49 hours agonow

100.0%

Uptime 24h

92 of 92 checks

Tools

read from the server

188 ms

Response time

average over 24h

open, no key

Access

streamable-http

Nothing serious here today

Today is the operative word: we check HoldKit every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 1 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add holdkit --transport http https://holdkit.peerfoundry.ai/mcp

Settings → Connectors → Add custom connector, then paste this address

https://holdkit.peerfoundry.ai/mcp

~/.codex/config.toml

[mcp_servers.holdkit]
url = "https://holdkit.peerfoundry.ai/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "holdkit": {
      "url": "https://holdkit.peerfoundry.ai/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "holdkit": {
      "type": "http",
      "url": "https://holdkit.peerfoundry.ai/mcp"
    }
  }
}

Available tools 14

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

inbox

inbox.ack

Mark inbox events done.

inbox.create

Create an inbox. Returns webhook and A2A URLs.

inbox.poll

Read inbox events after a cursor.

inbox.wait

Poll an inbox. block_ms is accepted and capped at 0 in this MVP, so the call returns current events.

kv.delete

Delete a value.

kv.get

Read a small value.

kv.set

Write a small value with a TTL. Emails and card numbers are rejected.

idem

idem.begin

Start an idempotency key or return the prior outcome. fingerprint is a hex hash.

idem.commit

Store the outcome reference for an idempotency key. scope (max 64) and owner are optional. When owner is omitted, the caller key hash is sent.

lock

lock.acquire

Take a lease lock. Returns a fencing token.

lock.release

Release a lock with its fencing token.

timer

timer.cancel

Cancel a timer.

timer.set

Schedule a durable timer. Delivery URLs must be public https.

keys

keys.create

Mint a pf_ caller key bound to one HoldKit namespace.

Endpoints

URL	Transport	State	Latency	Checked
https://holdkit.peerfoundry.ai/mcp	streamable-http	answering	82 ms	1 min ago

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HoldKit — questions

Answers built from our own checks of this server.

What can HoldKit do?

It exposes 14 tools, read directly from the server on our last check. Among them: idem.begin, idem.commit, inbox.ack, inbox.create, inbox.poll, inbox.wait and 8 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

What is HoldKit mostly used for?

Its tools cluster around inbox, kv and idem. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.

Is HoldKit working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 92 of 92 checks got a reply (100.0%), average response time 188 ms. The bar chart above shows every period we have measured.

How do I connect HoldKit?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does HoldKit need an API key?

No. HoldKit completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 14 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is HoldKit?

It answers our handshake in 188 ms on average, which is faster than 73% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.