Agent Callback Mailbox

us.inversolabsPublished by inversolabs.usOfficial publisherv0.1.54Updated Oct 24, 2026

Paid replay-safe callback inboxes for asynchronous agent tasks with structured MCP results.

VerifiedStreamable HTTPWeb executableProductivity & Workflow

Overview

AI-generated overview

A remote MCP endpoint providing paid, replay-safe callback inboxes that deliver structured results for asynchronous agent tasks.

What you can do
Create and use callback inboxes for asynchronous agent tasks, where results come back as structured MCP results rather than being polled for directly. Inboxes are described as replay-safe, so callbacks can be replayed without duplicating effects. The manifest lists no tools, so the exact operations are not documented; the description covers only the inbox and callback concept.
When to use it
Consider it when an assistant starts long-running or asynchronous tasks and needs a durable place for their results to be delivered back, with replay safety. It is not a fit for simple synchronous tool calls.
Requirements
A remote MCP client connecting to the hosted endpoint over streamable HTTP. The manifest declares no authentication, environment variables or headers, and no local package or runtime is needed.
Before you install
The service is described as paid, so using it may incur charges; confirm pricing before relying on it. The manifest declares no authentication, so check how inboxes are isolated and who can read or replay callbacks. No tools or documentation are provided, so behavior cannot be verified in advance.

Installation

In SourceWeft

  1. Open Agent Callback Mailbox in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/us.inversolabs%2Fagent-callback-mailbox/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "agent-callback-mailbox": {
      "type": "http",
      "url": "https://callbacks.inversolabs.us/mcp"
    }
  }
}

Tools

0
SourceWeft has not read this server's tools yet.

Version history

1
  1. v0.1.54LatestSep 16, 2026

Score

56% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts

    Publish an icon in the registry entry.

  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.

Other Inversolabs integrations

x402 Compatibility Intelligence

us.inversolabsOfficial publisher

Remote MCP server that lets an assistant preflight x402 payment compatibility, returning structured risk evidence and remediation guidance.

Streamable HTTPWeb executable
FinanceNot indexed yetOct 24, 2026

MCP Auth Preflight

us.inversolabsOfficial publisher

Remote MCP endpoint that checks OAuth compatibility for MCP servers and returns structured evidence with remediation guidance.

Streamable HTTPWeb executable
Security & MonitoringNot indexed yetOct 24, 2026