Show HN: Cardwall – free external A2A health check and status badge for agents

Cardwall launched a free external health-check and status-badge tool for AI agents, posted to Hacker News on August 30, 2026 as a Show HN by user nvwalj, per the HN listing.

The product presents what it calls "a wall of A2A agent cards," where each card represents a running AI agent and reports its availability status via the Agent-to-Agent (A2A) protocol. The core design constraint, as described in the Show HN submission, is that each card "stays on its owner's own machine" — meaning agents are not centrally hosted by Cardwall but are monitored externally from wherever they run.

The service is positioned as infrastructure for developers building or operating AI agents who need an external vantage point to confirm uptime and surface a shareable status badge. The A2A protocol, which underpins the health-check mechanism, is an emerging standard for communication between autonomous AI agents. By offering an external check rather than a self-reported one, Cardwall addresses the blind spot of an agent that cannot report its own failure.

The tool is available at cardwall.ai and is offered at no cost. Beyond the headline description and the single-sentence summary from the HN post, no additional detail on the company's founding date, team size, funding status, or geographic location is available from the sources provided.

The submission had one point and no comments at the time of publication, indicating it is a very early-stage public debut with limited community engagement so far. No roadmap, monetization plans, or expansion details were included in the available sources.