Scan at scaleSites with a broken A2A agent card
Sites with a broken A2A agent card
A site-wide report: one row per host, over the agent_card rows the crawl emitted.
What this report returns
An A2A agent card (/.well-known/agent-card.json) is a site's published identity for its agent: who it is, what it can do, and how to reach it.
These sites serve a card other agents can't trust or use: not a JSON object, an A2A-required field missing (name, description, version, capabilities, modes, skills, or a coherent endpoint), or a structurally malformed signature.
How to fix it. Complete the card per the A2A specification: every required field (a required array must hold at least one element), each skill carrying id, name, description and tags, and every supportedInterfaces entry carrying url, protocolBinding and protocolVersion; unsigned cards are fine, but a signatures field must be well-formed.
The columns it shows
Every defect this technology can carry is a column in the grid, worst first, so nothing is hidden behind a filter you have to know to apply.
- Host
host - Agent Card Valid
agentCardValid - A2A Agent Card Conformance Issue Detected
agentCardConformanceIssueDetected - Agent Card Findings
agentCardFindings - Agent Card Agent Name
agentCardAgentName - Agent Card Missing Field Names
agentCardMissingFieldNames - Agent Card Endpoint URLs
agentCardEndpointUrls - Agent Card Invalid JSON
agentCardInvalidJson - Agent Card Missing Fields
agentCardMissingFields - Agent Card Endpoint Not A2A
agentCardEndpointNotA2A - Agent Card Invalid Signature
agentCardInvalidSignature - Agent Card Endpoint Unverified
agentCardEndpointUnverified
About A2A agent card
Declares an agent this site operates, for agent-to-agent work.
Read how A2A agent card is checked, including the specification it is validated against and a worked correct and broken example.
Running it
This report ships in the Lumar agent-readiness container and appears on any project it is linked to, on every crawl. See the whole set, or check a single URL with the scanner on this site, which runs the same code with no account.