// free tool
Make your agent discoverable.
Build a spec-compliant A2A agent card, or paste an existing one to validate it. Both run in your browser; nothing is uploaded.
{
"protocolVersion": "0.3.0",
"name": "Invoice Assistant",
"description": "Answers questions about invoices and billing history, and drafts payment reminders.",
"url": "https://example.com/a2a",
"version": "1.0.0",
"capabilities": {
"streaming": false,
"pushNotifications": false,
"stateTransitionHistory": false
},
"defaultInputModes": [
"text/plain"
],
"defaultOutputModes": [
"text/plain"
],
"skills": [
{
"id": "search_invoices",
"name": "Search invoices",
"description": "Find invoices by customer, status or date range. Use when the user asks about billing history.",
"tags": [
"billing",
"search"
]
}
],
"securitySchemes": {
"bearer": {
"type": "http",
"scheme": "bearer"
}
},
"security": [
{
"bearer": []
}
]
}No issues, this card is well-formed and discoverable.
Building multi-agent systems? We do A2A integration and agent interop.
Talk to us about itQuestions
What is an agent card?
The /.well-known/agent-card.json file that lets other agents discover yours: its name, what skills it offers, the endpoint to call, and how to authenticate. A2A is to agent-to-agent delegation roughly what OpenAPI is to REST.
Why do skill descriptions matter so much?
Because a delegating agent reads them to decide whether your agent fits the task. A skill called 'search' described as 'searches' won't get chosen over a competitor that says what it searches and when to use it. It's the same dynamic as tool descriptions in a single agent's toolset.
Where does the file go?
At /.well-known/agent-card.json on the domain that hosts your agent, served as application/json with public read access and no auth on that path. Discovery has to work before authentication does.
Is A2A stable?
It's young and still moving. Pin the protocolVersion in your card and treat spec updates as recurring maintenance rather than a one-time build.
Does anything get sent to a server?
No. Both building and validating run entirely in your browser; there's no API call and nothing is stored.
// ready_when_you_are
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