A2A preview

Agent-to-agent access exposes the same capability surface as MCP over the A2A protocol. Discover the agent via its card, then send messages to a skill.

Surface v2.3.6 - last updated 29 Oct 2026

Agents

Each side is its own agent with its own skills, and the path decides which credential is accepted — the same rule as the MCP endpoints.

  • /api/a2a/candidate — a candidate in their own rinkats space, with a candidate key (rkc_) or an OAuth token granted the candidate scope. A candidate belongs to no organisation.
  • /api/a2a/recruiter — an organisation's desk, with an rk_ key or an OAuth token.
  • /api/a2a/interviewer — an interviewer, with an rk_ key scoped to interviewer or an OAuth token granted the interviewer scope.

Agent card

Each agent's card is at /api/a2a/<side>/agent-card. The well-known path serves the recruiter card:

curl https://www.rinkats.com/api/a2a/candidate/agent-card curl https://www.rinkats.com/.well-known/agent-card.json

Send a message

POST a JSON-RPC message/send to the agent's endpoint, naming a skill (one of that side's MCP tools) and passing arguments as a data part. Authenticate with a Bearer key or an OAuth 2.1 access token, as for MCP.

curl -X POST https://www.rinkats.com/api/a2a/candidate \ -H "Authorization: Bearer rkc_p_…" \ -H "Content-Type: application/json" \ -d '{"jsonrpc":"2.0","id":1,"method":"message/send", "params":{"message":{"skillId":"list_my_applications", "parts":[{"kind":"data","data":{}}]}}}'
Preview. The A2A surface mirrors the packaged MCP tools; message shapes may change before general availability. Auth is the same as MCP — a Bearer key or an OAuth 2.1 access token.