Yes, over open standards. Each Heidi install publishes a signed A2A agent card at a well-known URL, speaks MCP for tools, and can discover and invoke external agents, with trust controls on who may call in.
Agent-to-agent is not a walled garden play: it is A2A v1.0 plus MCP, the converging standards, with cryptographically signed identity so peers can verify who they are talking to.
Inbound trust is explicit: callers must be declared peers, and discovery can be public or authenticated per install.