vtcode-a2a

Root AGENTS.md | Agent2Agent (A2A) Protocol support. Layer 0 crate — zero internal vtcode dependencies.

Module Groups

Area	Modules
Agent Card	agent_card — agent discovery and capability advertisement
Client	client — A2A protocol client
CLI	cli — CLI interface for A2A commands
Errors	errors — A2A-specific error types
RPC	rpc — JSON-RPC message types and protocol constants
Server	server — HTTP server (feature-gated: a2a-server)
Task Manager	task_manager — task lifecycle management
Types	types — core A2A protocol types (Message, Task, Part, etc.)
Webhook	webhook — push notification support

Rules

• The server module is feature-gated behind a2a-server — never import unconditionally.
• shutdown_signal_logged() is defined in lib.rs (not a separate module) — used by server.rs.
• Re-export facade in vtcode-core (a2a/mod.rs) must stay in sync with feature gates.

Gotchas

• server.rs uses crate::shutdown_signal_logged (not vtcode-core's shutdown) — local function.
• Feature flag chain: vtcode binary a2a-server -> vtcode-core a2a-server -> vtcode-a2a a2a-server.
• WebhookNotifier is always available (not feature-gated) — only the HTTP server is gated.