feat(agents): message agents with or without Nodeterm

README.md

@@ -187,6 +187,8 @@ the PR as a readable severity, location, and finding table.
 | `gx branch finish --via-pr --wait-for-merge --cleanup` | Ship safely through a PR. |
 | `gx branch finish --fast` | Squash-merge a locally verified small change without local preflight or AI review. |
 | `gx agents status` | Show active agent lanes. |
+| `gx agents send --session <id> --message <text>` | Deliver safely to an idle agent or queue for its next turn. |
+| `gx agents inbox [--ack <message-id>]` | Read or acknowledge the authenticated standalone message queue. |
 | `gx cleanup` | Prune merged or stale worktrees. |
 
 Need the terminal cockpit? Run `gx cockpit`; see the

docs/agents-cockpit.md

@@ -167,6 +167,48 @@ gx agents locks --branch agent/codex/fix-auth-tests-2026-04-29-21-30 --json
 These inspection commands are lane-scoped. They require `--branch` so a
 human or cockpit pane must choose which sandbox to inspect.
 
+## Message an idle agent lane
+
+Send a message by canonical session id:
+
+```bash
+gx agents send \
+  --session agent__codex__fix-auth-tests \
+  --message "Re-run the focused auth test and report the result."
+```
+
+Or select the target by its recorded branch:
+
+```bash
+gx agents send \
+  --branch agent/codex/fix-auth-tests-2026-04-29-21-30 \
+  --message "Re-run the focused auth test and report the result."
+```
+
+Have the registered source agent run the command from its worktree. It may pass
+`--from-session <id>`; GitGuardex verifies that the caller descends from that
+session's live agent process. GitGuardex first attempts guarded live delivery
+to an active session whose activity is `done`, whose backend is tmux, and whose
+recorded pane still has the expected agent process in the foreground. The
+message is wrapped in a nonce-stamped outer envelope and pasted through a named
+tmux buffer. If the target is busy or its live pane cannot be safely verified,
+GitGuardex stores the authenticated message in a private, worktree-shared queue
+instead of dropping it.
+
+The target agent reads and acknowledges pending messages from its own
+registered process:
+
+```bash
+gx agents inbox
+gx agents inbox --ack <message-id>
+```
+
+The repo-scoped `gx` MCP exposes the same flow as `send_agent_message`,
+`read_agent_messages`, and `ack_agent_message`. This works without a Nodeterm
+server; caller-process and session ownership are still verified. Live-send
+success confirms paste and submission, not that the target agent read or acted
+on the message. Queued messages remain pending until acknowledged.
+
 ## Finish a lane
 
 Finish by branch: