@deepseek-ai/dsh-session-messaging

Same-process messaging between live DeepSeek Harness sessions.

The plugin registers session_list, session_send, and session_messages. Delivery uses the public ctx.agents registry and Agent.followup(), so an idle target is woken and a busy target receives ordinary queued work. A bounded in-memory recent log (the latest 1,000 delivered messages) is kept only for session_messages replay and diagnostics; it is not a second delivery queue. Messages carry sender, target, UUID, and timestamp metadata.

This package intentionally does not implement cross-host transport. A future relay can replace the local backend while preserving the tool contract.

Known Limitations and Deferred Work

• Process boundary — sessions in another process or host are not visible; add an authenticated relay/backend before advertising cross-host delivery.
• In-memory retention — messages are lost when the plugin process exits and older than the latest 1,000 are evicted; durable inbox/outbox persistence is still deferred until a cross-process relay needs it.
• Delivery acknowledgement — the current result means the target was live and accepted the follow-up call, not that the target model processed it.

Model Experience

None, as session_list, session_send, and session_messages expose their schemas directly through the tool registry.

KV Cache effect

Independent tool schemas; sending a message changes only the target session's queued input and does not alter the sender's cached prompt prefix.