An agent can now work on a linked environment's threads through the same T3
MCP tools. t3_project_list, orchestrator_capabilities, t3_thread_launch,
t3_thread_list, t3_thread_read, t3_thread_send, t3_thread_wait and
t3_thread_interrupt take an optional environmentId; t3_environment_links
lists the links.

Each tool's own access declaration still runs here first, so a read-only or
ended caller is refused before anything leaves. The forwarded call carries
the caller's modes in T3-Mode-Limit, and the linked environment holds it to
those and the link's access. Retry keys are hashed with the caller's
namespace, since every caller here shares the link's one session there. A
forwarded wait goes out in pieces of at most 50 s so no route drops it idle.
A remote launch cannot carry attachments yet.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>